title: Inhibition of cruzipain, the major cysteine proteinase of the protozoan parasite, Trypanosoma cruzi, by proteinase inhibitors of the cystatin superfamily.
abstract: Cruzipain, the major cysteine proteinase from Trypanosoma cruzi epimastigotes, purified to a sequentially pure form, exists in multiple forms with pI values between 3.7 and 5.1, and an apparent molecular mass of 41 kDa. The enzyme is stable between pH 4.5-9.5. Cruzipain was found to be rapidly and tightly inhibited by various protein inhibitors of the cystatin superfamily (kass = 1.7-79 x 10(6) M-1s-1, Kd = 1.4-72 pM). These results suggest a possible defensive role for the host's cystatins after parasite infection, and may be of use for the design of new therapeutic drugs.
authors.affiliation: Department of Biochemistry and Molecular Biology, J. Stefan Institute, Ljubljana, Slovenia.
authors.forename: V
authors.initials: V
authors.lastname: Stoka
authors.forename: M
authors.initials: M
authors.lastname: Nycander
authors.forename: B
authors.initials: B
authors.lastname: Lenarcic
authors.forename: C
authors.initials: C
authors.lastname: Labriola
authors.forename: J J
authors.initials: JJ
authors.lastname: Cazzulo
authors.forename: I
authors.initials: I
authors.lastname: Björk
authors.forename: V
authors.initials: V
authors.lastname: Turk
mesh_terms: D000818:Animals; D002645:Chickens; D055312:Cystatin A; D015891:Cystatins / Q000494:pharmacology*; D003546:Cysteine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007525:Isoelectric Focusing; D007700:Kinetics; D008970:Molecular Weight; D015800:Protozoan Proteins; D011994:Recombinant Proteins / Q000494:pharmacology; D014349:Trypanosoma cruzi / Q000201:enzymology*
chemical_list: D055312:Cystatin A; D015891:Cystatins; D015800:Protozoan Proteins; D011994:Recombinant Proteins; C026407:CSTA protein, human; D003546:Cysteine Endopeptidases; C063214:cruzipain