Design and evaluation of inhibitors for dipeptidyl peptidase I (Cathepsin C).
Dipeptidyl peptidase I (DPPI, cathepsin C) is a lysosomal cysteine protease that can activate zymogens of several different serine proteases by one step or sequential removal of dipeptides from the N-termini of the pro-protease protein substrates. To find DPPI inhibitors more suitable for cellular applications than diazomethyl ketones, we synthesized three types of inhibitors: dipeptide acyloxymethyl ketones, fluoromethyl ketones, and vinyl sulfones (VS). The acyloxymethyl ketones inhibited DPPI slowly and are moderate inhibitors of cellular DPPI. The fluoromethyl ketones were potent, but the inhibited DPPI regained activity quickly. The dipeptide vinyl sulfones were effective inhibitors for DPPI, but they also inhibited cathepsins B, H, and L weakly. The best inhibitor, Ala-Hph-VS-Ph, had a k2/K(I) of 2,000,000M(-1)s(-1). The vinyl sulfones also inhibited intracellular DPPI, and for this application the more stable inhibitors exhibit better potency. We conclude that vinyl sulfones are promising inhibitors to study the intracellular functions of DPPI.
Kam
Chih-Min
CM
School of Chemistry and Biochemistry and the Petit Institute for Bioscience and Bioengineering, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA.
Götz
Marion G
MG
Koot
Gretchen
G
McGuire
Michael
M
Thiele
Dwain
D
Hudig
Dorothy
D
Powers
James C
JC
D000818:Animals; D020789:Cathepsin C / Q000037:antagonists & inhibitors* / Q000737:chemistry; D002460:Cell Line; D015195:Drug Design; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000138:chemical synthesis; D006801:Humans; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry*; D008407:Mast Cells / Q000201:enzymology; D051381:Rats; D013154:Spleen / Q000201:enzymology; D013450:Sulfones / Q000138:chemical synthesis / Q000737:chemistry*
D004791:Enzyme Inhibitors; D007659:Ketones; D013450:Sulfones; C009873:divinyl sulfone; D020789:Cathepsin C