Baer A, Schiebel W
Eur J Biochem. 1978 May;86(1):77-84. doi: 10.1111/j.1432-1033.1978.tb12286.x.
DNA polymerase was purified 1000-fold from the cytoplasm of microplasmodia of the myxomycete Physarum polycephalum. The activity was found in two forms exhibiting molecular weights of 204000 and 116000 respectively. Both forms eluted together from DNA-cellulose and DEAE-Sephadex columns. The Stokes radii were 6.5 and 5.5 nm. The sedimentation coefficients were 7.6 and 5.2 S. The frictional ratios of 1.69 suggest a highly hydrated and/or an asymmetric structure of the molecule. The enzyme-catalyzed reaction was sensitive to N-ethylmaleimide (60% inhibition by 1 mM). Unlike DNA polymerase alpha from mammalian cells the Physarum enzyme was stimulated by 30 mM NaCl. Activated DNA was the preferred template. Poly(A) . (DT)12 was not accepted. The Km value for deoxynucleoside triphosphates was 3 micron, for activated DNA 50 microgram/ml and for Mg2+ at the optimum [k+] of 150 mM about 0.6 mM.
从黏菌多头绒泡菌的微原质团细胞质中纯化出了1000倍的DNA聚合酶。该活性以两种形式存在，分子量分别为204000和116000。两种形式从DNA - 纤维素柱和DEAE - 葡聚糖柱上一起洗脱下来。斯托克斯半径分别为6.5和5.5纳米。沉降系数分别为7.6和5.2 S。摩擦比为1.69，表明该分子具有高度水合和/或不对称结构。该酶催化的反应对N - 乙基马来酰亚胺敏感（1 mM时抑制60%）。与哺乳动物细胞的DNA聚合酶α不同，多头绒泡菌的这种酶受到30 mM NaCl的刺激。活化的DNA是首选模板。聚（A）·（DT）12不被接受。脱氧核苷三磷酸的Km值为3微摩尔，活化DNA为50微克/毫升，在最佳钾离子浓度150 mM时，镁离子的Km值约为0.6 mM。
