Novel amidine-containing peptidyl phosphonates as irreversible inhibitors for blood coagulation and related serine proteases

• Published in: Journal of medicinal chemistry Vol. 37; no. 2; pp. 226 - 231
• Main Authors: Oleksyszyn, Jozef, Boduszek, Bogdan, Kam, Chih-Min, Powers, James C
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 01.01.1994; Amer Chemical Soc
• Subjects: Amidines - chemistry; Amidines - pharmacology; Amino Acid Sequence; Anticoagulants - chemistry; Anticoagulants - pharmacology; Biological and medical sciences; Blood. Blood coagulation. Reticuloendothelial system; Chemistry, Medicinal; Humans; In Vitro Techniques; Life Sciences & Biomedicine; Medical sciences; Molecular Sequence Data; Organophosphorus Compounds - chemistry; Organophosphorus Compounds - pharmacology; Pharmacology & Pharmacy; Pharmacology. Drug treatments; Science & Technology; Serine Proteinase Inhibitors - chemistry; Serine Proteinase Inhibitors - pharmacology; SELECTIVE-INHIBITION; INACTIVATION; THROMBIN INHIBITORS; DIPHENYL ESTERS; KETONE; ACID; PHOSPHONOPEPTIDES; TRYPSIN-LIKE ENZYMES; DERIVATIVES; Serine endopeptidases; Peptides; Enzyme; Coagulation; Enzyme inhibitor; Thrombin; Anticoagulant; In vitro; Biological activity; Amidine; Analog; Hydrolases; Chemical synthesis; Proteinases
• ISSN: 0022-2623; 1520-4804
• DOI: 10.1021/jm00028a004

A series of new peptidyl (alpha-aminoalkyl)phosphonate diphenyl esters containing the 4-amidinophenyl group were synthesized and tested as irreversible inhibitors,for thrombin- and other trypsin-like enzymes. These phosphonates irreversibly inhibited several coagulation enzymes and trypsin. Boc-D-Phe-Pro-(4-AmPhGly)(P)(OPh)(2) is the best human thrombin inhibitor in the series with a k(obs)/[I] value of 11 000 M(-1) s(-1), and it inhibits thrombin more than 5-fold more effectively than the other enzymes tested. Z-(4-AmPhGly)(P)(OPh)(2) is the best inhibitor for plasma kallikrein with a k(obs)/[I] value of 18 000 M(-1) s(-1). Generally, the (4-AmPhGly)(P)(OPh)(2) derivatives are better inhibitors of thrombin and trypsin than the corresponding (4-AmPhe)P(OPh)2 derivatives which contain an extra CH2 separating the amidinophenyl group from the peptide backbone. The amidino phosphonates did not inhibit acetylcholinesterase and were chemically stable in neutral buffers. In addition, the inhibited trypsin derivative did not regain any enzyme activity after removal of excess inhibitor and incubation in a pH 7.5 buffer for 1 day. Boc-D-Phe-Pro-(4-AmPhGly)(P)(OPh)(2) and D-Phe-Pro-(4-AmPhe)(P)(OPh)(2) prolonged the prothrombin time ca. 2-fold and prolonged the activated partial thromboplastin time ca. 3-4-fold in human plasma at concentrations of 63 and 125 mu M, respectively. The novel amidine-containing peptidyl phosphonates reported here are thus effective anticoagulants in vitro, and they may have utility for use in vivo.