Himanen J P, Taira S, Sarvas M, Saris P, Runeberg-Nyman K
Molecular Biology Unit, National Public Health Institute, Helsinki.
Vaccine. 1990 Dec;8(6):600-4. doi: 10.1016/0264-410x(90)90017-g.
The expression and secretion of pertussis toxin subunits S1 to S5 in Bacillus subtilis by the aid of a bacillary signal sequence has been reported. While secretion of subunit S1 was high, that of others was low. Ways have now been explored to improve the yield, using S4 as an example. The addition of a protease inhibitor was found to increase the amount of S4 in the culture supernatant, but the final amount was still much below that of S1. However, intracellular expression of S4 gave a high yield (500 mg l-1) and the aggregated protein could easily be isolated in a few simple steps.
据报道，借助芽孢杆菌信号序列，百日咳毒素亚基S1至S5在枯草芽孢杆菌中得以表达和分泌。虽然亚基S1的分泌量很高，但其他亚基的分泌量较低。现在已以S4为例探索提高产量的方法。发现添加蛋白酶抑制剂可增加培养上清液中S4的量，但最终量仍远低于S1。然而，S4的细胞内表达产量很高（500 mg l-1），并且聚集蛋白可通过几个简单步骤轻松分离。
