Evidence for a reactive sulfhydryl in the DNA binding domain of the 1,25-dihydroxyvitamin D3 receptor.
Evidence for a reactive sulfhydryl in the DNA binding domain of the 1,25-dihydroxyvitamin D3 receptor.
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1,25-二羟基维生素 D3 受体 DNA 结合域中存在反应性巯基的证据。
DOI：
10.1016/0006-291x(81)90716-6
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发表时间：
1981
影响因子：
3.1
通讯作者：
Pike,JW
中科院分区：
文献类型：
--
作者：
Pike,JW
这里提出的证据表明，有机汞结合到一个反应性巯基是能够改变的1，25-二羟基维生素D受体（D-受体）的DNA结合特性。因此，HgCl 2和对氯汞苯磺酸盐（pCMBS）以浓度依赖性方式抑制无汞受体（Ro）与DNA-纤维素的结合，在1.0 mM时完全抑制明显。此外，低浓度（0.5 mM）的汞剂也能够解离预先形成的DNA-受体复合物，过量的巯基试剂（如单硫代甘油）可逆转该过程。这些发现与烷基化试剂如碘乙酰胺相反，碘乙酰胺仅能部分抑制受体-DNA双链体的形成（25 mM时为37%）。然而，一旦产生，双链体对解离完全不敏感（即使在25 mM下）。这些结果表明，除了在甾醇结合位点中或附近的半胱氨酸部分的缔合之外，类似反应性基团的修饰也可以改变D-受体的DNA结合结构域。
Evidence is presented here that organomercurial binding to a reactive sulfhydryl group is capable of altering the DNA-binding characteristics of the 1,25-dihydroxyvitamin D receptor (D-receptor). Accordingly, hormone-free receptor (Ro) binding to DNA-cellulose is inhibited in a concentration-dependent fashion with both HgCl2and p-chloromercuribenzene sulfonate (pCMBS) with complete inhibition evident at 1.0 mM. Further, low concentrations (0.5 mM) of mercurials are also capable of dissociating preformed DNA-receptor complexes, a process reversible with excess thiol reagent such as monothioglycerol. These findings are in contrast to alkylating reagents such as iodoacetamide, which is capable of only partially inhibiting the formation of the receptor-DNA duplex (37% at 25 mM). Once created, however, the duplex is completely insensitive to dissociation (even at 25 mM). These results imply that in addition to the association of a cysteine(s) moiety in or near the sterol binding site, modification of a similarly reactive group(s) can also alter the D-receptor's DNA-binding domain.