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Synthesis of peptides of arginine chloromethyl ketone. Selective inactivation of human plasma kallikrein

Journal Article · · Biochemistry; (United States)
DOI:https://doi.org/10.1021/bi00615a027· OSTI ID:5828301

Synthetic procedures have been developed for the preparation of peptides of arginine chloromethyl ketone and applied in the preparation of affinity labels which correspond to the -Pro-Phe-Arg- C terminus of bradykinin, a physiological cleavage site of kallikrein in kininogen. Two such reagents, Ala-Phe-ArgCH/sub 2/Cl and Pro-Phe-ArgCH/sub 2/Cl, proved to be highly effective as well as selective affinity labels for human plasma kallikrein. For example, Pro-Phe-ArgCH/sub 2/Cl inactivates plasma kallikein 50% in 24 min at a concentration of 2 x 10/sup -8/ M, while other trypsin-like proteases are less susceptible in inactivation than kallikrein, differing by a factor of 48 for plasmin and factors of 10/sup 2/ to 10/sup 5/ for factor X/sub a/, thrombin, and urokinase. The affinity of human plasma kallikrein for Ala-Phe-ArgCH/sub 2/Cl (K/sub i/ = 0.078 ..mu..M) is about 60 times that for Ala-Phe-LysCH/sub 2/Cl (K/sub i/ = 4.9 ..mu..M), whereas human plasmin exhibits about the same affinity for the former affinity label (K/sub i/ = 1.3 ..mu..M) as for the latter (K/sub i/ = 0.83 ..mu..M). The rate constants for the irreversible step of the affinity labeling reaction, k/sub 2/, are similar for all affinity labels tested with the individual proteases: 0.35 min/sup -1/ for plasma kallikrein and 0.18 min/sup -1/ for plasmin.

Research Organization:
Brookhaven National Lab., Upton, NY
OSTI ID:
5828301
Journal Information:
Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 17:22; ISSN BICHA
Country of Publication:
United States
Language:
English