Send to

Choose Destination
Blood Coagul Fibrinolysis. 2011 Jun;22(4):247-53. doi: 10.1097/MBC.0b013e328343f93f.

Protamine sulfate stimulates degradation of factor Xa and the factor Xa-antithrombin complex.

Author information

Departments of Biological Sciences and Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA.


The effect of protamine sulfate on factor Xa (FXa) and the factor Xa-antithrombin complex was studied via SDS-PAGE and Western blot analysis. Human factor Xa [(FXaα) ∼52 kDa, FXaβ ∼47 kDa] and human antithrombin (AT ∼55 kDa) form a primary (1°) complex at 109 and 104 kDa, a secondary (2°) complex at 99 and 95 kDa, and a tertiary (3°) complex at 66 and 62 kDa, as detected with polyclonal anti-FXa and anti-AT antibodies. Addition of protamine sulfate stimulates a transformation from free FXaα to FXaβ and degradation thence to inactive FXaγ (∼30 kDa), as well as transformation of FXaα-AT complexes to FXaβ-AT complexes. Additionally, protamine sulfate promotes digestive degradation from 1° to 3° complexes and FXaγ by the active enzyme. It further promotes reduction in total complex formation as a function of stimulation of hydrolysis of FXa moieties from the complex, thereby generating ATM. Protamine sulfate effects are proportional to the protamine sulfate concentration.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wolters Kluwer
Loading ...
Support Center