模拟酶研究进展

综述了近年来模拟酶的研究及进展,着重介绍了配合物模拟水解酶、超氧化物模拟歧化酶的进展及其他模拟酶的合成研究进展。

天源(生化)有机液肥在蔬菜上的应用

当前,农业施肥正朝着施用无毒、无害的微生物有机肥的方向发展。根据有关资料介绍,天源(生化)有机液肥是无毒、无害、无污染、安全高效的有机肥。该肥是利用水产品有机质等主要原料,经过特殊微生物发酵,以生化程序处理生产的。其成份除了氮、磷、钾及微量元素外,并含有20余种植物所不可少的氨基酸、维生素等。它不仅有利作物内部酶的合成并增加活性,提高光合作用的效率。

老人也需微量元素

老人也需微量元素文王有国近年发现多种微量元素有抗衰老功能，因此，与儿童发育离不开微量元素一样，老年人也需要补克必需的微量元素。１锌人体内的锌参与多种酶的合成，与８０多种酶的活牲有关，缺锌时会降低含锌酶的活性。酶就是人体内的生物催化剂，它的活性高低，就...

冬季宝宝营养餐谱

特别提示:冬季要预防锌缺乏症。锌有多种生物作用,参与多种酶的合成。锌可促进生长发育和智力发展,平时应重视给孩子多吃含锌高的辅食,如牡蛎、牛肉、虾、牛[羊]肝、蛋黄、鱼类及豆制品。

Enzymatic synthesis of nucleosides by nucleoside phosphorylase co-expressed in Escherichia coli

Nucleoside phosphorylase is an important enzyme involved in the biosynthesis of nucleosides. In this study, purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase were co-expressed in Escherichia coli and the intact cells were used as a catalyst for the biosynthesis of nucleosides. For protein induction, lactose was used in place of isopropyl β-D-l-thiogalactopyranoside （IPTG）. When the concentration of lactose was above 0.5 mmol/L, the ability to induce protein expression was similar to that of IPTG. We determined that the reaction conditions of four bacterial strains co-expressing these genes （TUD, TAD, DUD, and DAD） were similar for the biosyntheses of 2,6-diaminopurine nucleoside and 2,6-diaminopurine deoxynucleoside. When the substrate concentration was 30 mmol/L and 0.5% of the recombinant bacterial cell volume was used as the catalyst （pH 7.5）, a greater than 90% conversion yield was reached after a 2-h incubation at 50℃. In addition, several other nucleosides and nucleoside derivatives were efficiently synthesized using bacterial strains co-expressing these recombinant enzymes.