Presence in brain of synenkephalin, a proenkephalin-immunoreactive protein which does not contain enkephalin
Presence in brain of synenkephalin, a proenkephalin-immunoreactive protein which does not contain enkephalin
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大脑中存在脑啡肽，一种不含脑啡肽的脑啡肽原免疫反应蛋白
作者：
D. Liston;J. Vanderhaeghen;J. Rossier
肾上腺脑啡肽原的一级序列最近有三个研究组1 -3报道，他们分离并测序了该激素原的cDNA。在脑啡肽原的加工过程中，含有1 - 4个[Met]脑啡肽拷贝的几种中间体已从肾上腺髓质中纯化出来4 -9。虽然有证据表明脑和肾上腺髓质中的脑啡肽原是相同的，但尚未从脑中分离出类似的中间体。我们在这里报告生产的抗血清直接针对一个纯化的脑啡肽前体来自肾上腺脑啡肽原的氨基末端，与抗原在大脑中的交叉反应。脑内的免疫反应蛋白不含脑啡肽序列，但在免疫组织化学研究中显示与脑啡肽平行的分布模式。在牛尾壳核提取物中，该抗原的摩尔浓度约为[Met]脑啡肽的五分之一。结果表明，抗血清识别肾上腺脑啡肽原N-末端72个氨基酸残基内的抗原决定簇，脑中的脑啡肽前体与肾上腺髓质中发现的类似。此外，脑蛋白中脑啡肽序列的缺失表明脑啡肽原加工过程中较大中间体的浓度在脑中比在肾上腺髓质中低得多。
The primary sequence of adrenal proenkephalin has recently been reported by three groups1–3 who have isolated and sequenced the cDNA for this prohormone. Several intermediates in the processing of proenkephalin, containing from one to four copies of [Met]enkephalin, have been purified from the adrenal medulla4–9. Although there is evidence that the proenkephalin is identical in the brain and the adrenal medulla, similar intermediates have not been isolated from brain. We report here the production of an antiserum directed against a purified enkephalin precursor derived from the amino terminus of adrenal proenkephalin which cross-reacts with an antigen in brain. The immunoreactive protein in brain does not contain the sequence of enkephalin, but shows a pattern of distribution in immunohistochemical studies parallel to that of the enkephalins. In extracts of bovine caudate-putamen, this antigen is present in a molar concentration approximately one-fifth of that of [Met]enkephalin. The results demonstrate that the antiserum recognizes antigenic determinants within the N-terminal 72 amino acid residues of adrenal proenkephalin and that the enkephalin precursor in brain is similar to that found in the adrenal medulla. Furthermore, the absence of the enkephalin sequence in the brain protein indicates that concentrations of the larger intermediates in the processing of proenkephalin are much lower in the brain than in the adrenal medulla.