Duncan P H, Wills M R, Smith B J, Savory J
Clin Chem. 1982 Apr;28(4 Pt 1):672-5.
A recently developed gel-filtration technique allows protein-bound calcium fractions to be separated and quantitated; the protein is separated under physiological conditions of pH, temperature, and concentrations of Na, Mg, and Ca to assure that the calcium-proteinate equilibrium is not disturbed. We used this gel-filtration technique to study the protein-bound calcium fractions in 18 patients with hyperparathyroidism, multiple myeloma, diabetes, osteoporosis, or liver cirrhosis. We calculated the amount of calcium bound per gram of protein for each of the three protein peaks and the intrinsic association constant (Ka) for calcium/albumin. Results with the multiple myeloma patients (three IgG, one IgA) indicated that IgG did not bind calcium appreciably, that IgA had about the same affinity as albumin for Ca, and that Ka was slightly low for one patient of the IgG type (79 L/mol) and normal for the other three myeloma patients (106, 90, and 91 L/mol). Results for patients with the other diseases were also essentially normal, except for the osteoporesis patients (two men, one woman), whose Ka values (69, 75, and 73 L/mol) were lower than normal.
最近开发的一种凝胶过滤技术可对与蛋白质结合的钙组分进行分离和定量；蛋白质在pH、温度以及钠、镁和钙浓度的生理条件下进行分离，以确保钙 - 蛋白质酸盐平衡不受干扰。我们使用这种凝胶过滤技术研究了18例甲状旁腺功能亢进、多发性骨髓瘤、糖尿病、骨质疏松症或肝硬化患者的与蛋白质结合的钙组分。我们计算了三个蛋白质峰中每克蛋白质结合的钙量以及钙/白蛋白的内在缔合常数（Ka）。多发性骨髓瘤患者（3例IgG型、1例IgA型）的结果表明，IgG与钙的结合不明显，IgA对钙的亲和力与白蛋白大致相同，1例IgG型患者的Ka略低（79 L/mol），其他3例骨髓瘤患者的Ka正常（106、90和91 L/mol）。除骨质疏松症患者（2名男性、1名女性）外，其他疾病患者的结果基本正常，这些骨质疏松症患者的Ka值（69、75和73 L/mol）低于正常水平。
