title: 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.affiliation: Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA. artbrec@bgsu.edu
authors.forename: Arthur S
authors.initials: AS
authors.lastname: Brecher
authors.forename: Amie R
authors.initials: AR
authors.lastname: Roland
mesh_terms: D000990:Antithrombin III / Q000378:metabolism*; D001797:Blood Protein Electrophoresis; D015153:Blotting, Western; D003864:Depression, Chemical; D004591:Electrophoresis, Polyacrylamide Gel; D015949:Factor IXa / Q000378:metabolism*; D006494:Heparin Antagonists / Q000494:pharmacology*; D006801:Humans; D008970:Molecular Weight; D011479:Protamines / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects
chemical_list: D006494:Heparin Antagonists; D011479:Protamines; D000990:Antithrombin III; D015949:Factor IXa