Human cathepsin F: expression in baculovirus system, characterization and inhibition by protein inhibitors.
Recombinant full-length human procathepsin F, produced in the baculovirus expression system, was partially processed during the purification procedure to a form lacking the N-terminal cystatin-like domain and activated with pepsin. Active cathepsin F efficiently hydrolyzed Z-FR-MCA (kcat/Km=106 mM(-1) s(-1)) and Bz-FVR-MCA (kcat/Km=8 mM(-1) s(-1)), whereas hydrolysis of Z-RR-MCA was very slow (kcat/Km<0.2 mM(-1) s(-1)). Cathepsin F was rapidly and tightly inhibited by cystatin C, chicken cystatin and equistatin with Ki values in the subnanomolar range (0.03-0.47 nM), whereas L-kininogen was a less strong inhibitor of the enzyme (Ki=4.7 nM). Stefin A inhibited cathepsin F slowly (kass=1.6 x 10(5) M(-1) s(-1)) and with a lower affinity (Ki=25 nM). These data suggest that cathepsin F differs from other related endopeptidases by considerably weaker inhibition by stefins.
Fonovic
Marko
M
Department of Biochemistry and Molecular Biology, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
Brömme
Dieter
D
Turk
Vito
V
Turk
Boris
B
D000818:Animals; D016367:Baculoviridae / Q000235:genetics* / Q000378:metabolism; D056646:Cathepsin F; D002403:Cathepsins / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000235:genetics; D002460:Cell Line; D004789:Enzyme Activation; D015870:Gene Expression; D018014:Gene Transfer Techniques; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D011480:Protease Inhibitors / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics; D018411:Spodoptera
D011480:Protease Inhibitors; D011994:Recombinant Proteins; D002403:Cathepsins; C534090:CTSF protein, human; D056646:Cathepsin F