Interaction of cystatin C variants with papain and human cathepsins B, H and L.
Recombinant human cystatin C and two of its mutants were expressed in Escherichia coli. The recombinant inhibitor was found to be identical to authentic cystatin C as judged by isoelectric focusing (pI 9.2) and kinetics of inhibition of papain and human cathepsins B, H and L. N-terminal truncation of 8 residues resulted in a decrease of isoelectric point (pI 7.8), but the inhibitory properties were similar to those of recombinant cystatin C, suggesting that Leu9 is a critical residue for the inhibition. The mutation of Trp106 to Ser, however, resulted in a decreased affinity of the inhibitor for the enzymes tested, with the largest effect on cathepsin B inhibition (approximately 100-fold increase in Ki).
Cimerman
N
N
Department of Biochemical Research and Drug Design, KRKA, d.d., Ljubljana, Slovenia. nina.cimerman@krka.si
Prebanda
M T
MT
Turk
B
B
Popovic
T
T
Dolenc
I
I
Turk
V
V
D002401:Cathepsin B / Q000037:antagonists & inhibitors; D056655:Cathepsin H; D056668:Cathepsin L; D002403:Cathepsins / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D055316:Cystatin C; D015891:Cystatins / Q000235:genetics / Q000494:pharmacology*; D003546:Cysteine Endopeptidases / Q000494:pharmacology; D015853:Cysteine Proteinase Inhibitors / Q000235:genetics / Q000494:pharmacology*; D010450:Endopeptidases; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D009154:Mutation; D010206:Papain / Q000037:antagonists & inhibitors*; D011994:Recombinant Proteins / Q000494:pharmacology; D017384:Sequence Deletion
C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors; D011994:Recombinant Proteins; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; C534281:CTSL protein, human; D056668:Cathepsin L; C534126:CTSH protein, human; D056655:Cathepsin H; D010206:Papain