title: The propeptide of cruzipain--a potent selective inhibitor of the trypanosomal enzymes cruzipain and brucipain, and of the human enzyme cathepsin F.
abstract: Papain-like cysteine proteases of pathogenic protozoa play important roles in parasite growth, differentiation and host cell invasion. The main cysteine proteases of Trypanosoma cruzi (cruzipain) and of Trypanosoma brucei (brucipain) are validated targets for the development of new chemotherapies. These proteases are synthesized as precursors and activated upon removal of the N-terminal prodomain. Here we report potent and selective inhibition of cruzipain and brucipain by the recombinant full-length prodomain of cruzipain. The propeptide did not inhibit human cathepsins S, K or B or papain at the tested concentrations, and moderately inhibited human cathepsin V. Human cathepsin F was very efficiently inhibited (K(i) of 32 pm), an interesting finding indicating that cruzipain propeptide is able to discriminate cathepsin F from other cathepsin L-like enzymes. Comparative structural modeling and analysis identified the interaction between the beta1p-alpha3p loop of the propeptide and the propeptide-binding loop of mature enzymes as a plausible cause of the observed inhibitory selectivity.
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saude, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21949-900 Rio de Janeiro, RJ, Brazil.
authors.forename: Flavia C G
authors.initials: FC
authors.lastname: Reis
authors.forename: Tatiana F R
authors.initials: TF
authors.lastname: Costa
authors.forename: Traian
authors.initials: T
authors.lastname: Sulea
authors.forename: Alessandra
authors.initials: A
authors.lastname: Mezzetti
authors.forename: Julio
authors.initials: J
authors.lastname: Scharfstein
authors.forename: Dieter
authors.initials: D
authors.lastname: Brömme
authors.forename: Robert
authors.initials: R
authors.lastname: Ménard
authors.forename: Ana Paula C A
authors.initials: AP
authors.lastname: Lima
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D056646:Cathepsin F; D002403:Cathepsins / Q000037:antagonists & inhibitors* / Q000737:chemistry; D002460:Cell Line; D045744:Cell Line, Tumor; D002477:Cells / Q000469:parasitology; D015853:Cysteine Proteinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D004792:Enzyme Precursors / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000235:genetics; D006367:HeLa Cells; D006639:Histidine / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D008969:Molecular Sequence Data; D010843:Pichia / Q000235:genetics; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D014346:Trypanosoma brucei brucei / Q000201:enzymology*; D014349:Trypanosoma cruzi / Q000201:enzymology*
chemical_list: D015853:Cysteine Proteinase Inhibitors; D004792:Enzyme Precursors; D011994:Recombinant Proteins; D006639:Histidine; D002403:Cathepsins; C534090:CTSF protein, human; D056646:Cathepsin F