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Specificity of cathepsin B to fluorescent substrates containing benzyl side-chain-substituted amino acids at P1 subsite.
Del Nery, E; Alves, L C; Melo, R L; Cesari, M H; Juliano, L; Juliano, M A.
Afiliación
  • Del Nery E; Department of Biophysics, Escola Paulista de Medicina, UNIFESP, São Paulo, Brazil.
J Protein Chem ; 19(1): 33-8, 2000 Jan.
Article en En | MEDLINE | ID: mdl-10882170
We have determined the kinetic parameters for the hydrolysis by cathepsin B of peptidyl-coumarin amide and intramolecularly quenched fluorogenic peptides with the general structures epsilonNH2-Cap-Leu-X-MCA and Abz-Lys-Leu-X-Phe-Ser-Lys-Gln-EDDnp, respectively. Abz (orthoaminobenzoic acid) and EDDnp (2,4-dinitrophenyl-ethylenediamine) are the fluorescent donor-acceptor pair, and X was Cys(SBzl), Ser(OBzl), and Thr(OBzl) containing benzyl group (Bzl) at the functional side chain of Cys, Ser, and Thr. The peptidyl-coumarin-containing Cys(SBz1), Ser(OBzl), and Thr(OBzl) have higher affinity cathepsin B, supporting the interpretation of the crystal structure of rat cathepsin B complexed with the inhibitor Z-Arg-Ser(OBzl)-CH2Cl that the benzyl group attached to Ser hydroxyl side chain occupies the enzyme S'(1) subsite [Jia et al. (1995), J. Biol. Chem. 270, 5527]. A similar effect of benzyl group was also detected in the internally quenched peptides. Finally, the benzyl group in substrates containing Cys(SBzl) amino acid at P1 seems to compensate the absence of adequate S2-P2 interaction in the hydrolysis of the peptides having Pro or Ala at P2 position.
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Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Péptidos / Catepsina B / Aminoácidos Límite: Humans Idioma: En Revista: J Protein Chem Año: 2000 Tipo del documento: Article País de afiliación: Brasil Pais de publicación: Estados Unidos
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Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Péptidos / Catepsina B / Aminoácidos Límite: Humans Idioma: En Revista: J Protein Chem Año: 2000 Tipo del documento: Article País de afiliación: Brasil Pais de publicación: Estados Unidos