Vanderpuye O A, Smith C H
Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St Louis Children's Hospital, Missouri 63178.
Placenta. 1987 Nov-Dec;8(6):591-608. doi: 10.1016/0143-4004(87)90030-0.
Proteins of the basal and microvillous plasma membranes of the human placental syncytiotrophoblast were compared to elucidate the basis for structural and functional differences in the two membranes. Among the proteins common to both membranes were actin, alkaline phosphatase, albumin, transferrin, immunoglobulin G, proteins of Mr 35,000, 55,000 and 180,000, and five immunochemically detected proteins. Each membrane also contained unique proteins. Major microvillous cytoskeleton proteins of Mr 68,000 80,000 and 105,000 (alpha-actinin) were lacking or absent from basal membrane cytoskeletons which instead contained unique proteins of Mr 14,000, 16,000, 220,000 and 240,000. In addition, immunochemical analyses revealed four glycoprotein antigens unique to microvillous membrane and five unique to basal membrane. Fibronectin was also found to be exclusive to basal membrane. The difference in membrane-associated cytoskeletal proteins correlated with the different organization of actin microfilaments at the two membranes. The protein antigens unique to each of the two membranes provided further evidence for the polarization of membrane proteins and functions in the syncytium.
对人胎盘合体滋养层基底质膜和微绒毛质膜的蛋白质进行了比较，以阐明这两种膜在结构和功能上差异的基础。两种膜共有的蛋白质包括肌动蛋白、碱性磷酸酶、白蛋白、转铁蛋白、免疫球蛋白G、分子量为35000、55000和180000的蛋白质，以及五种通过免疫化学检测到的蛋白质。每种膜还含有独特的蛋白质。基底膜细胞骨架中缺乏分子量为68000、80000和105000（α-辅肌动蛋白）的主要微绒毛细胞骨架蛋白，取而代之的是含有分子量为14000、16000、220000和240000的独特蛋白质。此外，免疫化学分析显示微绒毛膜有四种独特的糖蛋白抗原，基底膜有五种独特的糖蛋白抗原。还发现纤连蛋白仅存在于基底膜中。与膜相关的细胞骨架蛋白的差异与两种膜上肌动蛋白微丝的不同组织方式相关。两种膜各自独特的蛋白质抗原为合体中膜蛋白和功能的极化提供了进一步的证据。
