蝗虫输卵管上血吸虫FLRF酰胺两种受体的鉴定与表征

Identification and characterization of two receptors for SchistoFLRFamide on locust oviduct.

作者信息

Wang Z, Orchard I, Lange A B

机构信息

Department of Zoology, University of Toronto, Ontario, Canada.

出版信息

Peptides. 1994;15(5):875-82. doi: 10.1016/0196-9781(94)90045-0.

DOI:10.1016/0196-9781(94)90045-0

PMID:7984508

Abstract

An in vitro binding assay, using [125I][Y1]SchistoFLRFamide (YDVDHVFLRFamide), an iodinated analogue of SchistoFLRFamide, was developed to demonstrate and characterize putative receptors for SchistoFLRFamide associated with the locust oviduct. Two receptors were revealed by the binding assay. The high-affinity receptor had a Kd of 9.52 +/- 1.15 x 10(-10) M and a Bmax of 14.5 +/- 1.2 fmol/mg membrane protein; the low-affinity receptor had a Kd of 1.86 +/- 0.16 x 10(-7) M and a Bmax of 540 +/- 43 fmol/mg membrane protein. Binding to both receptors was saturable, specific, and reversible, and competitively inhibited by [Y1]SchistoFLRFamide, SchistoFLRFamide, and ADVGHVFLRFamide. Binding was Ca2+ or Mg2+ dependent and was completely inhibited by 2 mM EDTA. The receptors showed a regional distribution, with the majority of the high-affinity receptors associated with the upper lateral oviducts, which receive little or no innervation, and most of the low-affinity receptors associated with the lower lateral and common oviducts, which receive extensive innervation.

摘要

利用[125I][Y1]血吸虫FLRF酰胺（YDVDHVFLRF酰胺），即血吸虫FLRF酰胺的碘化类似物，开展了一项体外结合试验，以证明并表征与蝗虫输卵管相关的血吸虫FLRF酰胺的假定受体。结合试验揭示了两种受体。高亲和力受体的解离常数（Kd）为9.52±1.15×10⁻¹⁰ M，最大结合量（Bmax）为14.5±1.2 fmol/mg膜蛋白；低亲和力受体的Kd为1.86±0.16×10⁻⁷ M，Bmax为540±43 fmol/mg膜蛋白。与两种受体的结合都是可饱和的、特异性的和可逆的，并且受到[Y1]血吸虫FLRF酰胺、血吸虫FLRF酰胺和ADVGHVFLRF酰胺的竞争性抑制。结合依赖于Ca²⁺或Mg²⁺，并被2 mM乙二胺四乙酸（EDTA）完全抑制。这些受体呈现出区域分布，大多数高亲和力受体与上侧输卵管相关，而上侧输卵管几乎没有或没有神经支配，大多数低亲和力受体与下侧输卵管和共同输卵管相关，而下侧输卵管和共同输卵管接受广泛的神经支配。