软体动物鳃中降钙素基因相关肽结合位点的表征

Characterization of binding sites for calcitonin gene-related peptide in the mollusc gill.

作者信息

Fouchereau-Peron M

机构信息

Unité de Recherches Marines, URM 14, Collège de France, Concarneau, France.

出版信息

Regul Pept. 1996 Jan 16;61(1):57-61. doi: 10.1016/0167-0115(95)00138-7.

DOI:10.1016/0167-0115(95)00138-7

PMID:8701028

Abstract

Target organs for calcitonin gene-related peptide (CGRP) were investigated in Pecten maximus using 125I-labelled human CGRP. CGRP was shown to interact specifically with mantle and gill tissue. Receptor studies using branchial membrane preparations indicated that the binding was time dependent. Scatchard analysis of binding data showed that there was a single class of binding sites. The affinity constant was found to be 0.7.10(8) M-1 and the number of binding sites 2600.10(8)/mg of protein. Salmon CT inhibited the binding of 125I-labelled CGRP to branchial membranes with a lesser efficiency than that of the unlabelled hormone. A 40% inhibition of the 125I-labelled CGRP binding was observed in the presence of 2.6 and 26 nM CGRP and salmon CT, respectively. In addition, 200 nM human CGRP inhibited 25 and 10% of the basal branchial and mantle adenylate cyclase activity, respectively. These data suggest that CGRP participates in the regulation of the branchial function in molluscs probably via a vasoconstrictor role.

摘要

使用¹²⁵I标记的人降钙素基因相关肽（CGRP），在大扇贝中研究了CGRP的靶器官。结果显示CGRP与外套膜和鳃组织有特异性相互作用。使用鳃膜制剂进行的受体研究表明，结合具有时间依赖性。对结合数据进行Scatchard分析表明存在单一类别的结合位点。发现亲和常数为0.7×10⁸ M⁻¹，结合位点数量为2600×10⁸/毫克蛋白质。鲑鱼降钙素抑制¹²⁵I标记的CGRP与鳃膜结合的效率低于未标记的激素。在分别存在2.6 nM和26 nM CGRP及鲑鱼降钙素的情况下，观察到¹²⁵I标记的CGRP结合分别被抑制40%。此外，200 nM人CGRP分别抑制基础鳃和外套膜腺苷酸环化酶活性的25%和10%。这些数据表明，CGRP可能通过血管收缩作用参与软体动物鳃功能的调节。