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1.
J Obstet Gynaecol Res ; 46(11): 2221-2236, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32830415

RESUMO

OBJECTIVE: This review aims to analyze the pathological aspects, diagnosis and treatment of rare mesenchymal uterine tumors. METHODS: On August 2019, a systematic review of the literature was done on Pubmed, MEDLINE, Scopus, and Google Scholar search engines. The systematic review was carried out in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes statement (PRISMA). The following words and key phrases have been searched: "endometrial stromal sarcoma", "low-grade endometrial stromal sarcoma", "high-grade endometrial stromal sarcoma", "uterine sarcoma", "mesenchymal uterine tumors" and "uterine stromal sarcoma". Across these platforms and research studies, five main aspects were analyzed: the biological characteristics of the neoplasms, the number of cases, the different therapeutic approaches used, the follow-up and the oncological outcomes. RESULTS: Of the 94 studies initially identified, 55 were chosen selecting articles focusing on endometrial stromal sarcoma. Of these fifty-five studies, 46 were retrospective in design, 7 were reviews and 2 randomized phases III trials. CONCLUSION: Endometrial stromal sarcomas are rare mesenchymal uterine neoplasms and surgery represents the standard treatment. For uterus-limited disease, the remove en bloc with an intact resection of the tumor (without the use of morcellation) is strongly recommended. For advanced-stage disease, the standard surgical treatment is adequate cytoreduction with metastatectomy. Pelvic and para-aortic lymphadenectomy is not recommended in patients with Low-grade Endometrial Stromal Sarcoma (ESS), while is not clear whether cytoreduction of advanced tumors improves patient survival in High-grade ESS. Administration of adjuvant radiotherapy or chemotherapy is not routinely used and its role is still debated.


Assuntos
Neoplasias do Endométrio , Sarcoma do Estroma Endometrial , Neoplasias Uterinas , Neoplasias do Endométrio/diagnóstico , Neoplasias do Endométrio/cirurgia , Feminino , Humanos , Estudos Retrospectivos , Sarcoma do Estroma Endometrial/diagnóstico , Sarcoma do Estroma Endometrial/cirurgia , Neoplasias Uterinas/cirurgia
2.
Ann Clin Lab Sci ; 44(3): 286-90, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25117099

RESUMO

INTRODUCTION: Hypertension is considered to be among the most important risk factors for cardiovascular and cerebrovascular diseases. In recent years, several investigators have reported that high plasma levels of total homocysteine (t-hcy) has a key role in the development of hypertension, and the deficiency of B complex vitamins could increase the risk of hypertension. The purpose of this study was to investigate the relationship between plasma homocysteine, folate and vitamin B12 in hypertensive patients. MATERIALS AND METHODS: In 116 patients with hypertension and 81 healthy subjects, total plasma homocysteine, vitamin B12 and folate levels were measured. RESULTS AND DISCUSSION: Homocysteine was significantly higher in patients than in control subjects (22.9±3.5 versus 9.0±2.3 µmol/L respectively, p<0.001); the folate plasma concentrations in hypertensive patients were significantly lower than in control subjects (6.7±5.0 ng/ml and 9.0±4.4 ng/ml respectively, p<0.05). Moreover, no differences in vitamin B12 plasma levels were observed when comparing the levels of hypertensive patients and those of the controls (440±223 pg/ml vs 491±185 pg/ml respectively, p>0.05). Our results confirmed that, as previously observed, elevated t-hcy levels and low folate levels, but not vitamin B12 levels, are significantly associated with hypertension.


Assuntos
Ácido Fólico/sangue , Hiper-Homocisteinemia/sangue , Hipertensão/sangue , Vitamina B 12/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Padrões de Referência
3.
Mol. Biotechnol ; 51(2): p.119-27, 2012.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: but-ib8001
6.
Eur J Neurol ; 17(1): 84-9, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19659753

RESUMO

BACKGROUND: High cerebrospinal fluid (CSF) and plasma levels of homocysteine (HC) have been reported in certain neurodegenerative disorders, such as Alzheimer's, Parkinson's diseases and, recently, amyotrophic lateral sclerosis (ALS). OBJECTIVES: To assay the CSF and plasma levels of HC in ALS patients and controls, and to evaluate the relationship between HC levels and clinical variables of the disease. METHODS: Cerebrospinal fluid from sixty-nine (M/F 1.87) and plasma from sixty-five ALS patients (M/F 1.83) were taken and stored at -80 degrees C until use. Controls (CSF = 55; plasma = 67) were patients admitted to our hospital for neurological disorders with no known relationship to HC changes. CSF and plasma from ALS patients and controls were obtained as a necessary step of the diagnostic workup. HC levels in CSF and plasma were assayed using a high performance liquid chromatograph (HPLC) and a fluorimeter detector. RESULTS: The median level of total HC in the CSF of ALS patients was 0.46( )microM, significantly higher than that of the controls (0.24 microM, +91.6%, P < 0.001). A similar trend was observed when HC was assayed in plasma (ALS, 12.4 microM vs. controls, 7.26 microM, +70.8%, P < 0.001). The CSF and plasma HC levels showed no relationship with the disease progression, age at onset, and the site of onset. CONCLUSIONS: Homocysteine is a biochemical marker in ALS, and it might be related to the pathophysiology of the disease.


Assuntos
Esclerose Lateral Amiotrófica/sangue , Esclerose Lateral Amiotrófica/líquido cefalorraquidiano , Homocisteína/sangue , Homocisteína/líquido cefalorraquidiano , Hiper-Homocisteinemia/sangue , Hiper-Homocisteinemia/líquido cefalorraquidiano , Idoso , Esclerose Lateral Amiotrófica/fisiopatologia , Biomarcadores/análise , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/fisiopatologia , Comorbidade , Feminino , Homocisteína/análise , Humanos , Hiper-Homocisteinemia/diagnóstico , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes
8.
J Dent ; 36(4): 268-71, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18313197

RESUMO

OBJECTIVES: The protective role of saliva in the case of oesophageal exposition to gastric acid has long been studied but some contradictions still remain. The main end-point of this study was to evaluate if a qualitative and quantitative alteration in salivary secretion exists in patients affected by GERD. METHODS: One hundred and twenty patients (T group) with clinically and endoscopically diagnosed GERD, and 98 healthy subjects (C group) have been evaluated; salivary tests (i.e. basal flow rate, stimulated flow rate, pH, [Na(+)] and [K(+)]) were performed, socio-demographical variables and oral GERD-related symptoms were taken into account. SPSS 10.5 software was used for statistical univariate and multivariate analyses. RESULTS: GERD patients and controls were found to have a similar basal flow rate but different stimulated salivary function [T group mean value 0.989 ml/min (+/-0.48718) vs. C group 1.2197 ml/min (+/-0.6108), pH [T group mean value 8.935 (+/-0.471) vs. C group 7.879 (+/-0.526)] and a higher K(+) concentration. In GERD patients we also registered a significant association with xerostomia [69/120 (57.5%) vs. 28/98 (28.7%)] and an oral burning sensation [58/120 (48.3%) vs. 19/98 (19.3%)]. CONCLUSIONS: Our findings assess that salivary secretion is altered in GERD patients and highlight the need for further investigations in order to define the role of saliva in the etiopathogenesis of GERD.


Assuntos
Refluxo Gastroesofágico/fisiopatologia , Saliva , Adulto , Idoso , Síndrome da Ardência Bucal/complicações , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Estudos Transversais , Feminino , Refluxo Gastroesofágico/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Saliva/química , Saliva/metabolismo , Saliva/fisiologia , Taxa Secretória , Estatísticas não Paramétricas , Xerostomia/complicações
9.
Biochimie ; 90(3): 484-92, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18096518

RESUMO

Snake venom metalloproteinases (SVMPs) are multifunctional enzymes involved in several symptoms following snakebite, such as severe local hemorrhage. Multidomain P-III SVMPs are strongly hemorrhagic, whereas single domain P-I SVMPs are not. This indicates that disintegrin-like and cysteine-rich domains allocate motifs that enable catalytic degradation of ECM components leading to disruption of capillary vessels. Interestingly, some P-III SVMPs are completely devoid of hemorrhagic activity despite their highly conserved disintegrin-like and cysteine-rich domains. This observation was approached in the present study by comparing the effects of jararhagin, a hemorrhagic P-III SVMP, and berythractivase, a pro-coagulant and non-hemorrhagic P-III SVMP. Both toxins inhibited collagen-induced platelet aggregation, but only jararhagin was able to bind to collagen I with high affinity. The monoclonal antibody MAJar 3, that neutralizes the hemorrhagic effect of Bothrops venoms and jararhagin binding to collagen, did not react with berythractivase. The three-dimensional structures of jararhagin and berythractivase were compared to explain the differential binding to collagen and MAJar 3. Thereby, we pinpointed a motif within the Da disintegrin subdomain located opposite to the catalytic domain. Jararhagin binds to both collagen I and IV in a triple helix-dependent manner and inhibited in vitro fibrillogenesis. The jararhagin-collagen complex retained the catalytic activity of the toxin as observed by hydrolysis of fibrin. Thus, we suggest that binding of hemorrhagic SVMPs to collagens I and IV occurs through a motif located in the Da subdomain. This allows accumulation of toxin molecules at the site of injection, close to capillary vessels, where their catalytic activity leads to a local hemorrhage. Toxins devoid of this motif would be more available for vascular internalization leading to systemic pro-coagulant effects. This reveals a novel function of the disintegrin domain in hemorrhage formation.


Assuntos
Colágeno/efeitos dos fármacos , Venenos de Crotalídeos/toxicidade , Metaloendopeptidases/toxicidade , Sequência de Aminoácidos , Animais , Sítios de Ligação , Colágeno/química , Colágeno/metabolismo , Venenos de Crotalídeos/química , Venenos de Crotalídeos/metabolismo , Metaloendopeptidases/química , Metaloendopeptidases/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Inibidores da Agregação Plaquetária/química , Inibidores da Agregação Plaquetária/metabolismo , Veneno de Bothrops jararaca
11.
Haematologica ; 93(5): p.797-8, 2008.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: but-ib7283
12.
Curr Pharm Des ; 13(28): 2893-905, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17979734

RESUMO

Snake venom metalloproteinases (SVMPs) are widely distributed in snake venoms and play important roles in hemostatic disorders and local tissue damage that follows snakebite. The impact of SVMPs on hemostasis has been extensively studied showing diverse effects both on soluble factors and cellular components. The action of SVMPs involves catalytic and anti-adhesive properties, as well as direct cellular activation and/or the release of endogenous bioactive components. The purpose of this review is to overview the action of SVMPs on the inhibition of platelet functions; angiogenesis, particularly inducing apoptosis of endothelial cells; and regarding the pro-inflammatory reaction that follows snakebite. We discuss the structural features of the molecules that may be involved in such activities. The versatility and availability of SVMPs make them important tools for cell biology research into the mechanisms of action of endogenous metalloproteinases, for insights into cellular-matrix interactions and for clinical investigations into the treatment of snakebites.


Assuntos
Plaquetas/enzimologia , Células Endoteliais/enzimologia , Mediadores da Inflamação/fisiologia , Metaloproteases/fisiologia , Venenos de Serpentes/enzimologia , Animais , Plaquetas/patologia , Células Endoteliais/patologia , Humanos , Mediadores da Inflamação/química , Metaloproteases/química , Venenos de Serpentes/química
13.
J Agric Food Chem ; 55(21): 8465-71, 2007 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-17887802

RESUMO

An increasing body of evidence on the association between adherence to the Mediterranean diet and healthy status is being accumulated. Floral buds of Capparis spinosa L. are commonly used in the Mediterranean cuisine as flavoring for meat and other foods. The present study evaluated bioactive components and antioxidant activity of Sicilian capers stabilized in salt. Whereas alpha-tocopherol was absent, low levels of gamma-tocopherol and vitamin C were measured. With reference to one serving size (8.6 g of capers), rutin was 13.76 mg, isothiocyanates, recently acknowledged as anticarcinogen phytochemicals, were 42.14 micromol, total phenols were 4.19 mg of gallic acid equivalents (GAE), and the total antioxidant potential measured using the [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] diammonium salt (ABTS) cation radical decolorization assay was 25.8 micromol of Trolox equivalents. The antioxidative activity of a caper hydrophilic extract was assessed in a number of assays. The extract at 3.5 and 7.0 microM GAE exhibited a dose-dependent peroxyl radical scavenging activity in a methyl linoleate methanol solution oxidized by azo initiator, and reduced hypervalent iron myoglobin species formed from met-Mb an H 2O 2, at 180 microM GAE. The hydrophilic extract, at 70-280 microM GAE, caused a dose-dependent inhibition of lipid autoxidation in heated red meat, incubated with simulated gastric fluid for 180 min. In the same model rutin tested at a concentration corresponding to its content in the extract was ineffective, and alpha-tocopherol at 25 microM was poorly effective. The hydrophilic extract (70 microM GAE) prevented the consumption of the co-incubated alpha-tocopherol, whereas lipid oxidation was inhibited for the experimental time, suggesting cooperative interactions between extract components and the vitamin. The findings encourage the use of caper with foods that contribute oxidizable lipids in view of the association between dietary oxidized lipids and risk of oxidative stress-based diseases.


Assuntos
Antioxidantes/farmacologia , Capparis/química , Digestão , Carne/análise , Extratos Vegetais/farmacologia , Animais , Suco Gástrico , Temperatura Alta , Peroxidação de Lipídeos/efeitos dos fármacos , Modelos Biológicos , Estresse Oxidativo/efeitos dos fármacos , Sicília , Substâncias Reativas com Ácido Tiobarbitúrico/análise
14.
Free Radic Res ; 41(2): 226-33, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17364949

RESUMO

The reaction of the phytochemical indicaxanthin with lipoperoxyl radicals generated in methyl linoleate methanol solution by 2,2'-azobis(2,4-dimethylvaleronitrile), and in aqueous soybean phosphatidylcholine unilamellar liposomes by 2,2'-azobis(2-amidinopropane)hydrochloride, was studied. The molecule acts as a chain-terminating lipoperoxyl radical scavenger in solution, with a calculated inhibition constant of 3.63 x 10(5) M(-1) s(-1), and a stoichiometric factor approaching 2. Indicaxanthin incorporated in liposomes prevented lipid oxidation, inducing clear-cut lag periods and decrease of the propagation rate. Both effects were concentration-dependent, but not linearly related to the phytochemical concentration. The consumption of indicaxanthin during liposome oxidation was remarkably delayed, the lower the concentration the longer the time-interval during which it remained in its native state. Indicaxanthin and alpha-tocopherol, simultaneously incorporated in liposomes, exhibited cooperative antioxidant effects and reciprocal protective interactions. The extent of synergism decreased at the increase of the ratio (indicaxanthin)/(alpha-tocopherol). A potential antioxidant mechanism of indicaxanthin is discussed in the context of the chemistry of the molecule, and of the possible reactivity of a short-lived intermediate.


Assuntos
Antioxidantes/metabolismo , Betaxantinas/metabolismo , Sequestradores de Radicais Livres/metabolismo , Peróxidos Lipídicos/metabolismo , Lipossomos/metabolismo , Piridinas/metabolismo , 1,2-Dipalmitoilfosfatidilcolina/metabolismo , Amidinas/farmacologia , Antioxidantes/farmacologia , Compostos Azo/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Técnicas In Vitro , Cinética , Ácidos Linoleicos/metabolismo , Bicamadas Lipídicas , Peroxidação de Lipídeos , Metanol , Estrutura Molecular , Nitrilas/farmacologia , Oxirredução , Fosfatidilcolinas/metabolismo , Soluções , Solventes , Suspensões , alfa-Tocoferol/metabolismo , alfa-Tocoferol/farmacologia
16.
Free Radic Res ; 40(7): 753-61, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16984002

RESUMO

Antioxidant phytochemicals are investigated as novel treatments for supportive therapy in beta-thalassemia. The dietary indicaxanthin was assessed for its protective effects on human beta-thalassemic RBCs submitted in vitro to oxidative haemolysis by cumene hydroperoxide. Indicaxanthin at 1.0-10 microM enhanced the resistance to haemolysis dose-dependently. In addition, it prevented lipid and haemoglobin (Hb) oxidation, and retarded vitamin E and GSH depletion. After ex vivo spiking of blood from thalassemia patients with indicaxanthin, the phytochemical was recovered in the soluble cell compartment of the RBCs. A spectrophotometric study showed that indicaxanthin can reduce perferryl-Hb generated in solution from met-Hb and hydrogen peroxide (H2O2), more effectively than either Trolox or vitamin C. Collectively our results demonstrate that indicaxanthin can be incorporated into the redox machinery of beta-thalassemic RBC and defend the cell from oxidation, possibly interfering with perferryl-Hb, a reactive intermediate in the hydroperoxide-dependent Hb degradation. Opportunities of therapeutic interest for beta-thalassemia may be considered.


Assuntos
Antioxidantes/farmacologia , Betaxantinas/farmacologia , Citoproteção , Eritrócitos/efeitos dos fármacos , Piridinas/farmacologia , Talassemia beta/sangue , Antioxidantes/metabolismo , Derivados de Benzeno/toxicidade , Betaxantinas/metabolismo , Estudos de Casos e Controles , Relação Dose-Resposta a Droga , Eritrócitos/metabolismo , Glutationa/sangue , Hemina/metabolismo , Hemoglobinas/metabolismo , Hemólise , Humanos , Metabolismo dos Lipídeos , Oxirredução , Piridinas/metabolismo , Espectrofotometria , Vitamina E/sangue
17.
Toxicon ; 46(2): p.178-84, 2005.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: but-ib8583
18.
J Virol ; 78(16): 8496-505, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15280458

RESUMO

We recently reported that retroviral pseudotypes bearing the hepatitis C virus (HCV) strain H and Con1 glycoproteins, genotype 1a and 1b, respectively, require CD81 as a coreceptor for virus-cell entry and infection. Soluble truncated E2 cloned from a number of diverse HCV genotypes fail to interact with CD81, suggesting that viruses of diverse origin may utilize different receptors and display altered cell tropism. We have used the pseudotyping system to study the tropism of viruses bearing diverse HCV glycoproteins. Viruses bearing these glycoproteins showed a 150-fold range in infectivity for hepatoma cells and failed to infect lymphoid cells. The level of glycoprotein incorporation into particles varied considerably between strains, generally reflecting the E2 expression level within transfected cells. However, differences in glycoprotein incorporation were not associated with virus infectivity, suggesting that infectivity is not limited by the absolute level of glycoprotein. All HCV pseudotypes failed to infect HepG2 cells and yet infected the same cells after transduction to express human CD81, confirming the critical role of CD81 in HCV infection. Interestingly, these HCV pseudotypes differed in their ability to infect HepG2 cells expressing a panel of CD81 variants, suggesting subtle differences in the interaction of CD81 residues with diverse viral glycoproteins. Our current model of HCV infection suggests that CD81, together with additional unknown liver specific receptor(s), mediate the virus-cell entry process.


Assuntos
Antígenos CD/metabolismo , Hepacivirus/classificação , Hepacivirus/patogenicidade , Hepatócitos/virologia , Proteínas do Envelope Viral/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular , Linhagem Celular Tumoral , Células Cultivadas , HIV-1/genética , HIV-1/metabolismo , Hepacivirus/genética , Hepacivirus/fisiologia , Humanos , Fígado , Linfócitos/virologia , Camundongos , Dados de Sequência Molecular , Especificidade de Órgãos , Tetraspanina 28 , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética
19.
Free Radic Res ; 37(6): 689-96, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12868496

RESUMO

Betalains are natural pigments recently considered as compounds with potential antioxidative properties. In this work, ex vivo plasma spiking of pure either betanin or indicaxanthin, followed by isolation of low density lipoprotein (LDL), and measurement of its resistance to copper-induced oxidation, has been used to research if these betalains can bind to LDL and prevent oxidation of LDL lipids. When pooled human plasma from 10 healthy volunteers was incubated in the presence of 25-100 microM either betanin or indicaxanthin, incorporation of both compounds in LDL was observed, with a maximum binding of 0.52 +/- 0.08, and 0.51 +/- 0.06 nmoles of indicaxanthin and betanin, respectively, per mg LDL protein. Indicaxanthin-enriched and betanin-enriched LDL were more resistant than homologous native LDL to copper-induced oxidation, as assessed by the elongation of the induction period. The incorporated indicaxanthin, however, appeared twice as effective as betanin in increasing the length of the lag phase, while both compounds did not affect the propagation rate. Both betalains were consumed during the inhibition period of lipid oxidation, and delayed consumption of LDL-beta carotene. Indicaxanthin, but not betanin, prevented vitamin E consumption at the beginning of LDL oxidation, and prolonged the time of its utilization. The resistance of LDL to oxidation when vitamin E and indicaxanthin acted separately in a sequence, was lower than that measured when they were allowed to act in combination, indicating some synergistic interaction between the two molecules. No prooxidant effect over a large concentration range of either betanin or indicaxanthin was observed, when either betalain was added to the LDL system undergoing a copper-induced oxidation. These results show than indicaxanthin and betanin may bind to LDL, and are highly effective in preventing copper-induced lipid oxidation. Interaction with vitamin E appears to add a remarkable potential to indicaxanthin in the protection of LDL. Although molecular mechanisms remain uncompletely understood, various aspects of the action of betanin and indicaxanthin in preventing LDL lipid oxidation are discussed.


Assuntos
Lipoproteínas LDL/química , Oxigênio/metabolismo , Compostos de Amônio Quaternário/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Betalaínas , Relação Dose-Resposta a Droga , Humanos , Peróxido de Hidrogênio/química , Modelos Químicos , Ligação Proteica , Pyrus , Fatores de Tempo
20.
Arch Biochem Biophys ; 409(2): 395-401, 2003 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-12504907

RESUMO

The reprolysin subfamily of metalloproteinases includes snake venom metalloproteinases (SVMP) and mammalian disintegrin/metalloproteinase. These proteins are synthesized as zymogens and undergo proteolytic processing resulting in a variety of multifunctional proteins. Jararhagin is a P-III SVMP isolated from the venom of Bothrops jararaca. In crude venom, two forms of jararhagin are typically found, full-length jararhagin and jararhagin-C, a proteolytically processed form of jararhagin that is composed of the disintegrin-like and cysteine-rich domains of jararhagin. To better understand the structural and mechanistic bases for these forms of jararhagin in the venom of B. jararaca and the source of venom complexity in general, we have examined the jararhagin forms isolated from venom and the autolysis of isolated jararhagin under the conditions of varying pH, calcium ion concentration, and reducing agents. From our results, jararhagin isolated from venom appears as two forms: a predominant form that is stable to in vitro autolysis and a minor form that is susceptible to autolysis under a variety of conditions including alkaline pH, low calcium ion concentrations, or reducing agent. The autolysis site for production of jararhagin-C from isolated jararhagin was different from that observed for jararhagin-C as isolated from crude venom. Taken together, these data lead us to the conclusion that during the biosynthesis of jararhagin in the venom gland at least three forms are present: one form which is rapidly processed to give rise to jararhagin-C, one form which is resistant to processing in the venom and autolysis in vitro, and one minor form which is susceptible to autolysis under conditions that promote destabilization of its structure. The presence of these different forms of jararhagin contributes to greater structural and functional complexity of the venom and may be a common feature among all snake venoms. The biological and biochemical features in the venom gland responsible for these jararhagin isoforms are currently under investigation.


Assuntos
Bothrops , Venenos de Crotalídeos/genética , Variação Genética , Metaloendopeptidases/genética , Sequência de Aminoácidos , Animais , Cálcio/farmacologia , Cromatografia Líquida , Venenos de Crotalídeos/química , Venenos de Crotalídeos/isolamento & purificação , Cisteína/química , Desintegrinas/química , Concentração de Íons de Hidrogênio , Espectrometria de Massas , Metaloendopeptidases/química , Metaloendopeptidases/efeitos dos fármacos , Metaloendopeptidases/isolamento & purificação , Peso Molecular , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Veneno de Bothrops jararaca
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