Biosynthesis of selenosubtilisin: A novel way to target selenium into the active site of subtilisin

Glutathione peroxidase （GPx, EC1.11.1.9）, an important anti-oxidative selenoenzyme, can catalyze the reduction of harmful hydroperoxides with concomitant glutathione, thereby protecting cells and other biological issues against oxidative damage. It captures considerable interest in redesign of its function for either the mechanism study or the pharmacological development as an antioxidant. In order to develop a general strategy for specifically targeting and operating selenium in active sites of enzymes, the catalytically essential residue selenocysteine （Sec） was first successfully bioincorporated into the catalytic center of subtilisin by using an auxotrophic expression system. The studies of the catalytic activity and the steady-state kinetics demonstrated that selenosubtilisin is an excellent GPx-like biocatalyst. In comparison with the chemically modified method, biosynthesis exhibits obvious advantages： Sec could be site-directly incorporated into active sites of enzymes to overcome the non-specificity generated by chemical modification. This study provides an important strategy for specifically targeting and operating selenium in the active site of an enzyme.     

硒与免疫功能——硒对大吞噬细胞吞噬活性影响的研究

本研究探讨了硒和V_E对家禽外周血中大吞噬细胞的吞噬活性的影响,结果表明,吞噬细胞的吞噬活性与补硒和V_E有关.补硒和补硒+V_E的鸡,吞噬细胞的吞噬活性都明显的高于试验前及对照组,且硒和V_E对吞噬活性的增强有一定的协同作用.     

取代冠醚及其缩氨硫脲和缩氨脲化合物的合成

本文报道采用在多聚磷酸中将冠醚酰化的方法，合成了４＇－苯甲酰基苯并－１５－冠－５，以此为原料，在酸性条件下，与氨基硫脲和氨基脲反应，合成了４＇－苯甲酰缩氨基硫脲和缩氢基脲苯并－１５－冠－５，并对合成的三种新物质由ＩＲ、ＭＳ、和元素分析鉴定了结构。     

化合物半导体CdSe和ZnSe材料的状态密度

本文用Ｔ．Ｂ．－Ｒｏｃｕｒｓｉｏｎ方法计算了化合物半导体ＣｄＳｅ和ＺｎＳｅ的状态密度曲线，求出了费米能级和带隙，与实验结果符合得很好。