Harrington W N, Godman G C
Proc Natl Acad Sci U S A. 1980 Jan;77(1):423-7. doi: 10.1073/pnas.77.1.423.
A factor in normal serum that selectively and reversibly inhibits proliferation of cells in culture has been enriched 160-fold from calf serum by sequential ammonium sulfate precipitation, gel filtration, and lectin-affinity chromatography. DNA synthesis of normal (but not transformed) rat hepatocytes, human lymphoblast lines, and mitogen-stimulated murine spleen cells is inhibited by greater than 90%, and Vero, murine myeloma, MELC, and a human colon carcinoma cell line to a lesser extent. Growth of other cell lines tested was not affected. Responsive cells are arrested apparently in G1 by this inhibitor, the effect of which is maximal by 24 hr and is spontaneously reversible thereafter unless it is renewed. The active fraction is a protein that migrates with the alpha 2-globulins; it is not a lipoprotein, and it is of high apparent molecular weight.
一种存在于正常血清中能选择性且可逆地抑制培养细胞增殖的因子,已通过连续硫酸铵沉淀、凝胶过滤和凝集素亲和层析从小牛血清中富集了160倍。正常(而非转化的)大鼠肝细胞、人淋巴母细胞系以及有丝分裂原刺激的小鼠脾细胞的DNA合成被抑制超过90%,而Vero细胞、小鼠骨髓瘤细胞、MELC细胞以及一种人结肠癌细胞系受到的抑制程度较小。所测试的其他细胞系的生长未受影响。这种抑制剂能使反应性细胞明显停滞在G1期,其作用在24小时时达到最大,此后除非更新抑制剂,否则会自发逆转。活性组分是一种与α2球蛋白一起迁移的蛋白质;它不是脂蛋白,且表观分子量较高。