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

Author Chagas, JR Google Scholar
Authie, E. Google Scholar
Serveau, C. Google Scholar
Lalmanach, G. Google Scholar
Juliano, L. Google Scholar
Gauthier, F. Google Scholar
Institution UNIV TOURS
ILRI
Universidade Federal de São Paulo (UNIFESP)
Abstract 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.
Keywords Trypanosoma congolense
Trypanosoma cruzi
cysteine proteinase
cystatin
Language English
Date 1997-09-01
Published in Molecular and Biochemical Parasitology. Amsterdam: Elsevier B.V., v. 88, n. 1-2, p. 85-94, 1997.
ISSN 0166-6851 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 85-94
Origin http://dx.doi.org/10.1016/S0166-6851(97)00085-6
Access rights Closed access
Type Article
Web of Science ID WOS:A1997XR36500009
URI http://repositorio.unifesp.br/handle/11600/25785

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