由紫外光谱法测定蛋白质浓度,用ICP测定Ca含量,从而确定一个ACF分子中含一个钙离子.ACF中分子中除一个高亲和性钙结合位点外,至少还有一个低亲和性钙结合位点,只有当过量钙离子存在时,才可能在低亲和性钙结合位点上进一步结合钙离子.Tb~(3+)具有比Ca~(2+)离子更强的键合ACF能力,能定量结合在ACF中的两个位点上,且能全部取代ACF中Ca~(2+).文中提及的金属离子对ACF的抗凝血活性没有显著的影响. The protein concentration was determined by UV spectrophotometry and the Ca content was determined by ICP to determine the presence of one calcium ion in an ACF molecule.In addition to a high-affinity calcium binding site in the molecule of ACF at least one low-affinity calcium Binding site, it is possible to further bind calcium ions at low affinity calcium binding sites only in the presence of an excess of calcium ions.Tb ~ (3+) has a stronger bound ACF than Ca ~ (2+) ions Ability to bind quantitatively to two sites in ACF and completely replace Ca 2+ in ACF.The metal ions mentioned in this paper have no significant effect on anticoagulant activity of ACF.