Sunnerhagen M, Drakenberg T, Forsen S, Stenflo J
Department of Physical Chemistry 2, Lund University, Malmo, Sweden.
Haemostasis. 1996;26 Suppl 1:45-53. doi: 10.1159/000217240.
Coagulation factors VII, IX, X, and protein C contain an N-terminal module with 9-12 gamma-carboxyglutamic acid (Gla) residues. It is followed by two modules that are homologous to the epidermal growth factor (EGF) and a C-terminal serine protease module. Upon calcium binding to the Gla module the side chains of three hydrophobic residues are exposed in a manner indicating that they interact with biological membranes. The calcium-binding site in the first EGF-like module appears to be required for proper orientation of the Gla and EGF-like modules relative to each other. A single calcium-binding site is also present in the serine protease module. The properties of these calcium-binding sites are briefly reviewed.
