Protein S enhances C4b binding protein interaction with neutrophils

Protein S enhances C4b binding protein interaction with neutrophils.

Protein S, an inhibitor of coagulation, interacts reversibly with C4b binding protein (C4bBP). The physiologic role of this complex formation remains unknown. In this study we examined the possibility that protein S would facilitate C4bBP binding to the surface of neutrophils where, in turn, this complex could help protect the cell from complement-mediated damage at the site of inflammation. Ne...

Enhancement of rabbit protein S anticoagulant cofactor activity in vivo by modulation of the protein S C4B binding protein interaction.

The carboxy-terminal region of protein S has been recently been observed to be involved in the interaction between protein S and C4b-binding protein (Walker, F. J. 1989. J. Biol. Chem. 264:17645-17658). A synthetic peptide, GVQLDLDEAI, corresponding to that region of protein S has been used to investigate the protein S/C4b-binding protein interaction in vitro and in vivo. Rabbit activated prote...

Identification of candidate residues for interaction of protein S with C4b binding protein and activated protein C.

Protein S is a plasma factor essential for prevention of thrombosis, partly due to its activity as a cofactor for the plasma anticoagulant protease-activated protein C. To expand knowledge about structure-function relationships in homologous protein S molecules, studies of protein S from different species have been performed. Protein S anti-coagulant activity in human, monkey, bovine, and porci...

Complement Inhibitor C4b-Binding Protein

C4b-binding protein (C4BP) beta-chain Short Consensus Repeat-2 specifically contributes to the interaction of C4BP with protein S.

C4b-binding protein (C4BP) regulates the complement system and the anticoagulant activity of protein S. Protein S can bind to C4BP, resulting in a decreased cofactor activity of protein S for anticoagulant activated protein C. C4BP contains several identical a-chains and a single 3-chain. Each chain contains Short Consensus Repeats (SCRs). By making chimeras of 13-chain SCRs fused to tissue-typ...