The first EGF-like domain from human factor IX contains a high-affinity calcium binding site.

摘要: It has been suggested that epidermal growth factor-like (EGF-like) domains, containing conserved carboxylate residues, are responsible for the high-affinity calcium binding exhibited by a number of vitamin K-dependent plasma proteins involved in control blood coagulation cascade. These include procoagulant factors IX and X, anticoagulants protein C S. To test this hypothesis we have expressed first EGF-like domain from human factor (residues 46-84) using yeast secretion system, examined to domain. Using 1H-NMR measure calcium-dependent shift assigned Tyr69 detected site (Kd = 200-300 microM). We suggest other domains type may similar properties. In addition, completely aromatic region NMR spectrum NOESY COSY analysis, used these data discuss effect pH on conformation with reference model based structure EGF.