一种19kD/pI 4.5核仁磷蛋白的纯化及部分特性分析

Purification and partial characterization of a 19kD/pI 4.5 nucleolar phosphoprotein.

作者信息

McRorie D K, Rao M R, Goldknopf I L, Harty T P, Roll D, Ahn Y S, Busch H

出版信息

Biochem Biophys Res Commun. 1984 Jul 18;122(1):47-55. doi: 10.1016/0006-291x(84)90437-6.

Abstract

Two-dimensional PAGE analysis of proteins associated with the slowly sedimenting "fibrillar" structures of HeLa nucleoli revealed a protein with a M of 19,000 and a pI of 4.5 which was highly labeled both with 32P-orthophosphate and 35S-methionine. The protein was isolated from Novikoff hepatoma nucleoli by extraction in 0.35 M NaCl and 5 mM DTT followed by chromatography in EDTA on DEAE-cellulose and Sephadex G-100. The protein was homogeneous with respect to two-dimensional PAGE, number of tryptic peptides and carboxyl terminal analysis. The protein contained an acidic/basic amino acid ratio of 2.1, 7 residues of methionine, 2 residues of cysteine, a blocked amino terminus and a carboxyl terminal lysylleucine.

摘要

对与HeLa细胞核仁缓慢沉降的“纤维状”结构相关的蛋白质进行二维聚丙烯酰胺凝胶电泳分析，发现一种分子量为19,000、等电点为4.5的蛋白质，该蛋白质用32P-正磷酸盐和35S-甲硫氨酸进行高度标记。通过在0.35M NaCl和5mM二硫苏糖醇中提取，随后在EDTA存在下于DEAE-纤维素和葡聚糖G-100上进行色谱分离，从诺维科夫肝癌细胞核仁中分离出该蛋白质。就二维聚丙烯酰胺凝胶电泳、胰蛋白酶肽数量和羧基末端分析而言，该蛋白质是均一的。该蛋白质的酸性/碱性氨基酸比率为2.1，含有7个甲硫氨酸残基、2个半胱氨酸残基、一个封闭的氨基末端和一个羧基末端赖氨酰亮氨酸。