Houston B, Goddard C
Agricultural and Food Research Council Institute of Animal Physiology & Genetics Research, Edinburgh Research Station, Roslin, Midlothian.
J Endocrinol. 1988 Jan;116(1):35-41. doi: 10.1677/joe.0.1160035.
Different forms of GH present in freshly prepared homogenates of chicken pituitary were analysed by high-performance gel permeation chromatography and by immunoblotting following sodium dodecylsulphate polyacrylamide gel electrophoresis, nondenaturing polyacrylamide gel electrophoresis and isoelectric focussing. Chicken GH was found to occur mainly in a monomeric form with a relative molecular mass of 23,500 together with small amounts of interchain disulphide-linked oligomers. No evidence was obtained for proteolytically modified forms of GH nor for a form analogous to the 20K variant of human GH. Isoelectric focussing resolved ten distinct charge variants of chicken GH with isoelectric points between 8.45 and 6.0. The predominant charge variant (pI = 7.85) was present in pituitaries of birds of both sexes at all ages examined (3-114 days) whereas the more acidic forms were not apparent until after day 13. These findings indicate that the chicken pituitary contains different forms of GH, some of which may be developmentally regulated.
采用高效凝胶渗透色谱法以及在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、非变性聚丙烯酰胺凝胶电泳和等电聚焦后进行免疫印迹法，分析了新鲜制备的鸡垂体匀浆中存在的不同形式的生长激素（GH）。结果发现，鸡生长激素主要以相对分子质量为23,500的单体形式存在，同时还有少量链间二硫键连接的寡聚体。未获得生长激素经蛋白水解修饰形式的证据，也未发现类似于人类生长激素20K变体的形式。等电聚焦分离出十种不同的鸡生长激素电荷变体，其等电点在8.45至6.0之间。在所有检查的年龄（3至114天）的雌雄鸟类垂体中均存在主要的电荷变体（pI = 7.85），而酸性更强的形式直到第13天后才明显。这些发现表明，鸡垂体含有不同形式的生长激素，其中一些可能受发育调控。
