Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using enzymatic microassays, the potency of a series of new boroarginine tripeptides was determined versus thrombin and a panel of serine-proteases implicated in the coagulation and fibrinolysis pathways. The inhibition of the serine-protease complement factor I was also studied. Factor I regulates the alternate pathway of the complement and its inhibition appears to be responsible for the toxic effects of the orally available thrombin inhibitor Ac-D-Phe-Pro-boroArg (DuP-714). The structure of the new boronic acid derivatives tested was modified from that of DuP-714 by replacing the proline in the P2 position by N-cycloalkyl-glycine residues of increasing size (S18989: cyclopropyl; S18563: cyclobutyl; S18326: cyclopentyl; S18229: cyclohexyl). All compounds were found to be slow-tight binding inhibitors of thrombin versus purified human fibrinogen. Replacement of proline by N-cycloalkyl-glycines did not decrease the anti-thrombin potency of the substances up to the cyclopentyl size and this result was confirmed by classical coagulation assays with human plasma in vitro. In contrast, the inhibitory activities of the four new boronic acids were found to be lower than those of DuP-714 versus plasmin, urokinase (u-PA), plasmatic kallikrein, activated protein C (aPC) and complement factor I. The cyclopentyl derivative S18326 is a slightly more active inhibitor of thrombin than DuP-714 (initial IC50 values 3.99 +/- 0.18 nM versus 4.73 +/- 0.27 nM, respectively). Moreover S18326 was identified as the most selective compound of the series with relative potencies being 2 to 29 fold higher than that of DuP-714 versus the panel of serine-proteases tested; the rank order of potency versus the other serine-proteases for S18326 was t-PA>kallikrein>aPC>factor I>plasmin>fXa>u-PA. These results indicate that the size of the thrombin hydrophobic pocket S2 is sufficient to accept larger residues than proline in the P2 position of Ac-D-Phe-X-boroArg derivatives while this is not the case for other important serine-proteases of the fibrinolysis, coagulation and complement pathways. The N-cyclopentyl glycine containing derivative S 18326, which is the most potent and the most selective anti-thrombin compound of the series, currently undergoes major preclinical testing.
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PMID:Selection of S18326 as a new potent and selective boronic acid direct thrombin inhibitor. 936 88

DPC423, 1-[3-(aminomethyl)phenyl]-N-[3-fluoro-2'-(methylsulfonyl)[1,1'-biphenyl]-4-yl]-3-(trifluoromethyl)-1H-pyrazole-5-carboxamide, is a synthetic, orally bioavailable, competitive, and selective inhibitor of human coagulation factor Xa (K(i) [nM]: factor Xa, 0.15; trypsin, 60; thrombin, 6000; plasma kallikrein, 61; activated protein C, 1800; factor IXa, 2200; factor VIIa, >15,000; chymotrypsin, >17,000; urokinase, >19,000; plasmin, >35,000; tissue plasminogen activator, >45,000; complement factor I, 44,000 [IC(50)]). In vitro, DPC423 produced anticoagulant effects in human plasma in which it doubled prothrombin time, activated partial thromboplastin time, and Heptest clotting time at 3.1 +/- 0.4, 3.1 +/- 0.4, and 1.1 +/- 0.5 microM, respectively. In dogs, DPC423 had a good pharmacokinetic profile with an oral bioavailability of 57%, a plasma clearance of 0.24 L/kg/h, and a plasma half-life of 7.5 h. In rabbit and rat models of arteriovenous shunt thrombosis, DPC423 was an effective antithrombotic agent with an IC(50) of 150 and 470 nM, respectively. The antithrombotic effect of DPC423 is likely to be related to the inhibition of factor Xa but not to the inhibition of thrombin or due to direct inhibition of platelet aggregation. Therefore, based on potency, selectivity, efficacy, and oral bioavailability, DPC423 was selected for clinical development as an oral anticoagulant for the potential treatment of thrombotic disorders. Preliminary human data suggest that DPC423 is orally bioavailable in humans and has a long plasma half-life.
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PMID:Nonpeptide factor Xa inhibitors: DPC423, a highly potent and orally bioavailable pyrazole antithrombotic agent. 1217 91