Bohn H, Winckler W
Arch Gynakol. 1977 Jan 27;222(1):5-13. doi: 10.1007/BF00670853.
The isolation and characterization of a new tissue protein (PP7) from human placentae is described. The placental protein PP7 is not specific for the placenta; it is found in relative high concentrations in other human tissues as well. Trace amounts of PP7 occur in erythrocytes, too. In sera this protein could not be detected with the gel diffusion test of Ouchterlony nor with the electroimmunoassay technique. PP7 has a molecular weight of around 40,000 daltons and is composed of two identical subunits which are non-covalently linked. In the ultracentrifuge PP7 sediments with 3.5 S. The isoelectric point was found to be 4.9. Electrophoretically the protein migrates in the range between alpha 2 and beta1-globulins. PP7 is a glycoprotein; its carbohydrate content amounts to 5.4% (hexoses 3.0%, Hexosamine 1.2%, Fucose 0.2%, sialic acid 1.0%). The amino acid composition of the protein is reported, too.
本文描述了从人胎盘中分离和鉴定一种新的组织蛋白（PP7）的过程。胎盘蛋白PP7并非胎盘所特有；在其他人体组织中也发现其浓度相对较高。红细胞中也存在痕量的PP7。在血清中，无论是用奥克特洛尼凝胶扩散试验还是用电免疫测定技术，都检测不到这种蛋白。PP7的分子量约为40,000道尔顿，由两个通过非共价键连接的相同亚基组成。在超速离心机中，PP7的沉降系数为3.5S。发现其等电点为4.9。该蛋白在电泳时迁移于α2球蛋白和β1球蛋白之间。PP7是一种糖蛋白；其碳水化合物含量为5.4%（己糖3.0%、氨基己糖1.2%、岩藻糖0.2%、唾液酸1.0%）。文中还报道了该蛋白的氨基酸组成。
