Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 80
Filter
Add more filters

Complementary Medicines
Country/Region as subject
Publication year range
1.
Virus Res ; 340: 199296, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38065302

ABSTRACT

The prevalence of multidrug-resistant highly virulent Klebsiella pneumoniae (MDR-hvKP) requires the development of new therapeutic agents. Herein, a novel lytic phage vB_KpnS_ZX4 against MDR-hvKP was discovered in hospital sewage. Phage vB_KpnS_ZX4 had a short latent period (5 min) and a large burst size (230 PFU/cell). It can rapidly reduce the number of bacteria in vitro and improve survival rates of bacteremic mice in vivo from 0 to 80 % with a single injection of 108 PFU. LysZX4, an endolysin derived from vB_KpnS_ZX4, exhibits potent antimicrobial activity in vitro in combination with ethylenediaminetetraacetic acid (EDTA). The antimicrobial activity of LysZX4 was further enhanced by the fusion of KWKLFKI residues from cecropin A (LysZX4-NCA). In vitro antibacterial experiments showed that LysZX4-NCA exerts broad-spectrum antibacterial activity against clinical Gram-negative bacteria, including MDR-hvKP. Moreover, in the mouse model of MDR-hvKP skin infection, treatment with LysZX4-NCA resulted in a three-log reduction in bacterial burden on the skin compared to the control group. Therefore, the novel phages vB_KpnS_ZX4 and LysZX4-NCA are effective reagents for the treatment of systemic and local MDR-hvKP infections.


Subject(s)
Anti-Bacterial Agents , Bacteriophages , Mice , Animals , Anti-Bacterial Agents/pharmacology , Endopeptidases/pharmacology , Klebsiella pneumoniae
2.
Int J Biol Macromol ; 242(Pt 2): 124809, 2023 Jul 01.
Article in English | MEDLINE | ID: mdl-37178877

ABSTRACT

Herein, we described for the first time, an efficient biogenic synthesis of APTs-AgNPs using acid protease from Melilotus indicus leaf extract. The acid protease (APTs) has an essential role in the stabilization, reduction, and capping of APTs-AgNPs. The crystalline nature, size, and surface morphology of APTs-AgNPs were examined using different techniques such as XRD, UV, FTIR, SEM, EDS, HRTEM, and DLS analysis. The generated APTs-AgNPs demonstrated notable performance as dual functionality (photocatalyst and antibacterial disinfection). By destroying 91 % of methylene blue (MB) in <90 min of exposure, APTs-AgNPs demonstrated remarkable photocatalytic activity. APTs-AgNPs also showed remarkable stability as a photocatalyst after five test cycles. Furthermore, the APTs-AgNPs was found to be a potent antibacterial agent with inhibition zones of 30(±0.5 mm), 27(±0.4 mm), 16(±0.1 mm), and 19(±0.7 mm) against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, respectively, under both light and dark conditions. Furthermore, APTs-AgNPs effectively scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, demonstrating their potent antioxidant activity. The outcomes of this study thus demonstrates the dual functionality of APTs-AgNPs produced using the biogenic approach method as a photocatalyst and an antibacterial agent for effective microbial and environmental control.


Subject(s)
Metal Nanoparticles , Peptide Hydrolases , Peptide Hydrolases/pharmacology , Silver/pharmacology , Silver/chemistry , Metal Nanoparticles/chemistry , Plant Extracts/pharmacology , Plant Extracts/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Endopeptidases/pharmacology , Escherichia coli , Microbial Sensitivity Tests
3.
Viruses ; 15(2)2023 02 13.
Article in English | MEDLINE | ID: mdl-36851734

ABSTRACT

The challenge of antibiotic resistance has gained much attention in recent years due to the rapid emergence of resistant bacteria infecting humans and risking industries. Thus, alternatives to antibiotics are being actively searched for. In this regard, bacteriophages and their enzymes, such as endolysins, are a very attractive alternative. Endolysins are the lytic enzymes, which are produced during the late phase of the lytic bacteriophage replication cycle to target the bacterial cell walls for progeny release. Here, we cloned, expressed, and purified LysZC1 endolysin from Pseudomonas phage ZCPS1. The structural alignment, molecular dynamic simulation, and CD studies suggested LysZC1 to be majorly helical, which is highly similar to various phage-encoded lysozymes with glycoside hydrolase activity. Our endpoint turbidity reduction assay displayed the lytic activity against various Gram-positive and Gram-negative pathogens. Although in synergism with EDTA, LysZC1 demonstrated significant activity against Gram-negative pathogens, it demonstrated the highest activity against Bacillus cereus. Moreover, LysZC1 was able to reduce the numbers of logarithmic-phase B. cereus by more than 2 log10 CFU/mL in 1 h and also acted on the stationary-phase culture. Remarkably, LysZC1 presented exceptional thermal stability, pH tolerance, and storage conditions, as it maintained the antibacterial activity against its host after nearly one year of storage at 4 °C and after being heated at temperatures as high as 100 °C for 10 min. Our data suggest that LysZC1 is a potential candidate as a therapeutic agent against bacterial infection and an antibacterial bio-control tool in food preservation technology.


Subject(s)
Bacteriophages , Pseudomonas Phages , Humans , Endopeptidases/genetics , Endopeptidases/pharmacology , Bacteriophages/genetics , Anti-Bacterial Agents/pharmacology
4.
J Appl Microbiol ; 133(3): 1597-1609, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35689810

ABSTRACT

AIMS: A novel endolysin Salmcide-p1 was developed as a promising candidate of new preservative and a supplement to effective enzyme preparations against gram-negative bacterial contaminations. METHODS AND RESULTS: Salmcide-p1 was identified by complementing the genomic sequence of a virulent Salmonella phage fmb-p1. Salmcide-p1 of 112 µg ml-1 could quickly kill Salmonella incubated with 100 mmol l-1 EDTA, with no haemolytic activity. Meanwhile, Salmcide-p1 had a high activity of lysing Salmonella cell wall peptidoglycan. At different temperatures (4-75°C), pH (4-11) and NaCl concentration (10-200 mmol l-1 ), the relative activity of Salmcide-p1 was above 60%. At 4°C, the combination of Salmcide-p1 and EDTA-2Na could inhibit the number of Salmonella Typhimurium CMCC 50115 in skim milk to less than 4 log CFU ml-1 by 3 days, and the number of Shigella flexneri CMCC 51571 was lower than 4 log CFU ml-1 by 9 days. CONCLUSIONS: Salmcide-p1 had a wide bactericidal activity against gram-negative bacteria and showed a broader anti-Salmonella spectrum than the phage fmb-p1. The combination strategy of Salmcide-p1 and EDTA-2Na could significantly inhibit the growth of gram-negative bacteria inoculated in skim milk. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacteriophage endolysin as an antibacterial agent is considered to be a new strategy against bacterial contamination.


Subject(s)
Bacteriophage P1 , Bacteriophages , Anti-Bacterial Agents/pharmacology , Bacteriophages/genetics , Edetic Acid/pharmacology , Endopeptidases/genetics , Endopeptidases/pharmacology , Gram-Negative Bacteria , Salmonella typhimurium/genetics
5.
Microbiol Spectr ; 10(1): e0146621, 2022 02 23.
Article in English | MEDLINE | ID: mdl-35196798

ABSTRACT

Bacterial pathogens are progressively adapting to current antimicrobial therapies with severe consequences for patients and global health care systems. This is critically underscored by the rise of methicillin resistant Staphylococcus aureus (MRSA) and other biofilm-forming staphylococci. Accordingly, alternative strategies have been explored to fight such highly multidrug resistant microorganisms, including antimicrobial photodynamic therapy (aPDT) and phage therapy. aPDT has the great advantage that it does not elicit resistance, while phage therapy allows targeting of specific pathogens. In the present study, we aimed to merge these benefits by conjugating the cell-binding domain (CBD3) of a Staphylococcus aureus phage endolysin to a photoactivatable silicon phthalocyanine (IRDye 700DX) for the development of a Staphylococcus-targeted aPDT approach. We show that, upon red-light activation, the resulting CBD3-700DX conjugate generates reactive oxygen species that effectively kill high loads of planktonic and biofilm-resident staphylococci, including MRSA. Furthermore, CBD3-700DX is readily internalized by mammalian cells, where it allows the targeted killing of intracellular MRSA upon photoactivation. Intriguingly, aPDT with CBD3-700DX also affects mammalian cells with internalized MRSA, but it has no detectable side effects on uninfected cells. Altogether, we conclude that CBD3 represents an attractive targeting agent for Staphylococcus-specific aPDT, irrespective of planktonic, biofilm-embedded, or intracellular states of the bacterium. IMPORTANCE Antimicrobial resistance is among the biggest threats to mankind today. There are two alternative antimicrobial therapies that may help to control multidrug-resistant bacteria. In phage therapy, natural antagonists of bacteria, lytic phages, are harnessed to fight pathogens. In antimicrobial photodynamic therapy (aPDT), a photosensitizer, molecular oxygen, and light are used to produce reactive oxygen species (ROS) that inflict lethal damage on pathogens. Since aPDT destroys multiple essential components in targeted pathogens, aPDT resistance is unlikely. However, the challenge in aPDT is to maximize target specificity and minimize collateral oxidative damage to host cells. We now present an antimicrobial approach that combines the best features of both alternative therapies, namely, the high target specificity of phages and the efficacy of aPDT. This is achieved by conjugating the specific cell-binding domain from a phage protein to a near-infrared photosensitizer. aPDT with the resulting conjugate shows high target specificity toward MRSA with minimal side effects.


Subject(s)
Anti-Bacterial Agents/pharmacology , Endopeptidases/pharmacology , Photochemotherapy , Staphylococcal Infections/microbiology , Staphylococcus Phages/chemistry , Staphylococcus/drug effects , Staphylococcus/physiology , Animals , Anti-Bacterial Agents/chemistry , Biofilms/drug effects , Drug Resistance, Multiple, Bacterial , Endopeptidases/chemistry , Endopeptidases/metabolism , Humans , Indoles/chemistry , Light , Organosilicon Compounds/chemistry , Photosensitizing Agents/chemistry , Reactive Oxygen Species/metabolism , Staphylococcal Infections/drug therapy , Staphylococcus/virology , Staphylococcus Phages/metabolism
6.
Virus Genes ; 56(4): 480-497, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32367411

ABSTRACT

Staphylococcus aureus is one of the most dreadful infectious agents, responsible for high mortality and morbidity in both humans and animals. The increased prevalence of multidrug-resistant (MDR) Staphylococcus aureus strains has limited the number of available treatment options, which calls for the development of alternative and effective modalities against MDR S. aureus. Endolysins are bacteriophage-derived antibacterials, which attack essential conserved elements of peptidoglycan that are vital for bacterial survival, making them promising alternatives or complements to existing antibiotics for tackling such infections. For developing endolysin lysin-methicillin-resistant-5 (LysMR-5) as an effective antimicrobial agent, we evaluated its physical and chemical characteristics, and its intrinsic antibacterial activity against staphylococcal strains, including methicillin-resistant Staphylococcus aureus (MRSA). In this study, we cloned, expressed, and purified LysMR-5 from S. aureus phage MR-5. In silico analysis revealed that LysMR-5 harbors two catalytic and one cell wall-binding domain. Biochemical characterization and LC-MS analysis showed that both catalytic domains were active and had no dependence on divalent ions for their action, Zn2+ exerted a negative effect. The optimal lytic activity of the endolysin was at 37 °C/pH 7.0 and in the presence of ≥ 300 mM concentration of NaCl. Circular dichroism (CD) demonstrated a loss in secondary structure with an increase in temperature confirming the thermosensitive nature of endolysin. Antibacterial assays revealed that LysMR-5 was active against diverse clinical isolates of staphylococci. It showed high lytic efficacy against S. aureus ATCC 43300, as an endolysin concentration as low as 15 µg/ml was sufficient to achieve maximum lytic activity within 30 min and it was further confirmed by scanning electron microscopy. Our results indicate that rapid and strong bactericidal activity of LysMR-5 makes it a valuable candidate for eradicating multidrug-resistant S. aureus.


Subject(s)
Endopeptidases/pharmacology , Staphylococcal Infections/drug therapy , Staphylococcus Phages/genetics , Animals , Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/therapeutic use , Humans , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Methicillin-Resistant Staphylococcus aureus/virology , Peptidoglycan/genetics , Staphylococcal Infections/microbiology
7.
Viruses ; 10(8)2018 08 18.
Article in English | MEDLINE | ID: mdl-30126174

ABSTRACT

Staphylococcus aureus is an important pathogen and biofilm former. Biofilms cause problems in clinics and food production and are highly recalcitrant to antibiotics and sanitizers. Bacteriophage endolysins kill bacteria by degrading their cell wall and are therefore deemed promising antimicrobials and anti-biofilm agents. Depolymerases targeting polysaccharides in the extracellular matrix have been suggested as parts of a multi-enzyme approach to eradicate biofilms. The efficacy of endolysins and depolymerases against S. aureus biofilms in static models has been demonstrated. However, there is a lack of studies evaluating their activity against biofilms grown under more realistic conditions. Here, we investigated the efficacy of the endolysin LysK and the poly-N-acetylglucosamine depolymerase DA7 against staphylococcal biofilms in static and dynamic (flow cell-based) models. LysK showed activity against multiple S. aureus strains, and both LysK and DA7 removed static and dynamic biofilms from polystyrene and glass surfaces at low micromolar and nanomolar concentrations, respectively. When combined, the enzymes acted synergistically, as demonstrated by crystal violet staining of static biofilms, significantly reducing viable cell counts compared to individual enzyme treatment in the dynamic model, and confocal laser scanning microscopy. Overall, our results suggest that LysK and DA7 are potent anti-biofilm agents, alone and in combination.


Subject(s)
Bacterial Adhesion/drug effects , Biofilms/drug effects , Endopeptidases/pharmacology , Glycoside Hydrolases/pharmacology , Staphylococcus aureus/drug effects , Bacteriophages/chemistry , Biofilms/growth & development , Drug Combinations , Drug Synergism , Endopeptidases/isolation & purification , Glass/chemistry , Glycoside Hydrolases/isolation & purification , Microbial Sensitivity Tests , Polystyrenes/chemistry , Rheology , Staphylococcus aureus/growth & development
8.
Int J Nanomedicine ; 13: 3625-3640, 2018.
Article in English | MEDLINE | ID: mdl-29983558

ABSTRACT

BACKGROUND: Lumbrokinase (LK) is an enzyme complex with antithrombotic, antioxidant, antitumor, and immunomodulatory effects. It has been extensively studied and used in clinical anti-tumor therapy. However, its half-life is short, its bioavailability is low, and its toxicity and side effects are great, which greatly limit its clinical application. Therefore, LK is often combined with other drugs (such as immune agents, hormones, or Chinese herbal medicine) to reduce its dosage and side effects and to improve its anti-tumor effects. METHODS AND RESULTS: Here, we described an LK/paclitaxel (PTX) nanocarrier based on poly(ethylene glycol)-b-(poly(ethylenediamine l-glutamate)-g-poly(ε-benzyoxycarbonyl-l-lysine)-r-poly(l-lysine)) (PEG-b-(PELG-g-(PZLL-r-PLL))). In the present study, LK and PTX were loaded by electrostatic and/or hydrophobic effects under mild conditions, thereby increasing the half-life and bioavailability of the drugs via the sustained release and enhancement of tumor site enrichment by the LK/PTX/PEG-b-(PELG-g-(PZLL-r-PLL)) complex through passive targeting. In this study, using bladder cancer cells (J82 cells) and rat bladder cancer model as the object, the structure of the nanocarrier, the relationship between drugs composition and antitumor properties were systematically studied. CONCLUSION: We propose that the block copolymer PEG-b-(PELG-g-(PZLL-r-PLL)) may function as a potent nanocarrier for augmenting anti-bladder cancer pharmacotherapy, with unprecedented clinical benefits.


Subject(s)
Albumins/therapeutic use , Endopeptidases/therapeutic use , Paclitaxel/therapeutic use , Urinary Bladder Neoplasms/drug therapy , Albumins/pharmacology , Animals , Apoptosis/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cyclin B1/metabolism , Drug Carriers/chemistry , Endopeptidases/blood , Endopeptidases/pharmacology , Humans , Hydrophobic and Hydrophilic Interactions , Lysine/analogs & derivatives , Lysine/chemical synthesis , Lysine/chemistry , Male , Microvessels/pathology , Molecular Weight , Paclitaxel/blood , Paclitaxel/pharmacology , Polyethylene Glycols/chemical synthesis , Polyethylene Glycols/chemistry , Polylysine/analogs & derivatives , Polylysine/chemical synthesis , Polylysine/chemistry , Rats, Sprague-Dawley , Tumor Burden/drug effects , Tumor Suppressor Protein p53/metabolism , Urinary Bladder Neoplasms/blood , Urinary Bladder Neoplasms/blood supply , Urinary Bladder Neoplasms/pathology
9.
Med Sci Monit Basic Res ; 23: 250-257, 2017 Jun 27.
Article in English | MEDLINE | ID: mdl-28652563

ABSTRACT

BACKGROUND Rifampin-soaked synthetic prosthetic grafts have been widely used for prevention or treatment of vascular graft infections (VGIs). This in vitro study investigated the effect of the antibiotics daptomycin and vancomycin and the new recombinant bacteriophage endolysin HY-133 on vascular cells, as potential alternatives compared to rifampin. MATERIAL AND METHODS Primary human ECs, vascular smooth muscle cells (vSMC), and fibroblasts were cultivated in 96-well plates and incubated with rifampin, daptomycin, vancomycin, and endolysin HY-133 for 24 h. Subsequently, after washing, cell viability was determined by measuring mitochondrial ATP concentration. Antibiotics were used in their corresponding minimum and maximum serum concentrations, in decimal multiples and in maximum soaking concentration. The experiments were performed in triplicate. RESULTS The 10-fold max serum concentrations of rifampin, daptomycin, and vancomycin did not influence viability of EC and vSMC (100 µg/ml, p>0.170). Higher concentrations of rifampin (>1 mg/ml) significantly (p<0.001) reduced cell viability of all cell types. For the other antibiotics, high concentrations (close to maximum soaking concentration) were most cytotoxic for EC and vSMC and fibroblasts (p<0.001). Endolysin did not display any cytotoxicity towards vascular cells. CONCLUSIONS Results of this in vitro study show the high cytotoxicity of rifampin against vascular cells, and may re-initiate the discussion about the benefit of prophylactic pre-soaking in high concentrations of rifampin. Further studies are necessary to determine the influence of rifampin on the restoration of vessel functionality versus its prophylactic effect against VGIs. Future use of recombinant phage endolysins for alternative prophylactic strategies needs further investigations.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Endothelial Cells/drug effects , Vascular Grafting/methods , Anti-Bacterial Agents/pharmacology , Cell Survival/drug effects , Daptomycin/pharmacology , Endopeptidases/pharmacology , Endothelial Cells/metabolism , Fibroblasts/drug effects , Fibroblasts/metabolism , Humans , Microbial Sensitivity Tests , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/metabolism , Rifampin/pharmacology , Vancomycin/pharmacology
10.
Curr Protein Pept Sci ; 18(8): 864-880, 2017.
Article in English | MEDLINE | ID: mdl-28393701

ABSTRACT

The aim of this review is to cover most recent research on plant pathogenesis- and defenserelated proteins from latex-bearing medicinal plant Chelidonium majus (Papaveraceae) in the context of its importance for latex activity, function, pharmacological activities, and antiviral medicinal use. These results are compared with other latex-bearing plant species and recent research on proteins and chemical compounds contained in their latex. This is the first review, which clearly summarizes pathogenesisrelated (PR) protein families in latex-bearing plants pointing into their possible functions. The possible antiviral function of the latex by naming the abundant proteins present therein is also emphasized. Finally latex-borne defense system is hypothesized to constitute a novel type of preformed immediate defense response against viral, but also non-viral pathogens, and herbivores.


Subject(s)
Antiviral Agents/chemistry , Chelidonium/chemistry , Latex/chemistry , Plant Proteins/chemistry , Alkaloids/chemistry , Alkaloids/isolation & purification , Alkaloids/pharmacology , Antiviral Agents/isolation & purification , Antiviral Agents/pharmacology , Benzylisoquinolines/chemistry , Benzylisoquinolines/isolation & purification , Benzylisoquinolines/pharmacology , Catechol Oxidase/chemistry , Catechol Oxidase/isolation & purification , Catechol Oxidase/pharmacology , Chitinases/chemistry , Chitinases/isolation & purification , Chitinases/pharmacology , Endopeptidases/chemistry , Endopeptidases/isolation & purification , Endopeptidases/pharmacology , Lipoxygenase/chemistry , Lipoxygenase/isolation & purification , Lipoxygenase/pharmacology , Peroxidases/chemistry , Peroxidases/isolation & purification , Peroxidases/pharmacology , Plant Proteins/isolation & purification , Plant Proteins/pharmacology , Ribonucleases/chemistry , Ribonucleases/isolation & purification , Ribonucleases/pharmacology , Virus Replication/drug effects
11.
Patol Fiziol Eksp Ter ; 60(3): 47-51, 2016.
Article in English | MEDLINE | ID: mdl-29244473

ABSTRACT

The purpose. Identifying the capacity of the medicinal leech novel original recombinant thrombolytic preparation Destabilase-Lysozyme-2 to inhibit the blood platelet aggregation. Methods: Gene of destabilase-lysozyme. ds2 (mlDL-Ds2 ), was cloned in E.coli cells. Recombinant protein was isolated in denaturing conditions using metal-chelate chromatography followed by denaturation of the polypeptide by rapid dilution in exact accordance with the procedure described by Kurdyumov A.S. et al. ( 2016, Russian Journal of Bioorganic Chemistry, v.42, s. 42-52). Blood was collected from the jugular vein of 18 horses. The functional status of platelets in the presence of different destabilase-lysozyme concentrations were evaluated for their aggregation in Platelet Rich Plasma ( PRP) and in Washed Platelet suspension (WP) using aggregometers Chrono-Log-700 and Сhrono-Log-560, USA560, США. As used aggregation inducers of ADP, collagen type III and human thrombin. Results: First demonstrated the ability of newly synthesized (Kurdyumov A.S. et al. 2016, Russian Journal of Bioorganic Chemistry, v42, s. 42-52) thrombolytic recombinant enzyme destabilase-lyzosyme to inhibit more than 40% of ADP-stimulated PRP aggregation and ADP- stimulated aggregation of horse blood washed platelets. Conclusion: The ability of destabilase-lyzosyme -2 to inhibit platelets aggregation extends biological properties of recombinant thrombolytic enzyme, pre-clinical trials which resulted in the end of 2015.


Subject(s)
Blood Platelets/metabolism , Endopeptidases , Fibrinolytic Agents , Hirudo medicinalis/enzymology , Muramidase , Platelet Aggregation/drug effects , Animals , Endopeptidases/chemistry , Endopeptidases/isolation & purification , Endopeptidases/pharmacology , Fibrinolytic Agents/chemistry , Fibrinolytic Agents/isolation & purification , Fibrinolytic Agents/pharmacology , Horses , Muramidase/chemistry , Muramidase/isolation & purification , Muramidase/pharmacology
12.
BMC Biochem ; 16: 27, 2015 Nov 21.
Article in English | MEDLINE | ID: mdl-26589324

ABSTRACT

BACKGROUND: Destabilase-Lysozyme (mlDL) is a multifunctional i-type enzyme that has been found in the secretions from the salivary glands of medicinal leeches. mlDL has been shown to exhibit isopeptidase, muramidase and antibacterial activity. This enzyme attracts interest because it expresses thrombolytic activity through isopeptidolysis of the ε-(γ-Glu)-Lys bonds that cross-link polypeptide chains in stabilised fibrin. To date, three isoforms of mlDL have been identified. The enzymatic properties of pure mlDL isoforms have not yet been described because only destabilase complexes containing other proteins could be isolated from the salivary gland secretion and because low product yield from the generation of recombinant proteins has made comprehensive testing difficult. RESULTS: In the present study, we optimised the procedures related to the expression, isolation and purification of active mlDL isoforms (mlDL-Ds1, mlDL-Ds2, mlDL-Ds3) using an Escherichia coli expression system, and we detected and compared their muramidase, lytic, isopeptidase and antimicrobial activities. After optimisation, the product yield was 30 mg per litre of culture. The data obtained in our study led to the suggestion that the recombinant mlDL isoforms isolated from inclusion bodies form stable oligomeric complexes. Analyses of the tested activities revealed that all isoforms exhibited almost identical patterns of pH and ionic strength effects on the activities. We determined that mlDL-Ds1, 2, 3 possessed non-enzymatic antibacterial activity independent of their muramidase activity. For the first time, we demonstrated the fibrinolytic activity of the recombinant mlDL and showed that only intact proteins possessed this activity, suggesting their enzymatic nature. CONCLUSIONS: The recombinant Destabilase-Lysozyme isoforms obtained in our study may be considered potential thrombolytic agents that act through a mechanism different from that of common thrombolytics.


Subject(s)
Endopeptidases/metabolism , Hirudo medicinalis/enzymology , Muramidase/metabolism , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/pharmacology , Bacillus subtilis/drug effects , Bacillus subtilis/growth & development , Chromatography, Affinity , Chromatography, Gel , Circular Dichroism , Drug Stability , Endopeptidases/genetics , Endopeptidases/isolation & purification , Endopeptidases/pharmacology , Enzyme Stability , Escherichia coli/drug effects , Escherichia coli/growth & development , Fibrinolytic Agents/isolation & purification , Fibrinolytic Agents/metabolism , Fibrinolytic Agents/pharmacology , Hydrogen-Ion Concentration , Isoenzymes/genetics , Isoenzymes/isolation & purification , Isoenzymes/metabolism , Isoenzymes/pharmacology , Microbial Sensitivity Tests , Muramidase/genetics , Muramidase/isolation & purification , Muramidase/pharmacology , Osmolar Concentration , Peptide Fragments/genetics , Peptide Fragments/isolation & purification , Peptide Fragments/metabolism , Peptide Fragments/pharmacology , Peptide Mapping , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Recombinant Proteins/pharmacology
13.
FEMS Microbiol Lett ; 362(24): fnv205, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26534896

ABSTRACT

Streptococcus suis serotype 2 (S. suis 2) is a zoonotic pathogen that exhibits high-level resistance and multi-drug resistance to classic antibiotics and causes serious human casualties and heavy economic losses in the swine industry worldwide. Therefore, alternative therapies or novel antibacterial agents need to be developed to combat this pathogen. A novel endolysin derived from the S. suis temperate phage phi7917, termed Ly7917, was identified, which had broad lytic activity against S. suis type 1, 2, 7 and 9. Ly7917 consisted of an N-terminal cysteine, histidine-dependent amidohydrolases/peptidase catalytic domain and C-terminal SH3b cell wall binding domain. The endolysin maintained activity at high pH and its catalytic activity could be improved by addition of 10 µM 1.5 mM Ca(2+). In animal studies, 90% of BALB/c mice challenged with typical virulent strain HA9801 of S. suis 2 were protected by Ly7917 treatment. The bacterial load in the blood of HA9801-challenged mice was efficiently reduced almost 50% by Ly7917 while that of penicillin-G-treated mice kept almost unchanged. Our data suggest that Ly7917 may be an alternative therapeutic agent for infections caused by virulent S. suis strains.


Subject(s)
Endopeptidases/metabolism , Endopeptidases/pharmacology , Streptococcus Phages/enzymology , Streptococcus suis/drug effects , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacterial Load/drug effects , Endopeptidases/chemistry , Endopeptidases/isolation & purification , Humans , Mice, Inbred BALB C , Microbial Sensitivity Tests , Penicillin G/therapeutic use , Prophages/enzymology , Streptococcal Infections/blood , Streptococcal Infections/drug therapy , Streptococcal Infections/microbiology , Streptococcus suis/ultrastructure , Streptococcus suis/virology
14.
PLoS One ; 10(7): e0132095, 2015.
Article in English | MEDLINE | ID: mdl-26167894

ABSTRACT

Endolysins, which are peptidoglycan-degrading enzymes expressed during the terminal stage of the reproduction cycle of bacteriophages, have great potential to control Gram-positive pathogens. This work describes the characterization of a novel endolysin (PlyPl23) encoded on the genome of Paenibacillus larvae phage phiIBB_Pl23 with high potential to control American foulbrood. This bacterial disease, caused by P. larvae, is widespread in North America and Europe and causes important economic losses in apiculture. The restriction to antibiotic residues in honey imposed by the EU legislation hinders its therapeutic use to combat American foulbrood and enforces the development of alternative antimicrobial methods. The new endolysin described herein has an N-acetylmuramoyl-L-alanine amidase catalytic domain and exhibits a broad-spectrum activity against common P. larvae genotypes. Moreover, the enzyme displays high antimicrobial activity in a range of pH that matches environmental conditions (pH between 5.0 and 7.0), showing its feasible application in the field. At pH 7.0, a concentration of 0.2 µM of enzyme was enough to lyse 104 CFU.mL-1 of P. larvae in no more than 2 h. The presence of sucrose and of the substances present in the larvae gut content did not affect the enzyme activity. Interestingly, an increase of activity was observed when PlyPl23 was previously incubated in royal jelly. Furthermore, in vivo safety evaluation assays demonstrated that this enzyme is not toxic to the bee larvae. The present work describes for the first time an endolysin encoded in a P. larvae phage that presents high potential to integrate a commercial product to control the problematic American foulbrood.


Subject(s)
Anti-Infective Agents/therapeutic use , Bacteriophages/physiology , Bees/microbiology , Endopeptidases/pharmacology , Gram-Positive Bacterial Infections/veterinary , Paenibacillus/virology , Animals , Endopeptidases/isolation & purification , Gram-Positive Bacterial Infections/drug therapy , Larva/microbiology , Microbial Sensitivity Tests , Paenibacillus/drug effects , Polymerase Chain Reaction , Spores, Bacterial/drug effects
15.
J Appl Microbiol ; 119(3): 620-31, 2015 09.
Article in English | MEDLINE | ID: mdl-26109320

ABSTRACT

Since their discovery in 1915, bacteriophages have been routinely used within Eastern Europe to treat a variety of bacterial infections. Although initially ignored by the West due to the success of antibiotics, increasing levels and diversity of antibiotic resistance is driving a renaissance for bacteriophage-derived therapy, which is in part due to the highly specific nature of bacteriophages as well as their relative abundance. This review focuses on the bacteriophages and derived lysins of relevant Gram-positive spore formers within the Bacillus cereus group and Clostridium genus that could have applications within the medical, food and environmental sectors.


Subject(s)
Bacteriophages/physiology , Biological Therapy , Endopeptidases/pharmacology , Gram-Positive Bacteria/drug effects , Gram-Positive Bacteria/virology , Gram-Positive Bacterial Infections/therapy , Spores, Bacterial/drug effects , Animals , Bacteriophages/chemistry , Endopeptidases/metabolism , Gram-Positive Bacteria/growth & development , Gram-Positive Bacteria/physiology , Gram-Positive Bacterial Infections/microbiology , Humans , Spores, Bacterial/growth & development
16.
Chin J Physiol ; 58(3): 188-96, 2015 Jun 30.
Article in English | MEDLINE | ID: mdl-26014124

ABSTRACT

Exposure to second-hand tobacco smoke (SHS) has been epidemiologically linked to heart disease among non-smokers. However, the molecular mechanism behind SHS-induced cardiac disease is not well known. This study found that SD rats exposed to cigarette smoke at a dose of 10 cigarettes for 30 min twice a day for 1 month had a reduced left ventricle-to-tibia length ratio (mg/mm), increased cardiomyocyte apoptosis by TUNEL assay and a wider interstitial space by H&E staining. However, lumbrokinase and dilong both reversed the effects of SHS. Western blotting demonstrated significantly increased expression of the pro-apoptotic protein caspase-3 in the hearts of the rats exposed to SHS. Elevated protein expression levels of Fas, FADD and the apoptotic initiator activated caspase-8, a molecule in the death-receptor-dependent pathway, coupled with increased t-Bid and apoptotic initiator activated caspase-9 were found. Molecules in the mitochondria-dependent pathway, which disrupts mitochondrial membrane potential, were also found in rats exposed to SHS. These factors indicate myocardial apoptosis. However, treatment with lumbrokinase and dilong inhibited SHS-induced apoptosis. Regarding regulation of the survival pathway, we found in western blot analysis that cardiac protein expression of pAkt, Bcl2, and Bcl-xL was significantly down-regulated in rats exposed to SHS. These effects were reversed with lumbrokinase and dilong treatment. The effects of SHS on cardiomyocytes were also found to be mediated by the Fas death receptor-dependent apoptotic pathway, an unbalanced mitochondria membrane potential and decreased survival signaling. However, treatment with both lumbrokinase and dilong inhibited the effects of SHS. Our data suggest that lumbrokinase and dilong may prevent heart disease in SHS-exposed non-smokers.


Subject(s)
Apoptosis/drug effects , Cardiotonic Agents/pharmacology , Endopeptidases/pharmacology , Medicine, Chinese Traditional , Myocytes, Cardiac/drug effects , Oligochaeta , Signal Transduction/drug effects , Tobacco Smoke Pollution/adverse effects , Animals , Caspase 3/metabolism , Male , Myocytes, Cardiac/pathology , Rats , Rats, Sprague-Dawley
17.
Am J Chin Med ; 43(2): 215-30, 2015.
Article in English | MEDLINE | ID: mdl-25787300

ABSTRACT

We assessed the therapeutic effects of lumbrokinase, a group of enzymes extracted from the earthworm, on peripheral-nerve regeneration using well-defined sciatic nerve lesion paradigms in diabetic rats induced by the injection of streptozotocin (STZ). We found that lumbrokinase therapy could improve the rats' circulatory blood flow and promote the regeneration of axons in a silicone rubber conduit after nerve transection. Lumbrokinase treatment could also improve the neuromuscular functions with better nerve conductive performances. Immunohistochemical staining showed that lumbrokinase could dramatically promote calcitonin gene-related peptide (CGRP) expression in the lamina I-II regions in the dorsal horn ipsilateral to the injury and cause a marked increase in the number of macrophages recruited within the distal nerve stumps. In addition, the lumbrokinase could stimulate the secretion of interleukin-1 (IL-1), nerve growth factor (NGF), platelet-derived growth factor (PDGF), and transforming growth factor-ß (TGF-ß) in dissected diabetic sciatic nerve segments. In conclusion, the administration of lumbrokinase after nerve repair surgery in diabetic rats was found to have remarkable effects on promoting peripheral nerve regeneration and functional recovery.


Subject(s)
Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/physiopathology , Endopeptidases/administration & dosage , Endopeptidases/pharmacology , Nerve Regeneration/drug effects , Sciatic Nerve/physiology , Administration, Oral , Animals , Blood Circulation/drug effects , Calcitonin Gene-Related Peptide/metabolism , Endopeptidases/isolation & purification , Interleukin-1/metabolism , Macrophages , Male , Nerve Growth Factor/metabolism , Neural Conduction/drug effects , Oligochaeta/enzymology , Platelet-Derived Growth Factor/metabolism , Rats, Sprague-Dawley , Sciatic Nerve/blood supply , Sciatic Nerve/metabolism , Streptozocin , Transforming Growth Factor beta/metabolism
18.
Am J Chin Med ; 42(6): 1507-19, 2014.
Article in English | MEDLINE | ID: mdl-25482676

ABSTRACT

Infusion of high-KCl cardioplegic solution (High-KCS) is the most common method used to induce asystole before cardiac surgery. However, our previous study showed the High-KCS can cause the apoptosis of cardiomyocytes in patients who were administered High-KCS prior to undergoing coronary artery bypass graft (CABG) to treat coronary artery disease (CAD). Therefore, it is urgent today to find a complementary medicine to reduce this damage. Dilong (earthworm) has been used as a traditional medicine in China for several thousand years, and extract from the dilong has been empirically used in Asia for the treatment of vascular disorders. In this study, we applied dilong extract to reduce myocardial cell damage from High-KCS infusion and further investigated the mechanisms. H9c2 cardiomyoblast cells were cultured in serum-free medium for 4 h and then treated with dilong at 31.25, 62.5, 125, and 250 mg/mL for 24 h, which was then followed by High-KCS treatment for 3 h to detect the protective mechanisms of dilong behind cardiomyocyte apoptosis and cardiac fibrosis. Cells were harvested for MTT assay, TUNEL assay, and western blot analysis. We found that High-KCS-induced cardiomyocyte apoptosis, enhanced the protein level of pro-apoptotic Bad, released cytochrome c, and activated caspase-3 in H9c2 cells. The IGF-I/IGF-IR/ERK pathway involved in non-cardiomyocyte proliferation, and the expression/activation of uPA, Sp-1 and CTGF, which are implicated in the development of cardiac fibrosis were up-regulated, but the Akt for cardiomyocyte survival was greatly deactivated in postcardioplegic H9c2 cardiomyoblast cells. However, dilong was highly protective and totally reversed the apoptosis and cardiac fibrosis effects induced by High-KCS. Chemical inhibitors P38 (SB203580), JNK (SP600125), MEK (U0126), IGF-1 (AG1024), and PI3K (LY294002) were applied to investigate which is the mediator for dilong attenuated High-KCS stimulated caspase 3 activation. MEK (U0126) inhibitor completely blocked dilong inhibited caspase 3 activation in High-KCS treated H9c2 cells. The MEK siRNA was further applied to knockdown MEK to confirm our finding. We found dilong worked through MEK to inhibit caspase 3 activity induced by High-KCS in H9c2 cells. Furthermore, we used the pure component of dilong, Lumbrokinase, to block the High-KCS effect. Using the microscope to observe the cell viability, we found Lumbrokinase could reverse the High-KCS effect. Lumbrokinase could also reduce the protein levels of caspase 8, caspase 9, and caspase 3, and enhance the survival related proteins PI3K/Akt and Bcl2. These results demonstrate that dilong could be used as a potential agent to block the side effects caused by High-KCS in CABG surgery patients.


Subject(s)
Apoptosis/drug effects , Cardioplegic Solutions/adverse effects , Endopeptidases/pharmacology , Mitogen-Activated Protein Kinase Kinases/physiology , Myocytes, Cardiac/pathology , Oligochaeta/chemistry , Potassium Chloride/adverse effects , Tissue Extracts/pharmacology , Animals , Apoptosis/genetics , Caspase 3/metabolism , Caspase 8/metabolism , Cells, Cultured , Coronary Artery Bypass , Dose-Response Relationship, Drug , Endopeptidases/isolation & purification , Fibrosis , Phosphatidylinositol 3-Kinases/metabolism , Rats , Time Factors , Tissue Extracts/isolation & purification
19.
Clin Immunol ; 153(2): 323-31, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24905137

ABSTRACT

Celiac disease (CD) is characterized by an inappropriate immunological reaction against gluten driven by gluten-specific CD4+ T cells. We screened 25 proteases and tested 10 for their potential to degrade gluten in vitro. Five proteases were further tested for their ability to prevent the proliferative response by a gluten-specific CD4+ T cell clone and seven gluten-reactive T cell lines to protease-digested gluten peptides. A proline-specific endo-peptidase from Aspergillus niger (AnP2) was particularly efficient at diminishing proliferation after stimulation with cleaved antigen, and could completely block the response against both native and deamidated gluten peptides. We found that AnP2 was efficient down to a 1:64 protease:substrate ratio (w:w). When AnP2 was tested in assays using seven gluten-reactive T cell lines from individual CD patients (three adults and four children), the response to gluten was diminished in all cases. Our study indicates a therapeutic benefit of AnP2 to CD patients.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Endopeptidases/immunology , Fungal Proteins/immunology , Glutens/immunology , Peptides/immunology , Adult , Amino Acid Sequence , Aspergillus niger/enzymology , CD4-Positive T-Lymphocytes/drug effects , Celiac Disease/immunology , Celiac Disease/pathology , Cell Line , Cell Proliferation/drug effects , Child , Clone Cells/drug effects , Clone Cells/immunology , Electrophoresis, Polyacrylamide Gel , Endopeptidases/metabolism , Endopeptidases/pharmacology , Fungal Proteins/metabolism , Fungal Proteins/pharmacology , Glutens/chemistry , Glutens/metabolism , Humans , Intestines/immunology , Molecular Sequence Data , Peptides/metabolism , Substrate Specificity
20.
Acta Haematol ; 132(2): 247-53, 2014.
Article in English | MEDLINE | ID: mdl-24862625

ABSTRACT

BACKGROUND/AIMS: Nattokinase is a serine protease produced by Bacillus subtilis during the fermentation of the soybean product natto. The fibrinolytic activity and thrombolytic effects of nattokinase have been observed in vitro, but the effect in vivo has still to be researched. The objective of this study was to demonstrate the activity of nattokinase in vivo. METHODS: To establish a rat model of thrombosis, κ-carrageenan was injected subcutaneously into the toes of Sprague-Dawley (SD) rats. Histological examination confirmed thrombosis. The rats were then treated with varying doses of nattokinase and the resulting thrombolysis was histologically assessed. ELISA was used to determine the levels of the fibrin/fibrinogen degradation products (FDPs) and D-dimer, which are sensitive indices of fibrinolytic activity. Vermis kinase, a known thrombolytic agent, was used as a positive control. RESULTS: Biopsy results revealed partial thrombolysis in the tail vessels of the rats treated with nattokinase or vermis kinase. FDP and D-dimer levels were higher in rats treated with high-dose nattokinase than in those treated with saline. No difference in FDP or D-dimer levels was observed between rats treated with high-dose nattokinase and those treated with vermis kinase. CONCLUSIONS: Both the histological and physiological evidence from this study indicate that nattokinase exerts thrombolytic effects in vivo.


Subject(s)
Fibrinolytic Agents/therapeutic use , Subtilisins/therapeutic use , Thrombosis/drug therapy , Animals , Carrageenan/toxicity , Drug Evaluation, Preclinical , Endopeptidases/pharmacology , Endopeptidases/therapeutic use , Female , Fibrin Fibrinogen Degradation Products/analysis , Fibrinolytic Agents/pharmacology , Random Allocation , Rats , Rats, Sprague-Dawley , Subtilisins/pharmacology , Thrombosis/chemically induced , Thrombosis/pathology
SELECTION OF CITATIONS
SEARCH DETAIL