中国生物工程杂志

IFNa-2b is used widely in clinic for the treatment of chronic hepatitis type B and C. IFNa-2b, as a therapeutic protein, is constantly eliminated from circulation within a short time by physiological processes, such as proteolysis in blood. This is often the limiting process affecting the half-life of IFNa-2b. In this study Tyr at position 89 and Glu at position 159 were substituted by His via site-directed mutagenesis in order to gain a interferon mutagenesis with higher efficiency. IFNα-2bHis89/His159 was expressed as inclusion bodies with the yield of more than 40% of total bacterial protein. The putity of IFNα-2bHis89/His159 was higher than 95% after DEAE Sepharose FF and CM Sepharose FF, and the biological activity was more than 2.8×108 IU•mg-1. The half-life of IFNa-2b was 1.72±0.23h and the half-life of IFNα-2bHis89/His159 was 2.34±0.23h, which was improved slightly in rats.