title: Substrate inhibition of cruzipain is not affected by the C-terminal domain.
abstract: Endogenous and recombinant cruzipain, the major cysteine proteinase from the protozoan parasite Trypanosoma cruzi, exhibit differences in the protein and circular dichroism spectra probably attributed to the absence of the C-terminal domain in the recombinant enzyme. Substrate hydrolysis of both molecules at 25 degrees C and neutral pH obeyed Michaelis-Menten kinetics whereas significant substrate inhibition was observed above neutral pH. The results suggest that substrate inhibition of cruzipain is pH-dependent, and that the C-terminal domain does not play an essential role in this process.
authors.affiliation: Department of Biochemistry and Molecular Biology, J. Stefan Institute, Ljubljana, Slovenia. veronika.stoka@ijs.si
authors.forename: V
authors.initials: V
authors.lastname: Stoka
authors.forename: J H
authors.initials: JH
authors.lastname: McKerrow
authors.forename: J J
authors.initials: JJ
authors.lastname: Cazzulo
authors.forename: V
authors.initials: V
authors.lastname: Turk
mesh_terms: D000818:Animals; D001665:Binding Sites; D002942:Circular Dichroism; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D009842:Oligopeptides / Q000378:metabolism; D011487:Protein Conformation; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013379:Substrate Specificity; D014349:Trypanosoma cruzi / Q000201:enzymology*
chemical_list: D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; D003546:Cysteine Endopeptidases; C063214:cruzipain