The roles of factor Va and protein S in formation of the activated protein C/protein S/factor Va inactivation complex.

ABSTRACT:

Background

Activated protein C (APC)-mediated inactivation of factor (F)Va is greatly enhanced by protein S. For inactivation to occur, a trimolecular complex among FVa, APC, and protein S must form on the phospholipid membrane. However, direct demonstration of complex formation has proven elusive.

Objectives

To elucidate the nature of the phospholipid-dependent interactions among APC, protein S, and FVa.

Methods

We evaluated binding of active site blocked APC to phospholipid-coated magnetic beads in the presence and absence of protein S and/or FVa. The importance of protein S and FV residues were evaluated functionally.

Results

Activated protein C alone bound weakly to phospholipids. Protein S mildly enhanced APC binding to phospholipid surfaces, whereas FVa d

SUBMITTER: Gierula M 

PROVIDER: S-EPMC6916587 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature