核抗原：通过分析性和制备性等电聚焦对酸性核核糖核蛋白-Sm抗原复合物的特性研究

Nuclear antigens: characterization of the acidic nuclear ribonucleoprotein-Sm-antigen complex by analytical and preparative isoelectric focusing.

作者信息

Waelti E R, Hess M W

出版信息

J Immunol Methods. 1980;32(2):177-84. doi: 10.1016/0022-1759(80)90071-x.

Abstract

The soluble ribonucleoprotein nuclear antigen (RNP), associated with the Sm antigen and present in extracts of rabbit thymus acetone powder, was purified by ion-exchange chromatography. Analytical isoelectric focussing (IEF) showed two bands at pH 5.2 and two bands at pH 5.4. After treatment by RNAse these 4 bands disappeared, and a new band with a pI of 6.1, representing the intact protein moiety, appeared. During preparative IEF in granulated gels the antigenicity of RNP was lost. Only the Sm antigen could be detected by counter-immunoelectrophoresis. Fractions with Sm antigenicity refocussed as two intense bands (pI 6.8 and 7.2) and one or two fainter bands (pI 6.1). On reducing SDS-PAGE the SM antigen revealed two bands of apparent molecular weights of about 110,000 and 28,500, indicating a total molecular weight of 138,500.

摘要

与Sm抗原相关且存在于兔胸腺丙酮粉提取物中的可溶性核糖核蛋白核抗原（RNP），通过离子交换色谱法进行了纯化。分析性等电聚焦（IEF）在pH 5.2处显示两条带，在pH 5.4处显示两条带。经核糖核酸酶处理后，这4条带消失，出现了一条新带，其等电点为6.1，代表完整的蛋白质部分。在颗粒状凝胶中进行制备性IEF时，RNP的抗原性丧失。通过对流免疫电泳只能检测到Sm抗原。具有Sm抗原性的组分重新聚焦为两条浓带（等电点6.8和7.2）和一条或两条较淡的带（等电点6.1）。在还原SDS-PAGE上，SM抗原显示出两条表观分子量约为110,000和28,500的带，表明总分子量为138,500。