Jones B N, Shively J E, Kilpatrick D L, Stern A S, Lewis R V, Kojima K, Udenfriend S
Proc Natl Acad Sci U S A. 1982 Mar;79(6):2096-100. doi: 10.1073/pnas.79.6.2096.
[Met]Enkephalin-containing proteins of 8600 and 12,600 daltons have been isolated from acid extracts of bovine adrenal medulla and purified to homogeneity, and their sequences have been determined by a combination of automated Edman degradation, tryptic mapping, and enzymatic time-course hydrolysis. The 8600-dalton protein contains one copy of the [Met]enkephalin sequence at the COOH terminus and the 12,600-dalton protein contains three copies of [Met]enkephalin, of which two are internal and the third is at the COOH terminus. They possess identical NH2-terminal amino acid sequences, suggesting that the 8600-dalton protein is derived from the 12,600-dalton protein by intracellular proteolytic processing. This is supported by results from tryptic maps of both proteins. Furthermore, chemical analysis of the tryptic peptides obtained from the 12,600-dalton protein indicates that it also contains the amino acid sequence that corresponds to a previously characterized enkephalin-containing polypeptide of 3800 daltons (peptide F) [Jones et al. (1980) Arch. Biochem. Biophys. 204, 392-395]. All three polypeptides appear to be intermediates in posttranslational processing of a still larger polyenkephalin precursor molecule, proenkephalin, and part of a biosynthetic pathway leading to smaller enkephalin-containing polypeptides and free enkephalins.
已从牛肾上腺髓质的酸提取物中分离出分子量为8600和12,600道尔顿的含[甲硫氨酸]脑啡肽蛋白,并将其纯化至同质,其序列已通过自动Edman降解、胰蛋白酶图谱分析和酶促时间进程水解相结合的方法确定。8600道尔顿的蛋白在COOH末端含有一个[甲硫氨酸]脑啡肽序列拷贝,12,600道尔顿的蛋白含有三个[甲硫氨酸]脑啡肽拷贝,其中两个在内部,第三个在COOH末端。它们具有相同的NH2末端氨基酸序列,表明8600道尔顿的蛋白是通过细胞内蛋白水解加工从12,600道尔顿的蛋白衍生而来。两种蛋白的胰蛋白酶图谱结果支持了这一点。此外,对从12,600道尔顿的蛋白获得的胰蛋白酶肽段的化学分析表明,它还包含与先前鉴定的3800道尔顿含脑啡肽多肽(肽F)相对应的氨基酸序列[琼斯等人(1980年)《生物化学与生物物理学档案》204, 392 - 395]。所有这三种多肽似乎都是一个更大的多脑啡肽前体分子——前脑啡肽在翻译后加工过程中的中间体,并且是导致更小的含脑啡肽多肽和游离脑啡肽的生物合成途径的一部分。