NEW SUBSTRATES of PAPAIN, BASED ON the CONSERVED SEQUENCE of NATURAL INHIBITORS of the CYSTATIN FAMILY

NEW SUBSTRATES of PAPAIN, BASED ON the CONSERVED SEQUENCE of NATURAL INHIBITORS of the CYSTATIN FAMILY

Autor Serveau, C. Google Scholar
Juliano, L. Google Scholar
Bernard, P. Google Scholar
Moreau, T. Google Scholar
Mayer, R. Google Scholar
Gauthier, F. Google Scholar
Instituição UNIV TOURS
Universidade Federal de São Paulo (UNIFESP)
CTR BIOPHYS MOLEC
Resumo A series of peptide substrates with different fluorogenic leaving groups has been synthesized. the peptide moiety in these substrates mimics a highly conserved sequence (QVVAG) in the natural reversible inhibitors of cysteine proteinases, the cystatins, that participates to the tight binding of target proteinases. This sequence is invariably cleaved at the A-G bond when synthetic peptides containing it were incubated with papain. AEC and AMC fluorophores were therefore attached to the Ala residue to construct new substrates for cysteine proteinases. the solubility of the resulting substrates was improved by attaching a N-terminal gluconoyl group, or by introducing an arginyl residue at P5 (nomenclature of Schechter I, Berger A (1967) Biochem Biophys Res Commun 27, 157-162). Neither induced significant changes in the k(cat)/K-m values with papain. Those values were all in the 10(5) M(-1) s(-1) range. the k(cat)/K-m was increased 10-50-fold by using substrates with intramolecularly quenched fluorescence. With these, the enzyme specificity on both sides of the scissile bond can be investigated. the substrate Abz-QVVAGA-EDDnp is among the most sensitive papain substrates ever reported, with a k(cat)/K-m, value of 29 10(6) M(-1) s(-1). the positioning and conformation of the bound QVVA moiety within the active site of papain were predicted by molecular modelling using the X-ray coordinates of a peptide inhibitor-papain complex.
Palavra-chave CYSTEINE PROTEINASE
PAPAIN
CYSTATIN
FLUOROGENIC SUBSTRATE
Idioma Inglês
Data de publicação 1994-01-01
Publicado em Biochimie. Paris: Elsevier France-editions Scientifiques Medicales Elsevier, v. 76, n. 2, p. 153-158, 1994.
ISSN 0300-9084 (Sherpa/Romeo, fator de impacto)
Publicador Elsevier B.V.
Extensão 153-158
Fonte http://dx.doi.org/10.1016/0300-9084(94)90007-8
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:A1994NL37600007
Endereço permanente http://repositorio.unifesp.br/handle/11600/25375

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