Miyata S, Kihara H K
J Cell Physiol. 1982 Mar;110(3):315-7. doi: 10.1002/jcp.1041100316.
Spleen cells cultured release proteins into the culture medium, some of which shows both binding activity to single stranded DNA (ss-DNA) and inhibitory activity to 3H-thymidine incorporation into cells. The inhibitory protein of DNA synthesis was purified to near homogeneity by ammonium sulfate precipitation, ss-DNA-cellulose affinity chromatography, and gel filtration chromatography. The molecular weight of the major band of this protein, as estimated by sodium dodecyl-sulfate gel electrophoresis, was approximately 14,000. The effect of the protein was compared with various cell lines and primary cell culture, and it was found that the protein strongly inhibited DNA synthesis of HeLa, L, and HEp2 cells, but only inhibited to a minor extent synthesis of Ehrlich cells and primary culture of mouse embryo.
培养的脾细胞会向培养基中释放蛋白质，其中一些蛋白质既显示出对单链DNA（ss-DNA）的结合活性，又对3H-胸腺嘧啶核苷掺入细胞具有抑制活性。通过硫酸铵沉淀、ss-DNA-纤维素亲和层析和凝胶过滤层析，将DNA合成抑制蛋白纯化至接近均一。用十二烷基硫酸钠凝胶电泳估计，该蛋白质主要条带的分子量约为14000。将该蛋白质的作用与各种细胞系和原代细胞培养进行比较，发现该蛋白质强烈抑制HeLa、L和HEp2细胞的DNA合成，但对艾氏腹水癌细胞和小鼠胚胎原代培养的DNA合成仅具有轻微抑制作用。
