Kita K, Omata S, Horigome T
Department of Biochemistry, Faculty of Science, Niigata University.
J Biochem. 1993 Mar;113(3):377-82. doi: 10.1093/oxfordjournals.jbchem.a124054.
It is known that nucleoporins, a family of glycoproteins with N-acetylglucosamine that are found in nuclear pore complexes, are essential for nuclear import and export. A major component of the family, p62, was purified from a salt extract of rat liver nuclear envelopes by wheat germ agglutinin-Sepharose affinity chromatography and DEAE-anion exchange HPLC. p62 was purified as a complex with two glycoproteins of 60 and 54 kDa. The presence of the complex was confirmed by gel filtration, glycerol density gradient centrifugation, and cross-linking experiments. The molecular ratio of the 62-, 60-, and 54-kDa components of the complex was estimated to be 1: 1.1 +/- 0.2: 1.7 +/- 0.3 from the intensity of Coomassie Blue staining of SDS-PAGE gels. The complex was stable against 1 M NaCl, 1% Triton X-100, and 2 M urea. The Stokes' radius and sedimentation coefficient of the complex are 8.0 nm and 6.7 S. The molecular mass and frictional ratio of the complex were estimated to be about 231 kDa and 2.0, respectively. p62 and p54 were acidic and neutral proteins, respectively, exhibiting charge heterogeneities, and p60 was assumed to be a basic protein. p60 tended to undergo proteolytic degradation to a 47-kDa fragment.
已知核孔蛋白是一类存在于核孔复合体中的带有N-乙酰葡糖胺的糖蛋白，对核输入和输出至关重要。该家族的一个主要成分p62，通过麦胚凝集素-琼脂糖亲和层析和DEAE-阴离子交换高效液相色谱从大鼠肝核膜的盐提取物中纯化得到。p62作为一种与60 kDa和54 kDa的两种糖蛋白的复合物被纯化出来。通过凝胶过滤、甘油密度梯度离心和交联实验证实了该复合物的存在。根据SDS-PAGE凝胶考马斯亮蓝染色的强度，估计该复合物中62 kDa、60 kDa和54 kDa成分的分子比例为1:1.1±0.2:1.7±0.3。该复合物对1 M NaCl、1% Triton X-100和2 M尿素具有稳定性。该复合物的斯托克斯半径和沉降系数分别为8.0 nm和6.7 S。该复合物的分子量和摩擦比估计分别约为231 kDa和2.0。p62和p54分别为酸性和中性蛋白，表现出电荷异质性，p60被认为是一种碱性蛋白。p60倾向于被蛋白水解降解为一个47 kDa的片段。
