Doneen B A, Bern H A, Haoli C
J Endocrinol. 1977 May;73(2):377-83. doi: 10.1677/joe.0.0730377.
These studies are concerned with the structural and functional evolution of the ancestrally related pituitary prolactins and somatotrophins. Prolactin-like biological activities of human somatotrophin (hGH) and its peptide fragments were bioassayed in vitro on the mouse mammary gland and the teleost urinary bladder. Plasmin modified-hGH was as active as hGH in both bioassays. The NH2-terminal 134-residue fragment possessed about 10% of the lactogenic and urinary bladder potency of hGH, whereas the CO2H-terminal 51-residue fragment was inactive at the concentrations observed. These results suggest that the same regions of primary structure are responsible for the prolactin-like actions of hGH on the target organs of lower and higher vertebrates. Alteration of the tertiary structure of hGH, human chorionic somatomammotrophin, and ovine prolactin by performic acid oxidation destroys the mammary gland activities of these hormones.
这些研究关注的是具有共同祖先的垂体催乳素和生长激素的结构与功能演变。人生长激素（hGH）及其肽片段的催乳素样生物活性在体外通过小鼠乳腺和硬骨鱼膀胱进行生物测定。在两种生物测定中，纤溶酶修饰的hGH与hGH活性相当。氨基末端134个残基的片段具有hGH约10%的催乳和膀胱刺激活性，而羧基末端51个残基的片段在观察到的浓度下无活性。这些结果表明，一级结构的相同区域负责hGH对低等和高等脊椎动物靶器官的催乳素样作用。过甲酸氧化改变hGH、人绒毛膜生长催乳素和绵羊催乳素的三级结构会破坏这些激素的乳腺活性。
