Yasuda A, Yamaguchi K, Papkoff H, Yokoo Y, Kawauchi H
Laboratory of Molecular Endocrinology, School of Fisheries Sciences, Kitasato University, Iwate, Japan.
Gen Comp Endocrinol. 1989 Feb;73(2):242-51. doi: 10.1016/0016-6480(89)90097-x.
The complete amino acid sequence of growth hormone (GH) from a reptilian species (the sea turtle, Chelonia mydas) has been determined for the first time. The hormone was reduced, carboxymethylated, and subsequently cleaved in turn with cyanogen bromide and Staphylococcus aureus protease. The intact protein was also cleaved with lysyl endopeptidase and o-iodosobenzoic acid. The resulting fragments were exclusively separated by reversed-phase high-performance liquid chromatography and subjected to sequence analysis by automated gas-phase sequencer employing the Edman method. The sea turtle GH consist of 190 amino acid residues with two disulfide linkages formed between residues 52-160 and 180-188, and possesses a microheterogeneity, indicated by the presence or absence of an additional alanine residue at the N-terminus. Sequence identities of sea turtle GH to other species of GH are 89% with chicken GH, 79% with rat GH, 68% with blue shark GH, 58% with eel GH, 59% with human GH, and 40% with a teleostean GH such as chum salmon. On the basis of amino acid sequence comparisons, a molecular phylogenetic tree is proposed.
首次测定了一种爬行类动物（绿海龟，蠵龟）生长激素（GH）的完整氨基酸序列。该激素经还原、羧甲基化处理，随后依次用溴化氰和金黄色葡萄球菌蛋白酶进行切割。完整蛋白质还用赖氨酰内肽酶和邻碘苯甲酸进行了切割。所得片段通过反相高效液相色谱法进行分离，并采用埃德曼法通过自动气相测序仪进行序列分析。绿海龟生长激素由190个氨基酸残基组成，在第52 - 160位和180 - 188位残基之间形成两个二硫键，并且具有微异质性，这表现为N端存在或不存在一个额外的丙氨酸残基。绿海龟生长激素与其他物种生长激素的序列同一性分别为：与鸡生长激素89%，与大鼠生长激素79%，与蓝鲨生长激素68%，与鳗鱼生长激素58%，与人类生长激素59%，与诸如秋鲑等硬骨鱼类生长激素40%。基于氨基酸序列比较，构建了一个分子系统发育树。
