Yamashita K, Matsuda K, Hayashi H, Hanaoka Y, Tanaka S, Yamamoto K, Kikuyama S
Department of Biology, School of Education, Waseda University, Tokyo, Japan.
Gen Comp Endocrinol. 1993 Sep;91(3):307-17. doi: 10.1006/gcen.1993.1131.
Two forms of highly purified prolactin (PRL) were obtained from pituitary glands of Xenopus laevis by extraction of acetone-dried powder with acid acetone and high-performance liquid chromatography on anion exchange, gel filtration, and reverse-phase columns. Purification was monitored by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis employing antiserum against bullfrog PRL. The Xenopus prolactins (xPRL-I and xPRL-II) thus obtained were shown to have similar molecular weights of 23,000 as determined by SDS-PAGE. The isoelectric points of xPRL-I and xPRL-II determined by isoelectric focusing were 5.6 and 5.3, respectively. Both hormones blocked T4-induced shrinkage of Xenopus tadpole tail fin in vitro. The amino acid compositions of the xPRLs resembled that of bullfrog PRL. The partial amino acid sequences of xPRL-I and of xPRL-II showed 78 and 68% homology with the comparable portion of the sequence of bullfrog PRL, respectively. Homology between xPRL-I and xPRL-II was 90%.
通过用酸性丙酮提取丙酮干燥粉末，并在阴离子交换柱、凝胶过滤柱和反相柱上进行高效液相色谱，从非洲爪蟾的垂体中获得了两种高度纯化的催乳素（PRL）。通过SDS-聚丙烯酰胺凝胶电泳（SDS-PAGE）和使用抗牛蛙PRL抗血清的蛋白质免疫印迹分析来监测纯化过程。由此获得的非洲爪蟾催乳素（xPRL-I和xPRL-II）经SDS-PAGE测定显示分子量相似，均为23,000。通过等电聚焦测定，xPRL-I和xPRL-II的等电点分别为5.6和5.3。两种激素在体外均能阻断T4诱导的非洲爪蟾蝌蚪尾鳍收缩。xPRL的氨基酸组成与牛蛙PRL的相似。xPRL-I和xPRL-II的部分氨基酸序列分别与牛蛙PRL序列的相应部分显示出78%和68%的同源性。xPRL-I和xPRL-II之间的同源性为90%。
