PPACK-thrombin is a noncompetitive inhibitor of α-thrombin binding to human platelets
| Autor: | Alvin H. Schmaier, F. J. Meloni, W. Nawarawong, Y. P. Jiang |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Blood Platelets
Kininogen Binding Sites Chemistry Thrombin Hematology Plasma protein binding Models Biological Amino Acid Chloromethyl Ketones Non-competitive inhibition Biochemistry Cell surface receptor Thrombin receptor medicine Humans Platelet Binding site Protein Binding circulatory and respiratory physiology medicine.drug |
| Zdroj: | Thrombosis Research. 67:479-489 |
| ISSN: | 0049-3848 |
| DOI: | 10.1016/0049-3848(92)90010-8 |
| Popis: | Recent studies from our laboratory indicate that purified kininogens are noncompetitive inhibitors of human alpha-thrombin but not PPACK-thrombin, binding to human washed platelets. In order to understand the mechanism by which the kininogens inhibit alpha-thrombin binding, investigations were initiated to determine if alpha-thrombin and PPACK-thrombin bound to the same site on human platelets. Initial investigations reveal that alpha-thrombin is a more potent inhibitor of 125I-PPACK-thrombin binding than PPACK-thrombin. Further studies show that PPACK-thrombin is a noncompetitive inhibitor of 125I-alpha-thrombin binding to platelets. These studies suggest that human alpha-thrombin binds on the platelet surface to a different site or binds differently to the same site from PPACK-thrombin. These data indicate that the ability of the kininogens to block alpha-thrombin binding to platelets but not PPACK-thrombin binding results from these thrombins having either two different binding sites or one binding site on the platelet surface which they interact with differently. |
| Databáze: | OpenAIRE |
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