Plasmin-mediated proteolysis of human factor IXa in the presence of calcium/phospholipid: Conversion of procoagulant factor IXa to a fibrinolytic enhancer.

ABSTRACT:

Background

Factor (F) IX/IXa inactivation by plasmin has been studied; however, whether plasmin converts FIXa to a fibrinolytic enhancer is not known.

Objective

Investigate plasmin proteolysis site(s) in FIXa that inactivates and transforms it into a fibrinolytic enhancer.

Methods

NH₂ -terminal sequencing, mass spectrometry analysis, and functional assays.

Results

Plasmin in the presence of Ca²⁺ /phospholipid (PL) rapidly cleaved FIXaβ at Lys316↓Gly317 to yield FIXaγ followed by a slow cleavage at Lys413↓Leu414 to yield FIXaδ. FIXaγ/FIXaδ migrated indistinguishably from FIXaβ in nondenaturing gel system indicating that C-terminal residues 317-415/317-413 of heavy chain remain noncovalently associated with FIXaγ/FIXaδ. However, as compared

SUBMITTER: Schmidt AE 

PROVIDER: S-EPMC7363452 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature