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2030-01-01
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- IOC - Artigos de Periódicos [12642]
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TRYPANOSOMA CRUZI: ISOLATION AND CHARACTERIZATION OF ASPARTYL PROTEASES
Affilliation
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunologia Clínica. Rio de Janeiro, RJ, Brasil.
Universidade de São Paulo. Instituto de Física de São Carlos. Departamento de Física e Informática. São paulo, SP, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz., Laboratório de Bioquímica de Proteínas e Peptídeos. Rio de Janeiro, RJ, Brasil / Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Celular e Molecular. Niterói, RJ, Brasil.
Universidade de São Paulo. Instituto de Física de São Carlos. Departamento de Física e Informática. São paulo, SP, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz., Laboratório de Bioquímica de Proteínas e Peptídeos. Rio de Janeiro, RJ, Brasil / Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Celular e Molecular. Niterói, RJ, Brasil.
Abstract
Two aspartyl proteases activities were identified and isolated from Trypanosoma cruzi epimastigotes: cruzipsin-I (CZP-I) and cruzipsin-II (CZP-II). One was isolated from a soluble fraction (CZP-II) and the other was solubilized with 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CZP-I). The molecular mass of both proteases was estimated to be 120 kDa by HPLC gel filtration and the activity of the enzymes was detected in a doublet of bands (56 and 48 kDa) by substrate-sodium dodecyl sulphate-polyacrylamide-gelatin gel electrophoresis. Substrate specificity studies indicated that the enzymes consistently hydrolyze the cathepsin D substrate Phe-Ala-Ala-Phe (4-NO2)-Phe-Val-Leu-O4MP but failed to hydrolyze serine and other protease substrates. Both proteases activities were strongly inhibited by the classic inhibitor pepstatin-A (> or =68%) and the aspartic active site labeling agent, 1,2-epoxy-3-(phenyl-nitrophenoxy) propane (> or =80%). These findings show that both proteases are novel T. cruzi acidic proteases. The physiological function of these enzymes in T. cruzi has under investigation.
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