Related Experiment Video
Updated: Jul 29, 2026

Helical Organization of Blood Coagulation Factor VIII on Lipid Nanotubes
Published on: June 3, 2014
Soluble phosphatidylserine binds to a single identified site in the C2 domain of human factor Va
A Srivastava1, M A Quinn-Allen, S W Kim
1Department of Biochemistry and Biophysics, Program in Molecular and Cellular Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA.
Abstract:
Factor V(a) (FV(a)) is a cofactor for the serine protease factor X(a) that activates prothrombin to thrombin in the presence of Ca(2+) and a membrane surface. FV(a) is a heterodimer composed of one heavy chain (A1 and A2 domains) and one light chain (A3, C1, and C2 domains). We use fluorescence, circular dichroism, and equilibrium dialysis to demonstrate that (1) the FV C2 domain expressed in Sf9 cells binds one molecule of C6PS with a k(d) of approximately 2 microM, (2) stabilizing changes occur in the FV C2 domain upon C6PS binding, (3) the C6PS binding site in the FV C2 domain is located near residue Cys(2113), which reacts with DTNB, and (4) binding to a PS-containing membrane is an order of magnitude tighter than that to soluble C6PS. Coupled with a recently published crystal structure of the C2 domain, these results support a model for the mechanism of C2-membrane interaction.
More Related Videos
08:49Fluorescence-Based Measurements of Phosphatidylserine/Phosphatidylinositol 4-Phosphate Exchange Between Membranes
Published on: March 14, 2021
10:31A Liposome Membrane Permeability Assay for Investigating the Effects of Phosphatidylinositol Phosphate Groups on Membranotropic Action of Venom PLA2
Published on: September 26, 2025
Related Concept Videos
Lipids as Anchors
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
Membrane Domains
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior...
Phosphoinositides and PIPs
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Coat Assembly and GTPases
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Synthesis of Phosphatidylcholine in the ER Membrane
The major components of all eukaryotic cell...
Intracellular Signaling Affects Focal Adhesions
Some...