Gorovsky M A, Pleger G L, Keevert J B, Johmann C A
J Cell Biol. 1973 Jun;57(3):773-81. doi: 10.1083/jcb.57.3.773.
Histone fraction F2A1 has been isolated and purified from macronuclei of the ciliate Tetrahymena pyriformis. It migrates as a single species on sodium dodecyl sulphate-acrylamide gel electrophoresis, with a molecular weight indistinguishable from that of calf thymus F2A1. The solubility properties of Tetrahymena F2A1 are also similar to those of calf thymus F2A1. Electrophoretic analyses on urea-acrylamide gels indicate that Tetrahymena F2A1 consists of four or five subspecies, the two fastest having electrophoretic mobilities identical with those of the two major electrophoretically separable forms of calf thymus F2A1. High resolution (long gel) electrophoresis coupled with incorporation of radioactive acetate both in vivo and in vitro suggest that, as in the case of calf thymus F2A1, differentical acetylation of a parent molecule can explain the observed electrophoretic heterogeneity of Tetrahymena F2A1. Electrophoretic analysis of histones isolated from the micronucleus, which is genetically less active than the macronucleus, indicates that it contains largely the relatively unacetylated (parent) form of histone F2A1.
组蛋白F2A1已从梨形四膜虫的大核中分离并纯化出来。它在十二烷基硫酸钠-丙烯酰胺凝胶电泳中以单一物种迁移，其分子量与小牛胸腺F2A1的分子量无法区分。四膜虫F2A1的溶解性也与小牛胸腺F2A1的相似。在尿素-丙烯酰胺凝胶上的电泳分析表明，四膜虫F2A1由四个或五个亚种组成，其中两个迁移最快的亚种的电泳迁移率与小牛胸腺F2A1的两种主要电泳可分离形式相同。高分辨率（长凝胶）电泳结合体内和体外放射性乙酸盐的掺入表明，与小牛胸腺F2A1的情况一样，母体分子的差异乙酰化可以解释观察到的四膜虫F2A1的电泳异质性。从遗传活性低于大核的小核中分离的组蛋白的电泳分析表明，它主要含有相对未乙酰化的（母体）组蛋白F2A1形式。
