Barnes D W, Silnutzer J
J Biol Chem. 1983 Oct 25;258(20):12548-52.
Serum spreading factor (SF) was isolated from human serum by a four-step procedure employing affinity chromatography on glass beads, concanavalin A-Sepharose, DEAE-agarose, and heparin-agarose. The final product was purified approximately 260-fold from the starting material and was maximally active in assays of cell spreading-promoting activity at 300 ng/ml. The isolated human SF preparation consisted of two proteins of apparent molecular weights approximately 65,000 (SF65) and 75,000 (SF75). Both SF65 and SF75 have been shown previously to exhibit cell spreading-promoting activity and to bind monoclonal antibody to human serum SF.
血清扩散因子（SF）通过以下四步程序从人血清中分离出来：在玻璃珠、伴刀豆球蛋白A-琼脂糖、二乙氨基乙基琼脂糖和肝素琼脂糖上进行亲和层析。最终产物从起始材料中纯化了约260倍，在细胞扩散促进活性测定中，300 ng/ml时活性最高。分离出的人SF制剂由两种表观分子量分别约为65,000（SF65）和75,000（SF75）的蛋白质组成。先前已证明SF65和SF75均表现出细胞扩散促进活性，并与人血清SF的单克隆抗体结合。
