Bunel D T, Conlon J M, Chartrel N, Tonon M C, Vaudry H
European Institute for Peptide Research, CNRS URA 650, UA INSERM, University of Rouen, Mont-Saint-Aignan, France.
Brain Res Mol Brain Res. 1992 Sep;15(1-2):1-7. doi: 10.1016/0169-328x(92)90143-y.
Peptides that are derived from the processing of proopiomelanocortin were isolated in pure form from the brain of the frog Rana ridibunda. The primary structure of the most abundant of those peptides was established as: Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val. This amino acid sequence is identical to that of mammalian and frog pituitary alpha-melanocyte-stimulating hormone (MSH) and the peptide co-eluted with synthetic desacetyl alpha-MSH, indicating that it is COOH-terminally alpha-amidated. A second component, which exhibited a shorter retention time, co-eluted with the glycine-extended form of desacetyl alpha-MSH [ACTH(1-14)]. The primary structure of the third peptide isolated in pure form from the brain extract was established as: Lys-Tyr-Val-Met-Ser-His-Phe-Arg-Trp-Asn-Lys-Phe-NH2. This sequence corresponds to Lys-gamma 1-MSH as predicted from the nucleotide sequence of frog proopiomelanocortin. The presence of substantial amounts of desacetyl alpha-MSH and Lys-gamma 1-MSH in the frog brain supports the concept that, in amphibia, melanotropins may act as neurotransmitters and/or neuromodulators as well as hormonal peptides.
从林蛙的大脑中以纯形式分离出了源自阿黑皮素原加工过程的肽。其中最丰富的那种肽的一级结构确定为：Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val。该氨基酸序列与哺乳动物和青蛙垂体的α-黑素细胞刺激素（MSH）相同，且该肽与合成的去乙酰化α-MSH共洗脱，表明其羧基末端是α-酰胺化的。第二个组分保留时间较短，与去乙酰化α-MSH的甘氨酸延伸形式[促肾上腺皮质激素（1-14）]共洗脱。从脑提取物中以纯形式分离出的第三种肽的一级结构确定为：Lys-Tyr-Val-Met-Ser-His-Phe-Arg-Trp-Asn-Lys-Phe-NH2。该序列与从青蛙阿黑皮素原的核苷酸序列预测的Lys-γ1-MSH相对应。青蛙大脑中存在大量的去乙酰化α-MSH和Lys-γ1-MSH，这支持了在两栖动物中，黑素细胞刺激素可能作为神经递质和/或神经调节剂以及激素肽发挥作用的观点。
