A comparison of the enzymatic properties of the major cysteine proteinases from Trypanosoma congolense and Trypanosoma cruzi

A comparison of the enzymatic properties of the major cysteine proteinases from Trypanosoma congolense and Trypanosoma cruzi

Autor Chagas, JR Google Scholar
Authie, E. Google Scholar
Serveau, C. Google Scholar
Lalmanach, G. Google Scholar
Juliano, L. Google Scholar
Gauthier, F. Google Scholar
Instituição UNIV TOURS
ILRI
Universidade Federal de São Paulo (UNIFESP)
Resumo Congopain and cruzipain, the major cysteine proteinases from Trypanosoma congolense and Trypanosoma cruzi, were compared for their activities towards a series of new, sensitive fluorogenic substrates of the papain family of cysteine proteinases and far their sensitivity to inhibition by cystatins and related biotinylated peptidyl diazomethanes. Low K-i values, in the 10 pM range, were found for the interaction of both proteinases with natural cystatin inhibitors. the kinetic constants for the hydrolysis of cystatin-derived substrates, and the inhibition by related diazomethanes were essentially identical. Unlike cathepsins B and L, the related mammal papain family proteinases, congopain and cruzipain accomodate a prolyl residue in P2'. Substrates having the sequence VGGP from P2 to P2' were hydrolysed by both congopain and cruzipain with a k(cat)/K-m greater than 4.10(3) mM(-1) s(-1). Irreversible diazomethane inhibitors, deduced from the unprime sequence of cystatin-derived substrates, inhibited the two parasite proteinases. N-terminal labelling of diazomethanes with a biotin group did not alter the rate of inhibition significantly, which provides a useful tool for examining the distribution of these enzymes in the parasite and in the host. Despite their similar activities on cystatin-derived substrates, congopain and cruzipain had significantly different pH-activity profiles when assayed with a cystatin-derived substrate. They were correlated with structural differences, especially at the presumed S2 subsites. (C) 1997 Elsevier Science B.V.
Palavra-chave Trypanosoma congolense
Trypanosoma cruzi
cysteine proteinase
cystatin
Idioma Inglês
Data de publicação 1997-09-01
Publicado em Molecular and Biochemical Parasitology. Amsterdam: Elsevier B.V., v. 88, n. 1-2, p. 85-94, 1997.
ISSN 0166-6851 (Sherpa/Romeo, fator de impacto)
Publicador Elsevier B.V.
Extensão 85-94
Fonte http://dx.doi.org/10.1016/S0166-6851(97)00085-6
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:A1997XR36500009
Endereço permanente http://repositorio.unifesp.br/handle/11600/25785

Exibir registro completo




Arquivo

Arquivo Tamanho Formato Visualização

Não existem arquivos associados a este item.

Este item está nas seguintes coleções

Buscar


Navegar

Minha conta