Roy P, Naik U, Sen I
Department of Medicine, Cornell University Medical College, New York, NY 10021.
Biochem Biophys Res Commun. 1988 May 31;153(1):1-6. doi: 10.1016/s0006-291x(88)81181-1.
Multiple forms of atrial natriuretic factor receptor have been identified in human placental membranes. Atrial natriuretic factor binds specifically to placental membranes and the binding activity could be solubilized using non ionic detergent, Triton X-100. Binding to the detergent solubilized preparation was inhibited 80% by the addition of 0.5 M sodium chloride. Affinity cross-linking analysis indicated that this binding was associated with a single protein band of molecular weight 170-kDa. On the other hand, if sodium chloride was added together with a chelator, o-phenanthroline, ANF binding to this preparation was stimulated 300%. Binding under these conditions was not to the 170-kDa protein but was associated with a broad band in the region of 100/110-kDa and a minor band at 200-kDa. These observations clearly indicated that in human placental membranes, atrial natriuretic factor binds to distinctly different molecular species depending on the presence or absence of certain ions and chelators. The two types of binding could be conveniently assayed in the presence of each other by elimination or inclusion of sodium chloride and o-phenanthroline in the assay system.
在人胎盘膜中已鉴定出多种形式的心房利钠因子受体。心房利钠因子特异性结合胎盘膜，且结合活性可用非离子去污剂Triton X - 100溶解。加入0.5M氯化钠可使与去污剂溶解制剂的结合抑制80%。亲和交联分析表明，这种结合与一条分子量为170 kDa的单一蛋白带相关。另一方面，如果氯化钠与螯合剂邻菲罗啉一起加入，心房利钠因子与该制剂的结合会被刺激300%。在这些条件下的结合不是与170 kDa的蛋白结合，而是与100/110 kDa区域的一条宽带和200 kDa处的一条小带相关。这些观察结果清楚地表明，在人胎盘膜中，心房利钠因子根据某些离子和螯合剂的存在与否，与截然不同的分子种类结合。通过在测定系统中排除或加入氯化钠和邻菲罗啉，可方便地在彼此存在的情况下测定这两种结合类型。
