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1.
J Proteome Res ; 19(8): 3467-3477, 2020 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-32597192

RESUMEN

Cryptic peptides (cryptides) are biologically active peptides formed after proteolysis of native precursors present in animal venoms, for example. Proteolysis is an overlooked post-translational modification that increases venom complexity. The tripeptide KPP (Lys-Pro-Pro) is a peptide encrypted in the C-terminus of Ts14-a 25-mer peptide from the venom of the Tityus serrulatus scorpion that has a positive impact on the cardiovascular system, inducing vasodilation and reducing arterial blood pressure of hypertensive rats among other beneficial effects. A previous study reported that KPP and its native peptide Ts14 act via activation of the bradykinin receptor B2 (B2R). However, the cellular events underlying the activation of B2R by KPP are unknown. To study the cell signaling triggered by the Ts14 cryptide KPP, we incubated cardiac myocytes isolated from C57BL/6 mice with KPP (10-7 mol·L-1) for 0, 5, or 30 min and explored the proteome and phosphoproteome. Our results showed that KPP regulated cardiomyocyte proteins associated with, but not limited to, apoptosis, muscle contraction, protein turnover, and the respiratory chain. We also reported that KPP led to AKT phosphorylation, activating AKT and its downstream target nitric oxide synthase. We also observed that KPP led to dephosphorylation of phospholamban (PLN) at its activation sites (S16 and T17), leading to reduced contractility of treated cardiomyocytes. Some cellular targets reported here for KPP (e.g., AKT, PLN, and ERK) have already been reported to protect the cardiac tissue from hypoxia-induced injury. Hence, this study suggests potential beneficial effects of this scorpion cryptide that needs to be further investigated, for example, as a drug lead for cardiac infarction.


Asunto(s)
Venenos de Escorpión , Animales , Proteínas de Unión al Calcio , Ratones , Ratones Endogámicos C57BL , Miocitos Cardíacos , Péptidos/farmacología , Proteínas Proto-Oncogénicas c-akt , Ratas , Venenos de Escorpión/farmacología , Transducción de Señal
2.
Amino Acids ; 51(3): 433-449, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30449002

RESUMEN

Antimicrobial peptides present a broad spectrum of therapeutic applications, including their use as anticancer peptides. These peptides have as target microbial, normal, and cancerous cells. The oncological properties of these peptides may occur by membranolytic mechanisms or non-membranolytics. In this work, we demonstrate for the first time the cytotoxic effects of the cationic alpha-helical antimicrobial peptide LyeTx I-b on glioblastoma lineage U87-MG. The anticancer property of this peptide was associated with a membranolytic mechanism. Loss of membrane integrity occurred after incubation with the peptide for 15 min, as shown by trypan blue uptake, reduction of calcein-AM conversion, and LDH release. Morphological studies using scanning electron microscopy demonstrated disruption of the plasma membrane from cells treated with LyeTx I-b, including the formation of holes or pores. Transmission electron microscopy analyses showed swollen nuclei with mild DNA condensation, cell volume increase with an electron-lucent cytoplasm and organelle vacuolization, but without the rupture of nuclear or plasmatic membranes. Morphometric analyses revealed a high percentage of cells in necroptosis stages, followed by necrosis and apoptosis at lower levels. Necrostatin-1, a known inhibitor of necroptosis, partially protected the cells from the toxicity of the peptide in a concentration-dependent manner. Imaging flow cytometry confirmed that 59% of the cells underwent necroptosis after 3-h incubation with the peptide. It is noteworthy that LyeTx I-b showed only mild cytotoxicity against normal fibroblasts of human and monkey cell lines and low hemolytic activity in human erythrocytes. All data together point out the anticancer potential of this peptide.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/farmacología , Apoptosis/efectos de los fármacos , Fibroblastos/patología , Glioblastoma/patología , Neuroblastoma/patología , Venenos de Araña/farmacología , Arañas/química , Animales , Autofagia , Permeabilidad de la Membrana Celular , Células Cultivadas , Fibroblastos/efectos de los fármacos , Glioblastoma/tratamiento farmacológico , Hemólisis/efectos de los fármacos , Humanos , Necrosis , Neuroblastoma/tratamiento farmacológico
4.
Genet Mol Biol ; 38(2): 227-30, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26273227

RESUMEN

Several studies of the physiological responses of different organisms exposed to extremely low-frequency electromagnetic fields (ELF-EMF) have been described. In this work, we report the minimal effects of in situ exposure to ELF-EMF on the global protein expression of Chromobacterium violaceum using a gel-based proteomic approach. The protein expression profile was only slightly altered, with five differentially expressed proteins detected in the exposed cultures; two of these proteins (DNA-binding stress protein, Dps, and alcohol dehydrogenase) were identified by MS/MS. The enhanced expression of Dps possibly helped to prevent physical damage to DNA. Although small, the changes in protein expression observed here were probably beneficial in helping the bacteria to adapt to the stress generated by the electromagnetic field.

5.
BMC Genomics ; 15: 986, 2014 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-25407400

RESUMEN

BACKGROUND: Exiguobacterium antarcticum strain B7 is a Gram-positive psychrotrophic bacterial species isolated in Antarctica. Although this bacteria has been poorly studied, its genome has already been sequenced. Therefore, it is an appropriate model for the study of thermal adaptation. In the present study, we analyzed the transcriptomes and proteomes of E. antarcticum B7 grown at 0°C and 37°C by SOLiD RNA-Seq, Ion Torrent RNA-Seq and two-dimensional difference gel electrophoresis tandem mass spectrometry (2D-DIGE-MS/MS). RESULTS: We found expression of 2,058 transcripts in all replicates from both platforms and differential expression of 564 genes (absolute log2FC≥1, P-value<0.001) comparing the two temperatures by RNA-Seq. A total of 73 spots were differentially expressed between the two temperatures on 2D-DIGE, 25 of which were identified by MS/MS. Some proteins exhibited patterns of dispersion in the gel that are characteristic of post-translational modifications. CONCLUSIONS: Our findings suggest that the two sequencing platforms yielded similar results and that different omic approaches may be used to improve the understanding of gene expression. To adapt to low temperatures, E. antarcticum B7 expresses four of the six cold-shock proteins present in its genome. The cold-shock proteins were the most abundant in the bacterial proteome at 0°C. Some of the differentially expressed genes are required to preserve transcription and translation, while others encode proteins that contribute to the maintenance of the intracellular environment and appropriate protein folding. The results denote the complexity intrinsic to the adaptation of psychrotrophic organisms to cold environments and are based on two omic approaches. They also unveil the lifestyle of a bacterial species isolated in Antarctica.


Asunto(s)
Adaptación Fisiológica/genética , Bacillaceae/genética , Bacillaceae/fisiología , Frío , Regulación Bacteriana de la Expresión Génica , Genómica/métodos , Bacillaceae/crecimiento & desarrollo , Membrana Celular/metabolismo , Proteínas y Péptidos de Choque por Frío/metabolismo , Electroforesis en Gel Bidimensional , Perfilación de la Expresión Génica , Espectrometría de Masas , Biosíntesis de Proteínas , Pliegue de Proteína , Proteoma/metabolismo , Análisis de Secuencia de ARN , Transcripción Genética
6.
J Proteome Res ; 12(7): 3460-70, 2013 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-23731212

RESUMEN

Besides being a public health problem, scorpion venoms have a potential biotechnological application since they contain peptides that may be used as drug leads and/or to reveal novel pharmacological targets. A comprehensive Tityus serrulatus venom proteome study with emphasis on the phosphoproteome and N-glycoproteome was performed to improve our knowledge on the molecular diversity of the proteinaceous toxins. We combined two peptide identification methodologies, i.e., database search and de novo sequencing, to achieve a more comprehensive overview of the molecular diversity of the venoms. A total of 147 proteins were identified, including neurotoxins, enzymes, bradykinin-potentiating peptides, and molecules with antimicrobial and diuretic activities. Among those, three proteins were found to be phosphorylated, and one N-glycosylated. Finally, cleavage of toxin polypeptide chains seems to be a common post-translational modification in the venom since 80% of the identified molecules were, in fact, products of toxins proteolysis.


Asunto(s)
Glicoproteínas/aislamiento & purificación , Fosfoproteínas/aislamiento & purificación , Proteoma/metabolismo , Venenos de Escorpión/metabolismo , Secuencia de Aminoácidos , Animales , Glicoproteínas/clasificación , Neurotoxinas/metabolismo , Fosfoproteínas/clasificación , Escorpiones/metabolismo
7.
Microb Pathog ; 61-62: 37-42, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23684727

RESUMEN

This study involves the comparison between the exoproteomes of two different strains of Corynebacterium pseudotuberculosis, the etiologic agent of caseous lymphadenitis in small ruminants. In a previous study, based on a gel-free system (TPP-LC/MS(E)), 70 exoproteins for the strain 1002 and 67 for the strain C231, totaling 93 different extracellular proteins for C. pseudotuberculosis, were identified. In the present work, we have used 2D gel electrophoresis to resolve the extracellular proteins of both strains, which were then digested with trypsin, analyzed by MALDI-TOF/TOF and identified with the software MASCOT(®). A total of 45 extracellular proteins of C. pseudotuberculosis were identified by this approach. The comparative analysis between the strains 1002 and C231 identified 13 and 3 strain-specific proteins, respectively, 11 of which are novel. These newly identified proteins may play an important role in the physiology and virulence of C. pseudotuberculosis.


Asunto(s)
Proteínas Bacterianas/análisis , Corynebacterium pseudotuberculosis/química , Corynebacterium pseudotuberculosis/clasificación , Proteoma , Animales , Proteínas Bacterianas/química , Infecciones por Corynebacterium/microbiología , Infecciones por Corynebacterium/veterinaria , Electroforesis en Gel Bidimensional/métodos , Linfadenitis/microbiología , Linfadenitis/veterinaria , Proteómica/métodos , Especificidad de la Especie , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos
8.
Curr Microbiol ; 67(4): 460-5, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23699973

RESUMEN

Corynebacterium pseudotuberculosis is the etiologic agent of caseous lymphadenitis a chronic infectious disease affecting small ruminants. The 2D-DIGE technique was used to compare the exoproteomes of two C. pseudotuberculosis biovar ovis strains isolated from goat (strain 1002) and sheep (strain C231). Seventeen proteins differentially produced were identified here. Nine proteins appeared over-produced in the exoproteome of 1002 goat strain and 8 in that of C231 sheep strain. These proteins were related to various biological functions, such as the cell envelope, respiratory metabolism and proteolysis. This proteomic analysis revealed strain-specific exoproteins although each of the corresponding genes was found in both strain genomes. Such differential expression pattern may reflect inter-strain differences in adaptation to a specific host, in pathogenicity and or in antigenicity of this pathogenic bacterium.


Asunto(s)
Proteínas Bacterianas/química , Infecciones por Corynebacterium/veterinaria , Corynebacterium pseudotuberculosis/aislamiento & purificación , Corynebacterium pseudotuberculosis/metabolismo , Enfermedades de las Cabras/microbiología , Proteómica , Enfermedades de las Ovejas/microbiología , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Infecciones por Corynebacterium/microbiología , Corynebacterium pseudotuberculosis/química , Corynebacterium pseudotuberculosis/genética , Cabras , Ovinos
9.
Mar Drugs ; 11(3): 655-79, 2013 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-23466933

RESUMEN

Sea anemone (Cnidaria, Anthozoa) venom is an important source of bioactive compounds used as tools to study the pharmacology and structure-function of voltage-gated K+ channels (KV). These neurotoxins can be divided into four different types, according to their structure and mode of action. In this work, for the first time, two toxins were purified from the venom of Bunodosoma caissarum population from Saint Peter and Saint Paul Archipelago, Brazil. Sequence alignment and phylogenetic analysis reveals that BcsTx1 and BcsTx2 are the newest members of the sea anemone type 1 potassium channel toxins. Their functional characterization was performed by means of a wide electrophysiological screening on 12 different subtypes of KV channels (KV1.1-KV1.6; KV2.1; KV3.1; KV4.2; KV4.3; hERG and Shaker IR). BcsTx1 shows a high affinity for rKv1.2 over rKv1.6, hKv1.3, Shaker IR and rKv1.1, while Bcstx2 potently blocked rKv1.6 over hKv1.3, rKv1.1, Shaker IR and rKv1.2. Furthermore, we also report for the first time a venom composition and biological activity comparison between two geographically distant populations of sea anemones.


Asunto(s)
Venenos de Cnidarios/farmacología , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio con Entrada de Voltaje/antagonistas & inhibidores , Anémonas de Mar/química , Animales , Brasil , Venenos de Cnidarios/química , Fenómenos Electrofisiológicos , Humanos , Filogenia , Bloqueadores de los Canales de Potasio/química , Bloqueadores de los Canales de Potasio/aislamiento & purificación , Ratas , Alineación de Secuencia
10.
BMC Microbiol ; 11(1): 12, 2011 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-21241507

RESUMEN

BACKGROUND: Bacterial exported proteins represent key components of the host-pathogen interplay. Hence, we sought to implement a combined approach for characterizing the entire exoproteome of the pathogenic bacterium Corynebacterium pseudotuberculosis, the etiological agent of caseous lymphadenitis (CLA) in sheep and goats. RESULTS: An optimized protocol of three-phase partitioning (TPP) was used to obtain the C. pseudotuberculosis exoproteins, and a newly introduced method of data-independent MS acquisition (LC-MSE) was employed for protein identification and label-free quantification. Additionally, the recently developed tool SurfG+ was used for in silico prediction of sub-cellular localization of the identified proteins. In total, 93 different extracellular proteins of C. pseudotuberculosis were identified with high confidence by this strategy; 44 proteins were commonly identified in two different strains, isolated from distinct hosts, then composing a core C. pseudotuberculosis exoproteome. Analysis with the SurfG+ tool showed that more than 75% (70/93) of the identified proteins could be predicted as containing signals for active exportation. Moreover, evidence could be found for probable non-classical export of most of the remaining proteins. CONCLUSIONS: Comparative analyses of the exoproteomes of two C. pseudotuberculosis strains, in addition to comparison with other experimentally determined corynebacterial exoproteomes, were helpful to gain novel insights into the contribution of the exported proteins in the virulence of this bacterium. The results presented here compose the most comprehensive coverage of the exoproteome of a corynebacterial species so far.


Asunto(s)
Proteínas Bacterianas/análisis , Corynebacterium pseudotuberculosis/metabolismo , Proteómica/métodos , Cromatografía Liquida , Espectrometría de Masas
11.
Toxicon ; 189: 91-104, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33181162

RESUMEN

Several research groups have studied the components produced by the venom gland of the scorpion Tityus serrulatus, which has one of the most lethal venoms in the world. Various methodologies have been employed to clarify the complex mechanisms of action of these components, especially neurotoxins and enzymes. Transcriptomes and proteomes have provided important information for pharmacological, biochemical, and immunological research. Next-generation sequencing (NGS) has allowed the description of new transcripts and completion of partial sequence descriptions for peptides, especially those with low expression levels. In the present work, after NGS sequencing, we searched for new putative venom components. We present a total of nine new transcripts with neurotoxic potential (Ts33-41) and describe the sequences of one hyaluronidase (TsHyal_4); three enzymes involved in amidation (peptidyl-glycine alpha-amidating monooxygenase A, peptidyl-alpha-hydroxyglycine alpha-amidating lyase, and peptidylglycine alpha-hydroxylating monooxygenase), which increases the lethal potential of neurotoxins; and also the enzyme Ts_Chitinase1, which may be involved in the venom's digestive action. In addition, we determined the level of transcription of five groups: toxins, metalloproteases, hyaluronidases, chitinases and amidation enzymes, including new components found in this study. Toxins are the predominant group with an expression level of 91.945%, followed by metalloproteases with only 7.790% and other groups representing 0.265%.


Asunto(s)
Proteoma/química , Venenos de Escorpión/química , Escorpiones , Amidina-Liasas , Secuencia de Aminoácidos , Animales , Biología Computacional , Metaloproteasas , Oxigenasas de Función Mixta , Complejos Multienzimáticos , Transcriptoma
12.
Front Mol Biosci ; 8: 680940, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34169094

RESUMEN

Superbugs are a public health problem, increasing the need of new drugs and strategies to combat them. Our group has previously identified LyeTxI, an antimicrobial peptide isolated from Lycosa erythrognatha spider venom. From LyeTxI, we synthesized and characterized a derived peptide named LyeTxI-b, which has shown significant in vitro and in vivo activity. In this work, we elucidate the interaction of LyeTxI-b with artificial membranes as well as its effects on resistant strains of bacteria in planktonic conditions or biofilms. Isothermal titration calorimetry revealed that LyeTxI-b interacts more rapidly and with higher intensity with artificial vesicles, showing higher affinity to anionic vesicles, when compared to synthetic LyeTxI. In calcein experiments, LyeTxI-b caused greater levels of vesicle cleavage. Both peptides showed antibacterial activity at concentrations of µmol L-1 against 12 different clinically isolated strains, in planktonic conditions, in a concentration-dependent manner. Furthermore, both peptides elicited a dose-dependent production of reactive oxygen species in methicillin-resistant Staphylococcus aureus. In S. aureus biofilm assay, LyeTxI-b was more potent than LyeTxI. However, none of these peptides reduced Escherichia coli biofilms. Our results show LyeTxI-b as a promising drug against clinically resistant strains, being a template for developing new antibiotics.

13.
Toxicon ; 52(5): 611-8, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18718845

RESUMEN

MALDI-TOF-TOF and de novo sequencing were employed to assess the Tityus serrulatus venom peptide diversity. Previous works has shown the cornucopia of molecular masses, ranging from 800 to 3000Da, present in the venom from this and other scorpions species. This work reports the identification/sequencing of several of these peptides. The majority of the peptides found were fragments of larger venom toxins. For instance, 28 peptides could be identified as fragments from Pape proteins, 10 peptides corresponded to N-terminal fragments of the TsK beta (scorpine-like) toxin and fragments of potassium channel toxins (other than the k-beta) were sequenced as well. N-terminal fragments from the T. serrulatus hypotensins-I and II and a novel hypotensin-like peptide could also be found. This work also reports the sequencing of novel peptides without sequence similarities to other known molecules.


Asunto(s)
Venenos de Escorpión/química , Secuencia de Aminoácidos , Animales , Fraccionamiento Químico , Cromatografía en Gel , Datos de Secuencia Molecular , Péptidos/química , Alineación de Secuencia , Análisis de Secuencia de Proteína , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Espectrometría de Masas en Tándem
14.
J Inorg Biochem ; 102(4): 656-65, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18061680

RESUMEN

The chemical structures of the pentavalent antimonial drugs, meglumine antimonate (MA) and sodium stibogluconate (SSG), were re-evaluated using electrospray ionization mass spectrometry (ESI-MS) and osmolarity measurements. Both MA and SSG were found to contain 1:1, 1:2, 2:2 and 2:3 Sb(V)-ligand complexes. ESI-MS analysis of MA showed negatively-charged 1:1 (m/z 364) and 2:2 (m/z 765) Sb(V)-meglumine complexes, supporting the predominance of zwitterionic species in solution. Our data are consistent with a structure for the 1:2 Sb(V)-meglumine, which differs from that previously postulated, with two positively-charged amino groups and one negatively-charged antimonate group. Instead of the commonly hypothesized structure for SSG, in which two Sb atoms are linked by an oxygen, an alternative structure is proposed, based on the ability of Sb(V)-gluconate complexes to polymerize. MA (or SSG) in concentrated aqueous solutions, such as of MA (or SSG) in its commercial form, is expected to consist mainly of a mixture of 2:2, 2:3 and 2:1 Sb(V)-ligand complexes, as suggested by the 2:1 Sb-to-particle ratio found by osmometry. 1:1 Sb(V)-ligand complexes in MA and SSG are expected to play an important pharmacological role, as suggested by the slow increase of osmolarity of MA solution upon dilution at 37 degrees C (half-time of 20min).


Asunto(s)
Gluconato de Sodio Antimonio/química , Antimonio/química , Meglumina/química , Espectroscopía de Resonancia Magnética , Estructura Molecular , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masa Bombardeada por Átomos Veloces
15.
Int J Pharm ; 347(1-2): 102-8, 2008 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-17656054

RESUMEN

The composition comprising the highly water-soluble drug meglumine antimoniate (MA) and beta-cyclodextrin (beta-CD) was shown previously to enhance the absorption of Sb by oral route and render MA orally active in a murine model of cutaneous leishmaniasis. This unexpected behaviour was attributed, in part, to the fact that the heating of equimolar mixture of MA and beta-CD (first step of preparation of MA/beta-CD composition) induced the depolymerization of MA from high-molecular weight Sb complexes into 1:1 Sb-meglumine complex, resulting in an enhanced oral bioavailability of Sb. In the present work, we demonstrate that the heated MA+beta-CD mixture still produced significantly lower serum Sb levels when compared to the MA/beta-CD composition, indicating that the freeze-drying process (second step of preparation of MA/beta-CD composition) is required for achieving a high absorption of Sb by oral route. To get insight into the physicochemical alterations induced by the freeze-drying step, the MA/beta-CD composition was further characterized by circular dichroism, (1)H NMR and ESI(-)-MS and photon correlation spectroscopy. The freeze-drying process was found to promote the formation of supramolecular nanoassemblies with a mean hydrodynamic diameter of 190 nm, comprising 1:2:1, 2:2:1 and 2:2:2 NMG-Sb-beta-CD complexes. Another important observation was the ability of the MA/beta-CD composition to act as a sustained release system of the antimonial drug MA, suggesting that this property may result in the change of the drug absorption site in the gastrointestinal tract. A model is proposed for the mechanisms involved in the enhanced absorption of Sb from the MA/beta-CD composition.


Asunto(s)
Antimonio/sangre , Portadores de Fármacos/química , Meglumina/farmacocinética , Nanopartículas/química , Compuestos Organometálicos/farmacocinética , beta-Ciclodextrinas/química , Administración Oral , Animales , Antiprotozoarios/administración & dosificación , Antiprotozoarios/química , Antiprotozoarios/farmacocinética , Dicroismo Circular , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacocinética , Femenino , Liofilización , Calor , Espectroscopía de Resonancia Magnética , Meglumina/administración & dosificación , Meglumina/química , Antimoniato de Meglumina , Ratones , Modelos Biológicos , Compuestos Organometálicos/administración & dosificación , Compuestos Organometálicos/química , Tamaño de la Partícula , Espectrometría de Masa por Ionización de Electrospray
16.
Toxicon ; 49(6): 810-26, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17320133

RESUMEN

Centipedes are venomous arthropods responsible for a significant number of non-lethal human envenomations. Despite this, information about the composition and function of their venom contents is scarce. In this study, we have used a 'structure to function' proteomic approach combining two-dimensional chromatography (2D-LC), electrospray ionization quadrupole/time-of-flight mass spectrometry (ESI-Q-TOF/MS), N-terminal sequencing and similarity searching to better understand the complexities of the venoms from two Brazilian centipede species: Scolopendra viridicornis nigra and Scolopendra angulata. Comparisons between the LC profiles and the mass compositions of the venoms of the two species are provided. The observed molecular masses ranged from 3019.62 to 20996.94Da in S. viridicornis nigra (total: 62 molecular masses) and from 1304.73 to 22639.15Da in S. angulata (total: 65 molecular masses). Also, the N-termini of representatives of 10 protein/peptide families were successfully sequenced where nine of them showed no significant similarity to other protein sequences deposited in the Swiss-Prot database. A screening for insecto-toxic activities in fractions from S. viridicornis venom has also been performed. Six out of the 12 tested fractions were responsible for clear toxic effects in house flies. This work demonstrates that centipede venoms might be a neglected but important source of new bioactive compounds.


Asunto(s)
Venenos de Artrópodos/química , Artrópodos , Secuencia de Aminoácidos , Animales , Venenos de Artrópodos/toxicidad , Cromatografía Liquida , Dípteros/efectos de los fármacos , Femenino , Masculino , Datos de Secuencia Molecular , Espectrometría de Masa por Ionización de Electrospray , Relación Estructura-Actividad , Pruebas de Toxicidad
17.
J Inorg Biochem ; 101(6): 935-43, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17462741

RESUMEN

The antioxidant activity of floranol (3,5,7,2'-tetrahydroxy-6-methoxy-8-prenylflavanone), a new flavonoid isolated from the roots of Dioclea grandiflora, was evaluated by the inhibition of human low-density lipoprotein (LDL) oxidation. Floranol increased its oxidation lag-phase significantly in a dose-dependent manner. As the antioxidant mechanism may involve metal coordination, we have undertaken a detailed study of floranol interactions with Cu(II) and Fe(III) by combination of UV-visible (UV-Vis) and mass spectrometries and cyclic voltammetry. The acidity constants of the ligand as well as the stability constants of the metal complexes were calculated. The pKa values of 6.58, 11.97 and 13.87 were determined and the following acidity order is proposed 7-OH>5-OH>2'-OH. The best fit between experimental and calculated spectra was obtained assuming the formation of two Cu(II) complexes: [CuL] logbeta=19.34+/-0.05 and [CuL(2)](2-) logbeta=26.4+/-0.10 and three Fe(III) complexes: [FeL(3)](3-) logbeta=44.72+/-0.09, [FeL(2)](-) logbeta=35.32+/-0.08 and [FeL](+) logbeta=19.51+/-0.04. In addition, copper and iron reduction is less favorable in the presence of floranol. These results indicate that floranol can efficiently bind Cu(II) and Fe(III) ions thus preventing their effect on LDL oxidation.


Asunto(s)
Cobre/química , Flavonoides/química , Lipoproteínas LDL/química , Zinc/química , Humanos , Oxidación-Reducción , Espectrometría de Masa por Ionización de Electrospray
18.
Carbohydr Res ; 342(15): 2286-96, 2007 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-17618611

RESUMEN

The supramolecular assembly between chlorhexidine and cyclomaltoheptaose (beta-cyclodextrin, betaCD) was characterized using NMR spectroscopy ((1)H, T(1), and ROESY), ESIMS and ITC. NMR data suggest the formation of high ordered complexes. ESIMS and ITC allowed the confirmation of the average stoichiometry as 1:4 and the thermodynamic data, also obtained by ITC, showed that the assembly is strongly stabilized by short distance interactions, but suffers a strong, opposite effect of entropy reduction. The antimicrobial activity of 1:1, 1:2, 1:3, and 1:4 Clx/betaCD molar ratio mixtures was investigated in aqueous solution and after incorporation into mucoadhesive gels. These were used to determine the initial and the long-term antimicrobial activity, respectively, toward Actinobacillus actinomycetemcomitans (A.a.) (Y4-FDC) and Enterococcus faecalis (E.f.) (ATCC 14508) strains. The results showed that A.a. and E.f. were more susceptible to the 1:4 molar ratio mixture in either solution or gel (p<0.05).


Asunto(s)
Antiinfecciosos Locales/química , Clorhexidina/química , Portadores de Fármacos , beta-Ciclodextrinas/química , Actinobacillus/metabolismo , Antiinfecciosos Locales/administración & dosificación , Calorimetría/métodos , Clorhexidina/administración & dosificación , Evaluación Preclínica de Medicamentos , Enterococcus faecalis/metabolismo , Geles/química , Cinética , Espectroscopía de Resonancia Magnética/métodos , Espectrometría de Masas/métodos , Modelos Químicos , Conformación Molecular , Espectrometría de Masa por Ionización de Electrospray/métodos
19.
Artículo en Inglés | MEDLINE | ID: mdl-28791255

RESUMEN

Corynebacterium pseudotuberculosis biovar equi is the etiologic agent of ulcerative lymphangitis. To investigate proteins that could be related to the virulence of this pathogen, we combined an experimental passage process using a murine model and high-throughput proteomics with a mass spectrometry, data-independent acquisition (LC-MSE) approach to identify and quantify the proteins released into the supernatants of strain 258_equi. To our knowledge, this approach allowed characterization of the exoproteome of a C. pseudotuberculosis equi strain for the first time. Interestingly, the recovery of this strain from infected mouse spleens induced a change in its virulence potential, and it became more virulent in a second infection challenge. Proteomic screening performed from culture supernatant of the control and recovered conditions revealed 104 proteins that were differentially expressed between the two conditions. In this context, proteomic analysis of the recovered condition detected the induction of proteins involved in bacterial pathogenesis, mainly related to iron uptake. In addition, KEGG enrichment analysis showed that ABC transporters, bacterial secretion systems and protein export pathways were significantly altered in the recovered condition. These findings show that secretion and secreted proteins are key elements in the virulence and adaptation of C. pseudotuberculosis. Collectively, bacterial pathogenesis-related proteins were identified that contribute to the processes of adherence, intracellular growth and evasion of the immune system. Moreover, this study enhances our understanding of the factors that may influence the pathogenesis of C. pseudotuberculosis.


Asunto(s)
Proteínas Bacterianas/metabolismo , Infecciones por Corynebacterium/microbiología , Corynebacterium pseudotuberculosis/aislamiento & purificación , Medios de Cultivo/química , Proteoma/análisis , Animales , Cromatografía Liquida , Corynebacterium pseudotuberculosis/crecimiento & desarrollo , Modelos Animales de Enfermedad , Ensayos Analíticos de Alto Rendimiento , Espectrometría de Masas , Ratones , Proteómica
20.
Peptides ; 98: 63-69, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27732900

RESUMEN

We have previously described a 25mer anti-hypertensive peptide, previously named TsHpt-I (Tityus serrulatus Hypotensin-I), now Ts14, as an agonist of B2 kinin receptor. Bradykinin is known to play physiological roles in angiogenic, inflammatory, and fibrogenic processes, mostly mediated by B2 receptor. Therefore, we investigated whether Ts14 could modulate key events (neovascularization, inflammatory cell recruitment, and extracellular matrix deposition) of the fibrovascular tissue, induced by polyether-polyurethane sponge implants in mice. Sponges were implanted in the dorsum of 7-week-old C57Bl/6 male mice that received daily intrasponge treatment with Ts14 (27.25µg/sponge/day in 10µL PBS) or vehicle (10µL PBS/sponge/day) and were assessed on day 7 after surgery. Hemoglobin content, blood flow (laser Doppler perfusion imaging), and VEGF levels in the implants, used as indices of vascularization, indicated that Ts14 enhanced angiogenesis in implants relative to the PBS-treated group. Interestingly, Ts14 reduced TNF-α levels and neutrophil infiltration, although stimulated macrophage infiltration into implants, as determined by myeloperoxidase (MPO) and N-acetyl-ß-d-glucosaminidase (NAG) enzyme activities, respectively. Regarding the fibrogenic component (soluble collagen content and Sirius-red histological staining), we observed that Ts14 inhibited collagen deposition in the implants. Overall, our results suggest that Ts14 exerts proangiogenic, anti-inflammatory, and anti-fibrogenic activities. These effects may indicate a therapeutical potential of this peptide in conditions where angiogenesis, inflammation, and fibrogenesis contribute to disease progression and chronicity.


Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Antiinflamatorios no Esteroideos/farmacología , Antihipertensivos/farmacología , Colágeno/metabolismo , Tejido de Granulación/efectos de los fármacos , Neovascularización Fisiológica/efectos de los fármacos , Venenos de Escorpión/farmacología , Inhibidores de la Angiogénesis/química , Animales , Antiinflamatorios no Esteroideos/química , Antihipertensivos/química , Biomarcadores/análisis , Modelos Animales de Enfermedad , Éteres , Tejido de Granulación/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Poliuretanos , Venenos de Escorpión/química
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