Establishing the inhibitory effects of bradykinin on thrombin

Cleary, David B.; Ehringer, William D.; Maurer, Muriel C.

doi:10.1016/s0003-9861(02)00677-x

Cited by 7 publications

(5 citation statements)

References 42 publications

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“…The inhibitory properties of bradykinin map to the peptide RPPGF, a naturally occurring biological peptide that is the terminal ACE breakdown product of bradykinin [16]. Bradykinin, RPPGF and analogs inhibit platelet activation by two mechanisms: they bind to the active site of thrombin and to the exodomain of PAR1 at the thrombin cleavage site [11,16,17]. The present report expands the thrombin inhibitory mechanism of RPPGF and related compounds by showing that they also bind to the exodomain of PAR4.…”

Section: Discussionmentioning

confidence: 54%

Mapping the interaction of bradykinin 1–5 with the exodomain of human protease activated receptor 4

et al. 2004

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The angiotensin converting enzyme breakdown product of bradykinin, bradykinin 1-5 (RPPGF), inhibits thrombininduced human or mouse platelet aggregation. RPPGF binds to the exodomain of human protease-activated receptor 1 (PAR1). Studies determined if RPPGF also binds to the exodomain of human PAR4. RPPGF binds to a peptide of the thrombin cleavage site on PAR4. Recombinant wild-type and mutated exodomain of human PAR4 was prepared. The N-terminal arginine on RPPGF binds to the P2 position or proline 46 on PAR4 to block thrombin cleavage. These data indicate that RPPGF influences thrombin activity by binding to the thrombin cleavage site on both PAR4 and PAR1.

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Section: Discussionmentioning

confidence: 54%

Mapping the interaction of bradykinin 1–5 with the exodomain of human protease activated receptor 4

et al. 2004

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“…Since bradykinin, RPPGF, and TH146 ( K i = 97 μ m ) bind directly to the active site of thrombin to interfere with its enzymatic activity [6,7,18], investigations determined the concentration of the FM compounds required to inhibit α‐thrombin. FM19 was a direct competitive inhibitor of α‐thrombin with a K i of 4.4 ± 2.4 μ m (Fig.…”

Section: Resultsmentioning

confidence: 99%

Thrombostatin FM compounds: direct thrombin inhibitors – mechanism of action in vitro and in vivo

Nieman

Burke²,

Warnock³

et al. 2008

Journal of Thrombosis and Haemostasis

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Mosberg HI, Schmaier AH. Thrombostatin FM compounds: direct thrombin inhibitors -mechanism of action in vitro and in vivo. J Thromb Haemost 2008; 6: 837-45.Summary. Background: Novel pentapeptides called Thrombostatin FM compounds consisting mostly of D-isomers and unusual amino acids were prepared based upon the stable angiotensin converting enzyme breakdown product of bradykinin -RPPGF. Methods and Results: These peptides are direct thrombin inhibitors prolonging the thrombin clotting time, activated partial thromboplastin time, and prothrombin time at ‡0.78, 1.6, and 1.6 lM, respectively. They competitively inhibit a-thrombin-induced cleavage of a chromogenic substrate at 4.4-8.2 lM. They do not significantly inhibit plasma kallikrein, factor (F) XIIa, FXIa, FIXa, FVIIa-TF, FXa, plasmin or cathepsin G. One form, FM19 [rOicPaF(p-Me)], blocks athrombin-induced calcium flux in fibroblasts with an IC 50 of 6.9 ± 1.2 lM. FM19 achieved 100% inhibition of threshold aor c-thrombin-induced platelet aggregation at 8.4 ± 4.7 lM and 16 ± 4 lM, respectively. The crystal structure of thrombin in complex with FM19 shows that the N-terminal D-Arg retrobinds into the S1 pocket, its second residue Oic interacts with His-57, Tyr-60a and Trp-60d, and its C-terminal p-methyl Phe engages thrombinÕs aryl binding site composed of . When administered intraperitoneal, intraduodenal, or orally to mice, FM19 prolongs thrombin clotting times and delays carotid artery thrombosis. Conclusion: FM19, a low affinity reversible direct thrombin inhibitor, might be useful as an add-on agent to address an unmet need in platelet inhibition in acute coronary syndromes in diabetics and others who with all current antiplatelet therapy still have reactive platelets.

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“…Because RPPGF and bradykinin interact with the active site of thrombin, investigations were performed to determine the kinetics of TH146 and MAP4TH146 inhibition of thrombin and to ascertain whether these peptides inhibit the enzymatic activity of any other coagulation enzyme(s) ( Table 2) (Cleary et al, 2003;Hasan et al, 2003). TH146 and MAP4-TH146 inhibited human ␣-thrombin hydrolysis of Sar-ProArg-pNA with a K i value of 9.7 Ϯ 2.8 ϫ 10 Ϫ5 and 4.9 Ϯ 1.8 ϫ 10 Ϫ5 M, respectively (Table 2).…”

Section: Resultsmentioning

confidence: 99%

The Preparation and Characterization of Novel Peptide Antagonists to Thrombin and Factor VIIa and Activation of Protease-Activated Receptor 1

Nieman¹,

Warnock²,

Hasan³

et al. 2004

J Pharmacol Exp Ther

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Thrombin and protease-activated receptor 1 (PAR1) activation antagonists were prepared based upon the peptide RPPGF, the angiotensin-converting enzyme breakdown product of bradykinin. A library of 72 peptides consisting of D and/or synthetic amino acids was designed with various substitutions in positions 1 to 5 in Arg-Pro-Pro-Gly-Phe (RPPGF). Two compounds, rOicPGF (TH146) and ␤AK2K-4(rOicPGF) (MAP4-TH146), were characterized further. TH146 or MAP4-TH146 completely inhibits threshold ␥-thrombin-induced platelet aggregation at a concentration of 142 Ϯ 0.05 or 19 Ϯ 0.06 M, respectively. TH146 completely inhibits threshold ␣-thrombin-induced washed platelet aggregation at 444 Ϯ 0.04 M. TH146 or MAP4-TH146 blocks 2 nM ␣-thrombin-induced fibroblast calcium mobilization with an IC 50 value of 110 or 18 M, respectively. Furthermore, significant prolongation of the activated partial thromboplastin time, prothrombin time, or thrombin clotting time occurs at 31, 62, or 7.8 M TH146 and 0.4, 6.25, or 1.56 M MAP4-TH146, respectively. TH146 and MAP4-TH146 inhibit both ␣-thrombin with a K i value of 97 and 49 M, respectively, and factor VIIa with a K i value of 44 and 5 M, respectively. Both TH146 and MAP4-TH146 specifically bind to the exodomain of recombinant PAR1. MAP4-TH146 (200 M) completely blocks thrombocytin, a PAR1-activating snake venom protease, without inhibiting the enzyme's active site. TH146 inhibits ␥-thrombin-induced aggregation of mouse platelets, prolongs mouse bleeding times, and delays the time to mouse carotid artery thrombosis. TH146 and MAP4-TH146 inhibit human and mouse platelet aggregation and mouse thrombosis. Analogs of RPPGF are model compounds to develop PAR1 activation antagonists as well as direct inhibitors to thrombin and factor VIIa.Investigations from a number of laboratories indicate that platelet receptors for thrombin are antiplatelet targets. Hanson and Harker (1988) showed that treatment of baboons with Phe-Pro-Arg-chloromethylketone, a potent direct acting thrombin inhibitor, prolongs the bleeding time. More recently, knockout mice of protease-activated receptor (PAR) 3 or 4, mouse platelet thrombin receptors, independently prolong bleeding times and are protected against ferric chlorideinduced thrombosis (Weiss et al., 2002). Cook et al. (1995) showed that an IgG raised to a peptide of the hirudin-anionic binding region on the exosite of human PAR1 reduces or abolishes cyclic flow variations in the carotid artery of monkeys. A nonpeptide mimetic (RWJ-58259) directed to the cleaved PAR1 activation site after a 3 mg/kg intravenous bolus followed by a constant infusion of 0.123 mg/kg/min significantly prolongs the time to carotid artery thrombosis in monkeys (Derian et al., 2003). Furthermore, another nonpeptide mimetic at 1 mg/kg directed to the SFLLRN activation site on PAR1 delays the time to guinea pig carotid artery thrombosis (Kato et al., 2003). These combined studies indicate that inhibition of thrombin, thrombin binding to PAR1, and/or PAR1 activation prolongs the bleed...

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Establishing the inhibitory effects of bradykinin on thrombin

Cited by 7 publications

References 42 publications

Mapping the interaction of bradykinin 1–5 with the exodomain of human protease activated receptor 4

Mapping the interaction of bradykinin 1–5 with the exodomain of human protease activated receptor 4

Thrombostatin FM compounds: direct thrombin inhibitors – mechanism of action in vitro and in vivo

The Preparation and Characterization of Novel Peptide Antagonists to Thrombin and Factor VIIa and Activation of Protease-Activated Receptor 1

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