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1.
Int J Biol Macromol ; 169: 39-50, 2021 Feb 01.
Article En | MEDLINE | ID: mdl-33316342

The Nocardiopsis alba strain OM-5 showed maximum protease production in submerged culture. The OM-5 protease was purified by hydrophobic interaction chromatography. The purified protease of 68 kDa showed maximum activity (3312 ± 1.64 U/mL) at 70 °C and was quite stable at 80 °C up to 4 M NaCl (w/v) at pH 9. The purified protease showed significant activity and stability in different cations, denaturing agents, metal ions, and osmolytes. The thermodynamic parameters including deactivation rate constant (Kd) and half lives (t1/2) at 50-80 °C were in the range of 2.50 × 10-3 to 5.50 × 10-3 and 277.25-111.25 min respectively at 0-4 M NaCl. The structural stability of the OM-5 protease under various harsh conditions was elucidated by circular dichroism (CD) spectroscopy followed by K2D3 analysis revealed that the native structure of OM-5 protease was stable even in sodium dodecyl sulfate and Tween 20 indicated by increased α-helices content assisted with decreased ß-sheets content.


Serine Endopeptidases/chemistry , Serine Endopeptidases/isolation & purification , Actinobacteria/chemistry , Bacterial Proteins/chemistry , Bacterial Proteins/isolation & purification , Detergents , Endopeptidases/chemistry , Endopeptidases/isolation & purification , Enzyme Stability/physiology , Hydrogen-Ion Concentration , Kinetics , Nocardiopsis/enzymology , Nocardiopsis/metabolism , Serine/chemistry , Serine Proteases/isolation & purification , Surface-Active Agents , Temperature , Thermodynamics
2.
Eur Biophys J ; 49(8): 773-779, 2020 Dec.
Article En | MEDLINE | ID: mdl-33057791

Reelin is a secreted glycoprotein that is integral in neocortex development and synaptic function. Reelin exists as a homodimer with two chains linked by a disulfide bond at cysteine 2101, a feature that is vital to the protein's function. This is highlighted by the fact that only dimeric Reelin can elicit efficient, canonical signaling, even though a mutated (C2101A) monomeric construct of Reelin retains the capacity to bind to its receptors. Receptor clustering has been shown to be important in the signaling pathway, however direct evidence regarding the stoichiometry of Reelin-receptor binding interaction is lacking. Here we describe the construction and purification of a heterodimeric Reelin construct to investigate the stoichiometry of Reelin-receptor binding and how it affects Reelin pathway signaling. We have devised different strategies and have finalized a protocol to produce a heterodimer of Reelin's central fragment using differential tagging and tandem affinity chromatography, such that chain A is wild type in amino acid sequence whereas chain B includes a receptor binding site mutation (K2467A). We also validate that the heterodimer is capable of binding to the extracellular domain of one of Reelin's known receptors, calculating the KD of the interaction. This heterodimeric construct will enable us to understand in greater detail the mechanism by which Reelin interacts with its known receptors and initiates pathway signaling.


Cell Adhesion Molecules, Neuronal/chemistry , Cell Adhesion Molecules, Neuronal/metabolism , Extracellular Matrix Proteins/chemistry , Extracellular Matrix Proteins/metabolism , Nerve Tissue Proteins/chemistry , Nerve Tissue Proteins/metabolism , Protein Multimerization , Serine Endopeptidases/chemistry , Serine Endopeptidases/metabolism , Cell Adhesion Molecules, Neuronal/isolation & purification , Extracellular Matrix Proteins/isolation & purification , HEK293 Cells , Humans , Nerve Tissue Proteins/isolation & purification , Neurons/cytology , Neurons/metabolism , Protein Binding , Protein Structure, Quaternary , Reelin Protein , Serine Endopeptidases/isolation & purification , Signal Transduction
3.
PDA J Pharm Sci Technol ; 74(5): 602-611, 2020.
Article En | MEDLINE | ID: mdl-32817324

Endotoxin testing by recombinant factor C (rFC) is increasing with the addition of new suppliers of reagents. By use of a recombinantly produced factor C , based on the sequence of a coagulation enzyme present in horseshoe crab amebocyte lysates, the rFC tests are designed as substitutes for the traditional Limulus amebocyte lysate (LAL)/Tachypleus amebocyte lysate tests based on horseshoe crab blood. Comparative testing of samples with both the LAL and recombinant reagents has shown a high degree of correlation, suggesting that use of rFC is comparable to the more traditional LAL tests and may be technologically superior. Recombinant factor C does not recognize the factor G pathway, the alternate coagulation pathway that the lysate reagents detect. This feature allows rFC to detect endotoxin more selectively. As a recombinantly produced material, it avoids the use of the horseshoe crabs required for lysate production, thereby protecting this species, which is at risk in some parts of the world. Recombinant factor C is expected to further benefit from a more sustainable supply chain based upon a robust biotechnological production process. We summarize here the results of many studies that evaluated the use of recombinant technology for the detection of environmental endotoxin. Additionally, we include a review of the current compendia and regulatory status of the recombinant technologies for use in the quality control of pharmaceutical manufacturing. Our analysis confirms that the recombinant technologies are comparable in protecting patient safety.


Arthropod Proteins/chemistry , Endotoxins/analysis , Enzyme Precursors/chemistry , Horseshoe Crabs/chemistry , Indicators and Reagents/chemistry , Limulus Test , Serine Endopeptidases/chemistry , Animals , Arthropod Proteins/isolation & purification , Enzyme Precursors/isolation & purification , Indicators and Reagents/isolation & purification , Reagent Kits, Diagnostic , Recombinant Proteins/chemistry , Reproducibility of Results , Serine Endopeptidases/isolation & purification
4.
J Vet Diagn Invest ; 32(5): 695-699, 2020 Sep.
Article En | MEDLINE | ID: mdl-32667260

Atypical porcine pestivirus (APPV) had been detected in many countries. However, to date, a commercial detection kit is not available because of a lack of specific monoclonal antibodies (mAbs) to APPV. We generated 7 mAbs targeting the NS3 protein of APPV. Isotyping results indicated that all of these mAbs are IgG1 with a kappa light chain. We analyzed the epitopes recognized by mAbs 2B6, 6G11, 8D1, 8D3, and 8F12, which recognized the same linear epitope (GRIKSAYSDE); the 6H3 and 7E10 mAbs recognized 2 different conformational epitopes. Applications of these antibodies were verified by ELISA, western blot, indirect immunofluorescence assay, and flow cytometry. The antibodies were functionally workable for these immunoassays except for 8F12, which could not be used in flow cytometry.


Antibodies, Monoclonal/isolation & purification , Antibodies, Viral/isolation & purification , Pestivirus Infections/veterinary , Pestivirus/immunology , Swine Diseases/immunology , Viral Nonstructural Proteins/isolation & purification , Animals , Pestivirus Infections/immunology , Pestivirus Infections/virology , RNA Helicases/isolation & purification , Serine Endopeptidases/isolation & purification , Sus scrofa , Swine , Swine Diseases/virology
5.
J Oleo Sci ; 69(3): 241-254, 2020.
Article En | MEDLINE | ID: mdl-32115548

Aspergillus terreus was chosen for production of alkaline protease using solid-state fermentation (SSF). The maximum enzyme yield reached about 34.87 U/mg protein after optimization of fermentation parameters. The produced alkaline protease was purified by precipitation with iso-propanol and then purified through gel filtration and ion exchange column chromatography with a yield of 53.58% and 5.09- fold purification. The enzyme has shown to have a molecular weight of 35 kDa. Optimal pH and temperature for the enzyme activity were 9.5 and 50°C respectively. The highest activity was reported towards casein, with an apparent Km value of 6.66 mg/mL and Vmax was 30 U/mL. The enzyme activity was greatly repressed by phenylmethylsulfonyl fluoride (PMSF). Sodium dodecyl sulfate (SDS) caused activation in enzyme activity. The enzyme retained about 83.8, 70.6, 74.5, 76.4 and 66.4% of its original activity after incubation with Aerial, Leader, Oxi, Persil and Tide, respectively for 8 h at 60°C. Adding of the enzyme in detergents improved the cleansing performance to the blood stains and suggested to be used as a detergent additive. Our outcomes showed that protease could be used as environment green-approach in dehairing process.


Aspergillus/metabolism , Detergents , Fermentation , Serine Endopeptidases , Enzyme Activation/drug effects , Hydrogen-Ion Concentration , Phenylmethylsulfonyl Fluoride/pharmacology , Serine Endopeptidases/isolation & purification , Serine Endopeptidases/metabolism , Sodium Dodecyl Sulfate/pharmacology , Temperature
6.
Int J Biol Macromol ; 151: 459-466, 2020 May 15.
Article En | MEDLINE | ID: mdl-32084472

Ecotin, a serine peptidase inhibitor (ISP), discovered in Escherichia coli, inhibit a wide range of trypsin-like serine peptidases, protecting microorganisms from the host's immune response. In eukaryotes, ISPs encoding genes were found only in Trypanosomatidae protozoa, including the genus Trypanosoma, which harbors Trypanosoma cruzi, the ethiological agent of Chagas' disease. T. cruzi encodes the ISP2 Trypanosomatidae orthologous, which in Leishmania species present inhibitory activity on mammalian proteases from S1A family suggesting its role in vertebrate-host-parasite interactions. In this study, the structural and biochemical characterization of the recombinant T. cruzi ISP2 (rTcISP2), produced in E. coli was purified in soluble form and analyzed by circular dichroism, fluorescence spectroscopy, native electrophoresis, dynamic light scattering, low X-ray scattering and homology modeling. The obtained data revealed that rTcISP2 was biologically active and forms homodimers in solution. Furthermore, inhibitory activity of rTcISP2 against human neutrophil elastase (HNE) is the highest among ISP2 orthologous from bacteria and trypanosomatids. The role of NE to control T. cruzi parasites through modulation of cellular and humoral innate immune responses in vertebrate hosts, make TcISP2 a key molecular component for parasite infection efficiency, providing a useful basis for investigation of host-parasite interactions and the potential of TcISP2 for biotechnological applications.


Serine Proteinase Inhibitors/chemistry , Serine Proteinase Inhibitors/pharmacology , Trypanocidal Agents/chemistry , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Amino Acid Sequence , Chagas Disease/drug therapy , Chagas Disease/parasitology , Enzyme Activation/drug effects , Gene Expression , Hydrogen-Ion Concentration , Recombinant Proteins , Serine Endopeptidases/chemistry , Serine Endopeptidases/genetics , Serine Endopeptidases/isolation & purification , Structure-Activity Relationship , Trypanosoma cruzi/enzymology , Trypanosoma cruzi/genetics
7.
Rapid Commun Mass Spectrom ; 34(2): e8573, 2020 Jan 30.
Article En | MEDLINE | ID: mdl-31484223

RATIONALE: Lys-N, also known as lysine-specific metalloendopeptidase, functions as the "sister" enzyme of lysyl endopeptidase (Lys-C) in proteomic research. Its digestion specificity at the N-terminal lysine residue makes it a very useful tool in proteomics analysis, especially in mass spectrometry (MS)-based de novo sequencing of proteins. METHODS: Here we present a complete production process of highly purified Lys-N from dry fruit of Grifola frondosa (maitake mushroom). The purification process includes one step of microfiltration plus one step of UF/DF (ultrafiltration used in tandem with a diafiltration method) recovery and four steps of chromatographic purification. RESULTS: The overall yield of the process was approximately 6.7 mg Lys-N protein/kg dry fruit of G. frondosa. The assay data demonstrated that the purified Lys-N exhibited high enzymatic activity and specificity. CONCLUSIONS: The novel production process provides for the first time the extraction of Lys-N from dry fruit of G. frondosa. The process is also stable and scalable, and provides an economic way of producing the enzyme in large quantities for MS-based proteomics and other biological studies.


Fruiting Bodies, Fungal/enzymology , Fungal Proteins/chemistry , Fungal Proteins/isolation & purification , Grifola/enzymology , Metalloendopeptidases/chemistry , Metalloendopeptidases/isolation & purification , Serine Endopeptidases/chemistry , Digestion , Fruiting Bodies, Fungal/chemistry , Grifola/chemistry , Proteomics , Serine Endopeptidases/isolation & purification
8.
Eur J Med Chem ; 184: 111746, 2019 Dec 15.
Article En | MEDLINE | ID: mdl-31610373

Presequence protease (PreP) is a proteostatic enzyme that plays a key role in the maintenance of mitochondrial health. Defects in PreP stability are associated with neurological disorders in humans, and altered activity of this enzyme modulates the progress of Alzheimer's disease-like pathology in mice. As agonists that boost PreP proteolytic activity represent a promising therapeutic avenue, we sought to determine the structural basis for the action of benzimidazole derivatives (3c and 4c), first reported by Vangavaragu et al. (Eur. J. Med. Chem. 76 (2014) 506-516) that enhance the activity of PreP. However, we found the published procedure for the synthesis of 3c yielded aldimine A instead. We then developed an alternative synthesis and obtained 3c, termed compound C, and an alternative benzimidazole derivative, termed compound B. We tested compounds A, B and C for their ability to enhance the activities of human PreP. In contrast to the previous report, we observed that none of the compounds A, B, or C (3c) modulated the catalytic activity of human PreP. Here we report our findings on the mis-identification of the reported benzimidazoles and the lack of biological activity of such compounds on human PreP. Thus, PreP modulators for PreP-based therapies remain to be discovered.


Benzimidazoles/pharmacology , Mitochondrial Proteins/metabolism , Serine Endopeptidases/metabolism , Small Molecule Libraries/pharmacology , Benzimidazoles/chemical synthesis , Benzimidazoles/chemistry , Dose-Response Relationship, Drug , Humans , Mitochondrial Proteins/genetics , Mitochondrial Proteins/isolation & purification , Molecular Structure , Serine Endopeptidases/genetics , Serine Endopeptidases/isolation & purification , Small Molecule Libraries/chemical synthesis , Small Molecule Libraries/chemistry , Structure-Activity Relationship
9.
Int J Biol Macromol ; 138: 528-535, 2019 Oct 01.
Article En | MEDLINE | ID: mdl-31323269

Subtilisins are a family of serine proteases used widely throughout the detergent, leather and food industries, with the identification and development of new enzymes holding much potential value. Thermus thermophilus HB8 was examined for serine proteases and found TTHA0724 gene. Sequence analysis of this putative serine protease placed it within the subtilisin family. To obtain active T. thermophilus HB8 subtilisins, three genes encoding prepro-subtilisin, pro-subtilisin and mature-subtilisin were cloned and expressed in Escherichia coli Transetta (DE3). Although direct expression of the mature-subtilisin gene was found to produce inactive inclusion bodies, expression of the pro-subtilisin gene resulted in active mature-subtilisin, indicating that the pro-sequence of translated pro-subtilisin underwent autoproteolysis. The resulting mature-subtilisin exhibited maximal activity between 65 and 85 °C at pH 7.5. The mature-subtilisin showed good stability, maintaining 50% activity after 48 h at 75 °C and >78% activity across the pH range 5.0-9.5. Furthermore, the mature-subtilisin demonstrated broad substrate specificity, with no requirement for the presence of metal ions which are essential for other subtilisin enzymes. Despite this Cu2+ was able to increase enzyme activity, while Ca2+ partially inhibited the activity. These properties suggest that T. thermophilus HB8 mature-subtilisin has potential value in its application in many industries.


Gene Expression , Recombinant Proteins , Serine Endopeptidases/genetics , Thermus thermophilus/genetics , Amino Acid Sequence , Computational Biology/methods , Enzyme Stability , Hydrogen-Ion Concentration , Hydrolysis , Ions/chemistry , Metals/chemistry , Models, Molecular , Mutation , Phylogeny , Protein Conformation , Serine Endopeptidases/chemistry , Serine Endopeptidases/isolation & purification , Substrate Specificity , Subtilisin/genetics , Thermus thermophilus/classification
10.
PLoS One ; 14(6): e0218346, 2019.
Article En | MEDLINE | ID: mdl-31246975

Gluten is a complex of proteins present in barley, wheat, rye and several varieties of oats that triggers celiac disease in genetically predisposed subjects. Gluten is notoriously difficult to digest by mammalian proteolytic enzymes and therefore, proline-rich digestion-resistant peptides contain multiple immunogenic epitopes. Prolyl endopeptidases (PEP) hydrolyse internal proline residues on the carboxyl side of peptides and have been proposed for food gluten detoxification and as oral enzyme supplementation for celiacs. The aim of this study was to identify new gluten-degrading microbial enzymes with the potential to reduce gluten immunogenicity by neutralizing its antigenic epitopes. Using a gluten-degrading colony screening approach, a bacterial isolate (2RA3) displaying the highest glutenase activity was selected, characterized and its genome completely sequenced. The identification through 16S rDNA gene sequencing showed a 99,1% similarity to Chryseobacterium taeanense. Hydrolysis of gluten immunogenic peptides (GIP) was further monitored, over a 48-hour period, by colony encapsulation in gliadin-containing microspheres, followed by detection with the G12 anti-GIP monoclonal antibody. Glutenase activity was detected in the extracellular medium of 2RA3 cultures, where gel electrophoresis and gliadin zymography revealed the presence of a ~50 kDa gluten-degrading enzyme. Nano-ESI-Q-TOF of the excised active band identified 7 peptides contained in the protein product predicted for an open reading frame (ORF) in the 2RA3 genome. Based on sequence similarity to the PEP family, the new enzyme was named PEP 2RA3. The PEP 2RA3 coding sequence was PCR-amplified from C. taeanense 2RA3, cloned and expressed in Escherichia coli as a C-terminally His-tagged recombinant protein and purified by Ni-NTA affinity chromatography. The recombinant protein, with predicted molecular mass and isoelectric point of 78.95 kDa and 6.8, respectively, shows PEP activity with standard chromogenic substrates, works optimally at pH 8.0 and 30°C and remains stable at pH 6.0 and 50°C, indicating a potential use in gluten-containing food process applications. The ability of the recombinant enzyme to degrade GIP in beer into smaller peptides was confirmed.


Glutens/metabolism , Serine Endopeptidases/administration & dosage , Serine Endopeptidases/metabolism , Amino Acid Sequence , Bacterial Proteins/administration & dosage , Bacterial Proteins/genetics , Bacterial Proteins/isolation & purification , Bacterial Proteins/metabolism , Celiac Disease/immunology , Celiac Disease/therapy , Chryseobacterium/genetics , Chryseobacterium/metabolism , Enzyme Activation , Gliadin/chemistry , Gliadin/immunology , Gliadin/metabolism , Glutens/chemistry , Glutens/immunology , Hydrolysis , Molecular Weight , Peptides/chemistry , Peptides/immunology , Peptides/metabolism , Prolyl Oligopeptidases , Recombinant Proteins/administration & dosage , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Serine Endopeptidases/genetics , Serine Endopeptidases/isolation & purification
11.
Gene ; 693: 10-15, 2019 Apr 20.
Article En | MEDLINE | ID: mdl-30690180

The use of proteases in the last decade has been welcomed in livestock and poultry industries and has led to significant results such as improved feed conversion ratio, weight gain and increased growth performance. In the present study, isolation and identification of a novel alkaline protease from Iranian Bacillus species was performed in order to use in livestock feed. After primary isolation of bacteria from soil samples of rice fields and early detection of bacterial genus, the zymogram plate was performed for evaluation of production extracellular proteases. Of the 11 strains producing protease, one strain that produced more enzymes was selected to continue the work. Characterization of alkaline protease was done using specific enzyme assays. To confirm the genus of isolates as well as to identify the species close to, molecular analysis of 16S rRNA gene sequence was done. After that, bioinformatics analysis carried out in NCBI database for searching bacterial alkaline proteases gene sequences. The primer designed based on gene homology of close species for extraction of alkaline protease gene. The results showed that the enzyme extract had the highest activity at pH 9.0 and 50 °C. The 16S rRNA gene sequence was submitted for the strain called Bacillus sp. RAM on the NCBI site. According to the results of the phylogenetic tree, the bacterium was belonged to Bacillus genus and Bacillus sp. RAM was close to Thuringiensis C405. The isolated alkaline protease gene successfully cloned in pET28a and transferred to the expression host E.coli BL21. The expression of the protease gene was evaluated by SDS-PAGE electrophoresis. The induced recombinant cells expressed the protease and revealed molecular weight band of about 38 kDa. According to the enzyme properties, this alkaline protease can useful for application in animal industry.


Bacterial Proteins/isolation & purification , Bacterial Proteins/metabolism , Endopeptidases/isolation & purification , Endopeptidases/metabolism , Amino Acid Sequence , Animal Feed/microbiology , Animals , Bacillus/genetics , Cloning, Molecular , Hydrogen-Ion Concentration , Iran , Livestock/genetics , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, RNA/methods , Serine Endopeptidases/isolation & purification , Serine Endopeptidases/metabolism , Temperature
12.
Mol Biol Rep ; 45(6): 1681-1689, 2018 Dec.
Article En | MEDLINE | ID: mdl-30168098

A novel feather-degrading bacterium named CA-1 was isolated from the gut of the spider Chilobrachys guangxiensis, which degrades native whole chicken feathers within 20 h. The CA-1 was confirmed to belong to Stenotrophomonas maltophilia based on morphologic and molecular analysis. Maximum feather degradation activity of the bacterium was observed at 37 °C in basal feather medium (NaCl 0.5 g/L, KH2PO4 0.3 g/L, K2HPO4 0.4 g/L, feather powder 10.0 g/L, pH 8.0), which was inhibited when glucose and ammonium nitrate were added in the medium. Furthermore, the purified enzymes under the optimal and suppressive conditions were analyzed respectively by SDS-PAGE and LC-MS/MS. Three enzymes, namely alkaline serine protease (29.1 kDa), ABC transporter permease (27.5 kDa), and alkaline phosphatase (40.8 kDa), were isolated and identified from the supernatant of the optimal culture and were considered to play principal roles. On the other hand, the potential synergic effects of the three proteins in S. maltophilia CA-1 feather degradation system were analyzed theoretically. CA-1 may product outer-membrane vesicles comprised of membranes and periplasmic proteins in the feather medium. The newly identified CA-1 and its synergic enzymes provide a new insight into further understanding the molecular mechanism of feather degradation by microbes. They also have potential application in cost-effectively degrading feathers into feeds and fertilizers through careful optimization and engineering of the three newly identified enzymes.


Feathers/enzymology , Stenotrophomonas maltophilia/enzymology , Stenotrophomonas maltophilia/metabolism , ATP-Binding Cassette Transporters/isolation & purification , ATP-Binding Cassette Transporters/metabolism , Alkaline Phosphatase/isolation & purification , Alkaline Phosphatase/metabolism , Animals , Bacteria/metabolism , Culture Media , Feathers/microbiology , Keratins/metabolism , Membrane Transport Proteins/isolation & purification , Membrane Transport Proteins/metabolism , Phylogeny , Proteolysis , Serine Endopeptidases/isolation & purification , Serine Endopeptidases/metabolism , Spiders/microbiology , Stenotrophomonas maltophilia/isolation & purification , Substrate Specificity
13.
Macromol Biosci ; 18(7): e1800095, 2018 07.
Article En | MEDLINE | ID: mdl-29870597

Herein, the synthesis of enzyme-polymer conjugates is reported. Four different activated polymers (mPEG-aldehyde, mPEG-NHS, maltodextrin-aldehyde, carboxymethyl cellulose aldehyde) are conjugated to the surface of protease, α-amylase, and lipase using two different strategies (reductive amination and alkylation with NHS-activated acid). Although the chemical modification of the enzymes is accompanied by losses in enzyme activity (maximum loss 40%), the covalent attachment of polymers increases the thermal stability and the stability in a standard detergent formulation compared to the unmodified enzymes. The enzyme-polymer conjugates are characterized by asymmetrical-flow field-flow fractionation and differential scanning microcalorimetry. Furthermore, it is demonstrated that conjugated enzymes still show performance in a real washing process. Enzyme-polymer conjugates show a potential as a stabilizing system for enzymes in detergents.


Aldehydes/chemistry , Enzymes, Immobilized/chemistry , Lipase/chemistry , Polyethylene Glycols/chemistry , Serine Endopeptidases/chemistry , alpha-Amylases/chemistry , Alkylation , Amination , Bacillus licheniformis/chemistry , Bacillus licheniformis/enzymology , Bacillus subtilis/chemistry , Bacillus subtilis/enzymology , Carboxymethylcellulose Sodium/chemistry , Detergents/chemistry , Enzyme Assays , Enzyme Stability , Enzymes, Immobilized/isolation & purification , Kinetics , Lipase/isolation & purification , Polysaccharides/chemistry , Saccharomycetales/chemistry , Saccharomycetales/enzymology , Serine Endopeptidases/isolation & purification , Succinimides/chemistry , Thermodynamics , alpha-Amylases/isolation & purification
14.
Int J Biol Macromol ; 114: 788-811, 2018 Jul 15.
Article En | MEDLINE | ID: mdl-29604354

Snake venom thrombin-like enzymes (SVTLEs) constitute the major portion (10-24%) of snake venom and these are the second most abundant enzymes present in the crude venom. During envenomation, these enzymes had shown prominently the various pathological effects, such as disturbance in hemostatic system, fibrinogenolysis, fibrinolysis, platelet aggregation, thrombosis, neurologic disorders, activation of coagulation factors, coagulant, procoagulant etc. These enzymes also been used as a therapeutic agent for the treatment of various diseases such as congestive heart failure, ischemic stroke, thrombotic disorders etc. Although the crystal structures of five SVTLEs are available in the Protein Data Bank (PDB), there is no single article present in the literature that has described all of them. The current work describes the structural aspects, structure-based mechanism of action, processing and inhibition of these enzymes. The sequence analysis indicates that these enzymes show a high sequence identity (57-85%) with each other and low sequence identity with trypsin (36-43%), human alpha-thrombin (29-36%) and other snake venom serine proteinases (57-85%). Three-dimensional structural analysis indicates that the loops surrounding the active site are variable both in amino acids composition and length that may convey variable substrate specificity to these enzymes. The surface charge distributions also vary in these enzymes. Docking analysis with suramin shows that this inhibitor preferably binds to the C-terminal region of these enzymes and causes the destabilization of their three-dimensional structure.


Serine Endopeptidases/isolation & purification , Snake Venoms/enzymology , Amino Acid Sequence , Animals , Catalysis , Enzyme Precursors/chemistry , Glycosylation , Humans , Models, Molecular , Protein Conformation , Protein Processing, Post-Translational , Sequence Alignment , Sequence Homology, Amino Acid , Serine Endopeptidases/chemistry , Serine Proteinase Inhibitors/pharmacology , Structure-Activity Relationship , Substrate Specificity , Suramin/pharmacology , Thrombin/chemistry
15.
Int J Biol Macromol ; 109: 1039-1044, 2018 Apr 01.
Article En | MEDLINE | ID: mdl-29155158

The thermostable crude proteolytic extract and purified protease produced by Aspergillus tamarii URM4634 were investigated at different temperatures. The activity results were used to estimate the activation energy of the hydrolysis reaction catalyzed by crude extract and purified protease (E*=34.2 and 16.2kJ/mol) as well as the respective standard enthalpy variations of reversible enzyme unfolding (ΔH°u=31.9 and 13.9kJ/mol). When temperature was raised from 50 to 80°C in residual activity tests, the specific rate constant of crude proteolytic extract thermoinactivation increased from 0.0072 to 0.0378min-1, while that of purified protease from 0.0099 to 0.0235min-1. These values, corresponding to half-life decreases from 96.3 to 18.3min and from 70.0 to 29.5min, respectively, enabled us to estimate the activation energy (E*d=49.7 and 28.8kJ/mol), enthalpy (ΔH*d=47.0 and 26.1kJ/mol), entropy (ΔS*d=-141.3 and -203.1J/molK) and Gibbs free energy (92.6≤ΔG*d≤96.6kJ/mol and 91.8≤ΔG*d≤98.0kJ/mol) of thermoinactivation. Such values suggest that this protease, which proved to be highly thermostable in both forms, could be profitably exploited in industrial applications. To the best of our knowledge, this is the first comparative study on thermodynamic parameters of a serine protease produced by Aspergillus tamarii URM4634.


Aspergillus/enzymology , Serine Endopeptidases/chemistry , Serine Endopeptidases/metabolism , Thermodynamics , Chromatography, Ion Exchange , Enzyme Activation , Enzyme Stability , Kinetics , Serine Endopeptidases/isolation & purification
16.
Int J Biol Macromol ; 109: 992-1005, 2018 Apr 01.
Article En | MEDLINE | ID: mdl-29155201

The HtrA proteins due to their proteolytic, and in many cases chaperone activity, efficiently counteract consequences of stressful conditions. In the environmental bacterium and nosocomial pathogen Stenotrophomonas maltophilia HtrA (HtrASm) is induced as a part of adaptive response to host temperature (37°C). We examined the biochemical properties of HtrASm and compared them with those of model HtrAEc from Escherichia coli. We found that HtrASm is a protease and chaperone that operates over a wide range of pH and is highly active at temperatures between 35 and 37°C. The temperature-sensitive activity corresponded well with the lower thermal stability of the protein and weaker stability of the oligomer. Interestingly, the enzyme shows slightly different substrate cleavage specificity when compared to other bacterial HtrAs. A computational model of the three-dimensional structure of HtrASm indicates differences in the S1 substrate specificity pocket and suggests weaker inter-trimer interactions when compared to HtrAEc. The observed features of HtrASm suggest that this protein may play a protective role under stressful conditions acting both as a protease and a chaperone. The optimal temperatures for the protein activity may reflect the evolutionary adaptation of S. maltophilia to life in soil or aqueous environments, where the temperatures are usually much below 37°C.


Bacterial Proteins/chemistry , Biochemical Phenomena , Serine Endopeptidases/chemistry , Stenotrophomonas maltophilia/enzymology , Amino Acid Sequence , Bacterial Proteins/metabolism , Computational Biology , Enzyme Activation , Enzyme Stability , Models, Molecular , Molecular Chaperones/chemistry , Molecular Chaperones/metabolism , Protein Binding , Protein Conformation , Protein Multimerization , Proteolysis , Serine Endopeptidases/isolation & purification , Serine Endopeptidases/metabolism , Substrate Specificity
17.
Food Chem ; 245: 1169-1175, 2018 Apr 15.
Article En | MEDLINE | ID: mdl-29287337

This work describes purification of a protease from the visceral mass of the mussel Mytella charruana as well as evaluation of its ability to hydrolyze milk casein to generate antimicrobial peptides. The enzyme showed pI of 4.1 and a single polypeptide band of 83.1 kDa after SDS-PAGE. Sequence similarities with tropomyosin and myosin from mollusks were detected. The protease showed a trypsin-like activity with optimal temperature of 40 °C and stability in a wide pH range (3.0-9.0). Km was 4.28 ±â€¯0.34 mM of the synthetic substrate N-benzoyl-dl-arginyl-ρ-nitroanilide, whereas Vmax was 0.056 ±â€¯0.001 nmol min-1. The enzyme hydrolyzed casein, and the hydrolysate inhibited the growth of Escherichia coli, Micrococcus luteus, Bacillus subtilis, and Klebsiella pneumoniae at a minimal inhibitory concentration of 5.0 µg mL-1. In conclusion, the visceral mass of M. charruana contains a trypsin-like protease that can generate peptides from casein that have a bacteriostatic effect.


Anti-Bacterial Agents/pharmacology , Antifungal Agents/pharmacology , Bivalvia/enzymology , Peptides/pharmacology , Serine Endopeptidases/metabolism , Animals , Anti-Bacterial Agents/chemistry , Antifungal Agents/chemistry , Caseins/chemistry , Caseins/metabolism , Drug Evaluation, Preclinical/methods , Electrophoresis, Polyacrylamide Gel , Enzyme Stability , Hydrogen-Ion Concentration , Hydrolysis , Microbial Sensitivity Tests , Peptides/chemistry , Peptides/metabolism , Serine Endopeptidases/isolation & purification , Temperature , Viscera/enzymology
18.
PLoS One ; 12(11): e0188170, 2017.
Article En | MEDLINE | ID: mdl-29161301

BACKGROUND: The traditional methods, plaque assays and immuno-focus assays, used to titrate infectious dengue virus (DENV) particles are time consuming and labor intensive. Here, we developed a DENV protease activity detection system (DENPADS) to visualize DENV infection in cells based on dengue protease activity. METHODOLOGY/PRINCIPAL FINDINGS: Dengue NS3 protease cleaves NS4B-NS5. BHK-21 cells stably expressing the sensor module comprising DENV-2 NS4 and the 10 amino-terminal amino acids of NS5 (N10NS5) fused with the SV40 nuclear localization signal (NLS) and Cre recombinase (Cre), were generated. Cre is constrained outside the nucleus in the absence of NS3 activity but translocates into the nucleus through NS4B-NS5 cleavage when cells are infected with DENV. Nuclear translocation of Cre can trigger the reporter system, which contains a cis-loxP-flanked mCherry with three continuous stop codons following an SV40 polyA tail cDNA upstream of EGFP or mHRP cDNA. Our results show that DENPADS is an efficient and accurate method to titrate 4 DENV serotypes in 24 hours. Compared with current virus titration methods, the entire process is easy to perform, and the data are easily acquired. CONCLUSIONS/SIGNIFICANCE: In this study, we demonstrate that DENPADS can be used to detect dengue viral infection through a fluorescence switch or HRP activity in the infected cells. This approach is sensitive with less incubation time and labor input. In addition, DENPADS can simultaneously evaluate the efficacy and cytotoxicity of potential anti-DENV candidates. Overall, DENPADS is a useful tool for dengue research.


Biosensing Techniques , Dengue Virus/isolation & purification , Dengue/diagnosis , Serine Endopeptidases/isolation & purification , Dengue/enzymology , Dengue/virology , Dengue Virus/pathogenicity , Humans , Serine Endopeptidases/genetics , Serogroup , Virus Replication
19.
Biomed Res Int ; 2017: 4825108, 2017.
Article En | MEDLINE | ID: mdl-28890895

The current study is to develop a gentle and efficient method for purification of fibroblast-activation protein positive (FAP+) cancer-associated fibroblasts (CAFs) from tumor tissues. Fresh tissues were isolated from BALB/c-Nude mice bearing human liver cancer cell line (HepG2), fully minced and separated into three parts, and digested with trypsin digestion and then treated with collagenase type IV once, twice, or thrice, respectively. Finally, the cells were purified by using FAP magnetic beads. The isolated CAFs were grown in culture medium and detected for the surface expression of fibroblast-activation protein (FAP). The number of adherent cells which were obtained by digestion process with twice collagenase type IV digestion was (5.99 ± 0.18) × 104, much more than that with the only once collagenase type IV digestion (2.58 ± 0.41) × 104 (P < 0.0001) and similar to thrice collagenase type IV digestion. The percentage of FAP+ CAFs with twice collagenase type IV digestion (38.5%) was higher than that with the only once collagenase type IV digestion (20.0%) and little higher than thrice collagenase type IV digestion (37.5%). The FAP expression of CAFs was quite different from normal fibroblasts (NFs). The fibroblasts isolated by the innovation are with high purity and being in wonderful condition and display the features of CAFs.


Cancer-Associated Fibroblasts/enzymology , Collagenases/genetics , Gelatinases/genetics , Membrane Proteins/genetics , Neoplasms/enzymology , Neoplasms/genetics , Serine Endopeptidases/genetics , Animals , Collagenases/metabolism , Endopeptidases , Gelatinases/isolation & purification , Gelatinases/metabolism , Gene Expression Regulation, Neoplastic , Hep G2 Cells , Humans , Membrane Proteins/isolation & purification , Membrane Proteins/metabolism , Mice , Neoplasms/embryology , Neoplasms/pathology , Serine Endopeptidases/isolation & purification , Serine Endopeptidases/metabolism
20.
Sci Rep ; 7(1): 9147, 2017 08 22.
Article En | MEDLINE | ID: mdl-28831173

Fungi are able to switch between different lifestyles in order to adapt to environmental changes. Their ecological strategy is connected to their secretome as fungi obtain nutrients by secreting hydrolytic enzymes to their surrounding and acquiring the digested molecules. We focus on fungal serine proteases (SPs), the phylogenetic distribution of which is barely described so far. In order to collect a complete set of fungal proteases, we searched over 600 fungal proteomes. Obtained results suggest that serine proteases are more ubiquitous than expected. From 54 SP families described in MEROPS Peptidase Database, 21 are present in fungi. Interestingly, 14 of them are also present in Metazoa and Viridiplantae - this suggests that, except one (S64), all fungal SP families evolved before plants and fungi diverged. Most representatives of sequenced eukaryotic lineages encode a set of 13-16 SP families. The number of SPs from each family varies among the analysed taxa. The most abundant are S8 proteases. In order to verify hypotheses linking lifestyle and expansions of particular SP, we performed statistical analyses and revealed previously undescribed associations. Here, we present a comprehensive evolutionary history of fungal SP families in the context of fungal ecology and fungal tree of life.


Fungi/classification , Serine Endopeptidases/classification , Evolution, Molecular , Fungal Proteins/classification , Fungal Proteins/isolation & purification , Fungi/enzymology , Multigene Family , Phylogeny , Sequence Homology, Amino Acid , Serine Endopeptidases/isolation & purification
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