Protamine inhibits formation of the covalent factor IXa-anti-thrombin complex.

Abstract

The effect of protamine sulfate upon the covalent interaction of human factor IXa with anti-thrombin has been investigated by a quantitative SDS-polyacrylamide gel electrophoresis procedure. Protamine sulfate inhibits the interaction of factor IXa with anti-thrombin upon preincubation with factor IXa, anti-thrombin, or a mixture of the two components. As a consequence of the presence of protamine sulfate, autolysis of factor IXa is promoted to generate a degradation product of a molecular weight (apparent) of 35 kDa. Concomitantly, free factor IXa and free anti-thrombin levels are increased in the mixture. In contrast to the effect of protamine sulfate, heparin promotes a massive increase in the factor IXa-anti-thrombin complex appearing as a doublet. Associated with the increase in the complex is a precipitous drop in free factor IXa and anti-thrombin, as well as the steep decline in the 35 kDa factor IX fragment, the presence of which reflects the degradation of factor IXa. Accordingly, protamine sulfate appears to exert a procoagulant effect upon addition to an intrinsic coagulation system enzyme, in contrast to its modest anticoagulant effect on the overall coagulation process.

• Authors: Arthur S Brecher, Amie R Roland
• Journal: Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis (Blood Coagul Fibrinolysis) Vol. 19 Issue 6 Pg. 591-6 (Sep 2008) ISSN: 0957-5235 [Print] England
• PMID: 18685444 (Publication Type: Journal Article)

Chemical References

• Heparin Antagonists
• Protamines
• Antithrombin III
• Factor IXa

Topics

• Antithrombin III (metabolism)
• Blood Protein Electrophoresis
• Blotting, Western
• Depression, Chemical
• Electrophoresis, Polyacrylamide Gel
• Factor IXa (metabolism)
• Heparin Antagonists (pharmacology)
• Humans
• Molecular Weight
• Protamines (pharmacology)
• Protein Binding (drug effects)