变形链球菌B13N重组细胞表面蛋白抗原A的纯化与鉴定

Purification and characterization of recombinant cell surface protein antigen A of Streptococcus sobrinus B13N.

Araki T, Hayakawa M, Abiko Y

Department of Biochemistry, Nihon University School of Dentistry, Chiba, Japan.

Int J Biochem. 1991;23(10):1063-7. doi: 10.1016/0020-711x(91)90146-e.

Abstract

It has been reported that immunization of rhesus monkeys with the surface protein antigen I/II from Streptococcus mutans significantly reduced dental caries. 2. The surface protein antigen A (SpaA) from Streptococcus sobrinus is known to correspond antigenically to I/II. MD51 is an Escherichia coli host containing pMD51, a plasmid encoding the SpaA gene from Streptococcus sobrinus B13N. 3. The recombinant SpaA (rSpaA) was purified from cell extracts of Escherichia coli clone MD51. 4. The purified recombinant SpaA was homogeneous with a molecular weight of 210 kDa according to SDS-PAGE and had an isoelectric point of 4.2 based on isoelectric focusing. 5. Amino acid composition of rSpaA showed a relatively high amount of hydrophobic amino acids (39.7%).

摘要

据报道，用变形链球菌表面蛋白抗原I/II对恒河猴进行免疫可显著降低龋齿发生率。2. 已知远缘链球菌的表面蛋白抗原A（SpaA）在抗原性上与I/II相对应。MD51是一种含有pMD51的大肠杆菌宿主，pMD51是一种编码来自远缘链球菌B13N的SpaA基因的质粒。3. 重组SpaA（rSpaA）从大肠杆菌克隆MD51的细胞提取物中纯化得到。4. 根据SDS-PAGE，纯化的重组SpaA分子量为210 kDa，呈均一性，基于等电聚焦其等电点为4.2。5. rSpaA的氨基酸组成显示疏水性氨基酸含量相对较高（39.7%）。