1α,24-二羟基维生素D3作用机制的研究。III. 1α,24-二羟基维生素D3与鸡甲状旁腺受体的特异性结合。

Studies on the mechanism of action of 1 alpha,24-dihydroxyvitamin D3. III. The specific binding of 1 alpha,24-dihydroxyvitamin D3 to the receptor of chick parathyroid gland.

作者信息

Ishizuka S, Bannai K, Naruchi T, Hashimoto Y

出版信息

Steroids. 1982 Jan;39(1):53-62. doi: 10.1016/0039-128x(82)90125-8.

PMID:6281950

Abstract

Three protein fractions of the cytosol of the chick parathyroid glands, which had the sedimentation constants of 2.5 S, 3.7 S and 5.5 S, were found to bind with 1 alpha,25-dihydroxyvitamin D3. Among these proteins, the 3.7 S protein was assumed to be the specific receptor protein. The 3.7 S receptor protein was also capable of binding to 1 alpha,24-dihydroxyvitamin D3 but not 25-hydroxyvitamin D3. The binding affinity of 1 alpha,24(R)-dihydroxyvitamin D3 to the 3.7 S receptor protein was estimated to be 1.2 times greater than that of 1 alpha,25-dihydroxyvitamin D3, while 1 alpha,25-dihydroxyvitamin D3 bound to the receptor protein about 10 times stronger than 1 alpha,24(S)-dihydroxyvitamin D3. The dissociation constant for the receptor-1 alpha,25-dihydroxyvitamin D3 complex at 0 degrees C was 2.7 x 10(-11) M, the dissociation constants were calculated to be 2.2 x 10(-11) M and 2.6 x 10(-10) M for the complexes with 1 alpha,24(R)-dihydroxyvitamin D3 and 1 alpha,24(S)-dihydroxyvitamin D3.

摘要

在鸡甲状旁腺细胞溶质中发现了三种蛋白质组分，其沉降常数分别为2.5S、3.7S和5.5S，它们能与1α,25 - 二羟维生素D3结合。在这些蛋白质中，3.7S蛋白质被认为是特异性受体蛋白。3.7S受体蛋白也能够与1α,24 - 二羟维生素D3结合，但不能与25 - 羟维生素D3结合。据估计，1α,24(R) - 二羟维生素D3与3.7S受体蛋白的结合亲和力比1α,25 - 二羟维生素D3高1.2倍，而1α,25 - 二羟维生素D3与受体蛋白的结合强度比1α,24(S) - 二羟维生素D3强约10倍。0℃时受体 - 1α,25 - 二羟维生素D3复合物的解离常数为2.7×10(-11)M，与1α,24(R) - 二羟维生素D3和1α,24(S) - 二羟维生素D3形成的复合物的解离常数经计算分别为2.2×10(-11)M和2.6×10(-10)M。