Bismuth J, Castay M, Lissitzky S
Clin Chim Acta. 1976 Jun 15;69(3):417-22. doi: 10.1016/0009-8981(76)90113-3.
The reversible binding of 3,5-diiodotyrosine (DIT) to human and bovine serum protein and to purified human serum prealbumin and human and bovine albumin has been studied by equilibrium dialysis. Maximum binding occurred at pH 8.6-9.0. Human serum bound DIT less than did bovine serum. Adult ox and fetal calf sera showed similar binding. The main DIT-binding protein of human serum was prealbumin. It showed a single affinity site with a Ka of 0.85 X 10(6) M-1 at pH 8.6 and 0.40 X 10(6) M-1 at pH 7.4. The affinity constant of serum albumin for DIT was 2.8 X 10(3) M-1 at pH 8.6. The elevated binding of DIT to bovine serum is essentially due to albumin whose affinity constant for DIT is 16-times higher than that of human serum albumin. Fetuin was not responsible for any noticeable DIT binding in fetal calf serum.
通过平衡透析研究了3,5 - 二碘酪氨酸（DIT）与人及牛血清蛋白、纯化的人血清前白蛋白以及人及牛白蛋白的可逆结合。最大结合发生在pH 8.6 - 9.0。人血清结合DIT的能力低于牛血清。成年牛血清和胎牛血清表现出相似的结合情况。人血清中主要的DIT结合蛋白是前白蛋白。在pH 8.6时，它显示出一个单一的亲和位点，解离常数Ka为0.85×10⁶ M⁻¹，在pH 7.4时为0.40×10⁶ M⁻¹。血清白蛋白对DIT的亲和常数在pH 8.6时为2.8×10³ M⁻¹。DIT与牛血清结合增加主要归因于白蛋白，其对DIT的亲和常数比人血清白蛋白高16倍。胎球蛋白并非胎牛血清中显著DIT结合的原因。
