【摘要】 采用离子交换层析和Oligo(dT)-纤维素亲和层析相结合的方法,从小牛胸腺分离纯化末端脱氧核苷酰转移酶(TdT),500g胸腺TdT的比活性为1076～2030u/mg蛋白,总活性为4400～7296u,聚丙烯酰胺凝胶电泳一条带,SDS-凝胶电泳测其分子量得到7900和23700道尔顿的两个亚基,不含DNA聚合酶。更多还原

【Abstract】 The calf thymus is an excellent sourcefor enzyme preparation and purification. Inthis study, using a combined method of ex-change columns and Oligo （dT）-celluloseaffinity chromatography, TdT was purifiedand prepared from calf thymus. The proce-dure consisted of: （1） calf thymus tissue washomogenized and allowed to thaw over-night, to precipitate the acidic proteins at pH6.5; （2） followed by the phosphocelluloseabsorption; （3）the DEAE-cellulose chromato-graphy; （4）35-55% （NH₄）₂SO₄ cut; and （5）Oligo（dT）-cellulose affinity chromatography.Thus, it was possible to obtain 7-10 mp TdTfrom 500g of the calf thymus with a totalTdT activity of 4400-7296 units and a specificactivty of 1076-2130 u/mg of protein. Theenzyme exhibited a single zone in 10% poly-acrylamide gel electrophoresis and sodiumdodecyl sulfate （SDS）-polyacrylamide gelelectrophoresis contained two polypeptidewith molecular weight of about 7900 an?23700 respectively, corresponding to the α（10000）and β（23000） subunit of TdT reportedpreviously by Okamura.更多还原