Studies on the enzymatic production of nucleosides in the activated methyl cycle

活化甲基循环中酶促生产核苷的研究

基本信息

批准号：
62470123
负责人：
YAMADA Hideaki
金额：
$ 4.29万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

We have developed a simple and efficient method for the production of AdoHcy and related nucleosides from L-homocysteine and corresponding nucleosides with A. faecalis cells as catalysts.However, the involvement of an enzyme activity that can catalyze the interconversion of the D- and L-homocysteine isomers in the reaction system with A. faecalis cells seems very promising as a means of solving this problem. Based on this idea, we again screened microorganisms capable of utilizing both the D- and L-homocysteine isomers as substrater. As a result of this screening, Pseudomonas putida IFO 12996 and several other bacterial strains were found to act as catalysts for the conversion of adenosine and D-homocysteine to the L-form of Adohcy. For practical purposes,though, A. faecalis cells were still superior to P. putida cells because they showed high AdoHcy hydrolase activity and low adenosine deaminase activity. Therefore, we used P. putida cells only as a source of the racemase. By mixing adenosine and D,L-homocysteine with a mixture of A. faecalis cells and P. putida cells in potassium phosphate butter, we essentially obtained a 100% yield.In a similar manner, several novel S-nucleosidylhomocysteines could be synthesized efficiently from the corresponding adenosine analogues and L-homocysteine. The K-carrageean entrapped cells of A. faecalis showed high stability on repeated reactions, whereas free cells were inactivated rapidly. These novel S-nucleosidylhomocysteines alsocould be promising for application in the pharmaceutical and chemotherapeutic fields.

我们已经开发了一种简单有效的方法，用于生产L-荷氨基平半胱氨酸和与烟曲霉细胞的相应核苷作为催化剂。基于这个想法，我们再次筛选了能够利用D-和L-联合半胱氨酸异构体作为底层的微生物。由于这种筛选，发现假单胞菌IFO 12996和其他几种细菌菌株被发现充当腺苷和D-二摩其碱转化为ADOHCY L形的催化剂。 For practical purposes,though, A. faecalis cells were still superior to P. putida cells because they showed high AdoHcy hydrolase activity and low adenosine deaminase activity.因此，我们仅将P. p. p. p. p. p. p. p.通过将腺苷和D混合，L-联合细胞素与磷酸钾黄油中的烟曲霉细胞和P. putida细胞的混合物混合在一起，我们基本上获得了100％的产量。以类似的方式，可以从相应的S-核苷甲基荷胺基体系中获得相似的方式，可以从相应的腺苷类化和l-Homysteate中有效地合成。烟曲霉的K-carrageean细胞对重复反应显示出很高的稳定性，而游离细胞迅速失活。这些新型的S-核苷酸粒细胞素ALSOCOC可以有望在药物和化学治疗领域中应用。