Wilson S, McCarthy R, Clarke F
J Reprod Immunol. 1984 Jul;6(4):253-60. doi: 10.1016/0165-0378(84)90013-5.
Further biochemical characterisations of the 20 kd and 67 kd EPF active polypeptides from pregnant ewes' sera are described. Both polypeptides are shown to possess compact, disulphide linked domains which are almost totally resistant to proteolytic attack without prior reduction. In contrast to previous reports on the influence of ammonium sulphate on the expression of EPF activity, neither the biochemical nor the activity characteristics of either polypeptide is changed by ammonium sulphate fractionation. In addition, direct comparative studies have been performed which clearly distinguish the EPF active polypeptides from the known ovine hormones, prolactin, placental lactogen and growth hormone.
本文描述了对妊娠母羊血清中20kd和67kd胚胎蛋白因子（EPF）活性多肽的进一步生化特性分析。两种多肽均显示具有紧密的、由二硫键连接的结构域，在未预先还原的情况下，几乎完全抵抗蛋白水解攻击。与先前关于硫酸铵对EPF活性表达影响的报道相反，硫酸铵分级分离并未改变任何一种多肽的生化特性或活性特征。此外，还进行了直接对比研究，明确区分了EPF活性多肽与已知的绵羊激素——催乳素、胎盘催乳素和生长激素。
