tailieunhanh - Báo cáo khóa học: Carboxydipeptidase activities of recombinant cysteine peptidases

The recombinant cysteine peptidases, cruzain from Trypanosoma cruziand fromLeishmania mexicana, are cathepsin L-like and characteristically endo-peptidases. In this study, we characterized the carboxydi-peptidase activities of these enzymes and compared them with those of human recombinant cathepsin B and cathep-sin L. The analysis used the internally quenched fluorescent peptide Abz-FRFK*-OH and some of its analogues, where Abz isortho-aminobenzoic acid and K* is (2,4-dinitrophe-nyl)-e-NH2-lysine. . | Eur. J. Biochem. 271 1046-1053 2004 FEBS 2004 doi Carboxydipeptidase activities of recombinant cysteine peptidases Cruzain of Trypanosoma cruzi and CPB of Leishmania mexicana Wagner A. S. Judice1 Luciano Puzer1 Simone S. Cotrin1 Adriana K. Carmona1 Graham H. Coombs2 Luiz Juliano1 and Maria A. Juliano1 1 Department of Biophysics Escola Paulista de Medicina Universidade Federal de Sao Paulo 04044-20 Sao Paulo Brazil 2Division of Infection and Immunity Institute of Biomedical and Life Sciences University of Glasgow UK The recombinant cysteine peptidases cruzain from Trypanosoma cruzi and from Leishmania mexicana are cathepsin L-like and characteristically endopeptidases. In this study we characterized the carboxydipeptidase activities of these enzymes and compared them with those of human recombinant cathepsin B and cathepsin L. The analysis used the internally quenched fluorescent peptide Abz-FRFK -OH and some of its analogues where Abz is ortho-aminobenzoic acid and K is 2 4-dinitrophe-nyl -e-NH2-lysine. These peptides were demonstrated to be very sensitive substrates due to the strong quenching effect of K on the fluorescence of the Abz group. The carboxydipeptidase activity of cruzain was shown to be very similar to that of cathepsin B while that of is closer to the carboxydipeptidase activity of cathepsin L. The S2 subsite architecture of cruzain and the nature of the amino acid at the P2 position of the substrates determine its carboxydipeptidase activity and gives further and direct support to the notion that the carboxydipeptidase activity of the papain family cysteine peptidases rely on the S2-P2 interaction Nagler D. K. Tam W. Storer . Krupa . Mort . Menard R. 1999 Biochemistry 38 48684874 . Cruzain and presented a broad pH-range for both the endo- and exo-peptidase activities although the later is approximately one order of magnitude lower. This feature that is not common in related