Wada M, Kasumimoto T, Miki T, Osada H, Kato S
Genetic Engineering Section, Sagami Chemical Research Center, Kanagawa, Japan.
J Biotechnol. 1990 Mar;13(4):325-34. doi: 10.1016/0168-1656(90)90080-u.
A hybrid protein between staphylococcal protein A and human lymphotoxin, ALT, was produced in Escherichia coli by expression of a recombinant plasmid containing the respective genes. IgG-binding activity of ALT was confirmed by Western blotting analysis and by affinity purification with IgG-Sepharose column chromatography. The purified ALT had cytotoxicity on mouse L-929 cells and its specific activity was approximately 3.5-5.0 X 10(6) U mg-1. ALT was partially degraded by a protease including in the E. coli lysate or trypsin and was converted to lymphotoxin which lacks the NH2-terminal 19 residues but possesses higher cytotoxic activity than ALT.
通过表达含有葡萄球菌蛋白A和人淋巴毒素（ALT）各自基因的重组质粒，在大肠杆菌中产生了一种两者的杂合蛋白。通过蛋白质印迹分析以及用IgG-琼脂糖柱色谱进行亲和纯化，证实了ALT的IgG结合活性。纯化后的ALT对小鼠L-929细胞具有细胞毒性，其比活性约为3.5 - 5.0×10⁶ U mg⁻¹。ALT被大肠杆菌裂解物中包含的一种蛋白酶或胰蛋白酶部分降解，并转化为淋巴毒素，该淋巴毒素缺少NH₂末端的19个残基，但具有比ALT更高的细胞毒性活性。
