Landau T, Sachs L
Proc Natl Acad Sci U S A. 1971 Oct;68(10):2540-4. doi: 10.1073/pnas.68.10.2540.
A substance produced by various types of cells can induce from single hematopoietic cells the formation of colonies of normal macrophages and granulocytes. This inducer has been purified 600-fold from serum-free conditioned medium from a tissue culture line of mouse cells. It is shown that the inducer is a protein, with a molecular weight of 65-70,000, whose inducing activity was about 1 ng per colony. Acrylamide gel electrophoresis of this material gave four bands, only one of which contained inducing activity. The purified protein was inactive. Activity was regained by the addition of a low molecular weight cofactor that is present in conditioned medium. Under certain conditions, activity was also regained by the addition of adenosine 3':5'-cyclic monophosphate (cyclic AMP).
多种类型细胞产生的一种物质能够从单个造血细胞诱导形成正常巨噬细胞和粒细胞集落。这种诱导剂已从小鼠细胞组织培养系的无血清条件培养基中纯化了600倍。结果表明,该诱导剂是一种蛋白质,分子量为65000 - 70000,其诱导活性约为每集落1纳克。这种物质的丙烯酰胺凝胶电泳产生了四条带,其中只有一条带具有诱导活性。纯化后的蛋白质没有活性。通过添加条件培养基中存在的低分子量辅因子可恢复活性。在某些条件下,添加3':5'-环磷酸腺苷(环磷酸腺苷)也可恢复活性。