1α,24-二羟基维生素D3作用机制的研究。II. α,24-二羟基维生素D3与鸡肠受体的特异性结合。

Studies on the mechanism of action of 1 alpha, 24-dihydroxyvitamin D3. II. Specific binding of alpha, 24-dihydroxyvitamin D3 to chick intestinal receptor.

作者信息

Ishizuka S, Bannai K, Naruchi T, Hashimoto Y

出版信息

Steroids. 1981 Jan;37(1):33-43. doi: 10.1016/0039-128x(81)90005-2.

Abstract

The binding of vitamin D3 analogues to the chick intestinal cytosol receptor was studied. In intestinal cytosol fraction, receptor proteins having the sedimentation constant of 2.5 S and 3.7 S to which 1 alpha,25-dihydroxyvitamin D3 binds were present, and the latter was specific for the compound. The binding of 1 alpha,24(R)-dihydroxyvitamin D3 and 1 alpha,24(S)-dihydroxyvitamin D3 to the receptor was also observed, while very weak binding was seen in the case of 24(R)25-dihydroxyvitamin D3 and 25-hydroxyvitamin D3. The binding affinity of 1 alpha,24(R)-dihydroxyvitamin D3 to the 3.7 S receptor was 1.3 times as high as that of 1 alpha,25-dihydroxyvitamin D3, whereas those of 1 alpha,24(S)-dihydroxyvitamin D3, 1 alpha-hydroxyvitamin D3 and 25-hydroxyvitamin D3 were 10, 304 and 652 times lower than 1 alpha,25-dihydroxyvitamin D3, respectively. The dissociation constant of the receptor-1 alpha,25-dihydroxyvitamin D3 complex at 0 degrees C was 3.0 x 10(-11) M, and the dissociation constants were calculated to be 2.4 x 10(-11) M and 2.7 x 10(-10) M for the complexes with 1 alpha,24(R)-dihydroxyvitamin D3 and 1 alpha,24(S)-dihydroxyvitamin D3, respectively.

摘要

研究了维生素D3类似物与鸡肠细胞溶质受体的结合情况。在肠细胞溶质部分，存在沉降常数为2.5S和3.7S的受体蛋白，1α,25 - 二羟基维生素D3可与之结合，且后者对该化合物具有特异性。还观察到1α,24(R)-二羟基维生素D3和1α,24(S)-二羟基维生素D3与受体的结合，而24(R)25 - 二羟基维生素D3和25 - 羟基维生素D3的结合非常弱。1α,24(R)-二羟基维生素D3与3.7S受体的结合亲和力是1α,25 - 二羟基维生素D3的1.3倍，而1α,24(S)-二羟基维生素D3、1α - 羟基维生素D3和25 - 羟基维生素D3的结合亲和力分别比1α,25 - 二羟基维生素D3低10、304和652倍。受体 - 1α,25 - 二羟基维生素D3复合物在0℃时的解离常数为3.0×10(-11)M，与1α,24(R)-二羟基维生素D3和1α,24(S)-二羟基维生素D3形成的复合物的解离常数经计算分别为2.4×10(-11)M和2.7×10(-10)M。