SYNTHESIS AND KINETIC-STUDIES OF DIPHENYL 1-(N-PEPTIDYLAMINO)ALKANEPHOSPHONATE ESTERS AND THEIR BIOTINYLATED DERIVATIVES AS INHIBITORS OF SERINE PROTEASES AND PROBES FOR LYMPHOCYTE GRANZYMES

Diphenyl 1-(N-peptidylamino)alkanephosphonate esters are highly reacti ve, specific, and aqueously stable irreversible inhibitors which can b e used to probe the functions of many serine proteases, including. the lymphocyte granzymes. We synthesized 16 peptide phosphonates with Ala , Met, Phe, or Val pi amino acid residues, including two biotinylated derivatives for future functional and biochemical characterization of granzymes, The reactivity of the inhibitors was characterized with hum an leukocyte elastase (HLE), porcine pancreatic elastase (PPE), bovine chymotrypsin, and the granzymes of natural killer (NK) cells, which i nclude a number of proteolytic activities (Asp-ase, Met-ase, etc.) tha t cleave peptide substrates with these residues in the P1 position, Th e reactivity and specificity of the phosphonates depended on the lengt h and sequence of the peptidyl moiety and on the leaving group. Z-Ala- Ala-Ala(P)(OPh)(2) was a good inhibitor of HLE and PPE (k(obsd)/[I] = 38 and 30 M-1 s(-1), respectively) and had little reactivity with chym otrypsin. Z-Phe-Pro-Phe(P)(OPh)(2) was a good inhibitor of chymotrypsi n (k(obsd)/[I] = 17,000 m(-1)s(-1)) and had little reactivity with the elastases, The leaving group of Z-Met(P)(OPh-4-Cl)(2) made it a more effective chymotrypsin inhibitor than Z-Met(P)(OPh)(2) (k(obsd)/[I] va lues of 142 and 30 M(-1)s(-1), respectively), With granzymes, the comp ounds reacted with a fraction of the Met-ase, chymase, and Ser-ase act ivities and lacked reactivity with Asp-ase and tryptase. Z-Met(P)(OPh- 4-Cl)(2) was an excellent inhibitor of Met-ase 1. Bi-Aca-Aca-Phe-Leu-P he(P)(OPh)(2) appears to react specifically with one chymase while lea ving other chymases untouched. Perforin-dependent lysis mediated by cy totoxic lymphocyte granules was inactivated by Z-Ala-Ala-AZa(P)(OPh)(2 ), Z-Met(P)(OPh-4-Cl)(2), Z-Leu-Phe(P)(OPh)(2), and Bi-Aca-Aca-Phe-Leu -Phe(P)(OPh)(2). The biochemical properties and biological efficacy of these inhibitors make them suitable for cellular and physiological st udies of granzyme function. (C) 1997 Academic Press.