Function and regulation of D-amino acid biosystem in eukaryote

在这些研究中，我们研究了锌在酿酒酵母D-丝氨酸脱水酶中的作用。我们还研究了粘质纤维霉菌盘状网柄菌丝氨酸外消旋酶的反应机理，发现该酶与Lys56和Ser81的反应是通过两个碱基进行的。为了阐明D-天冬氨酸在哺乳动物中的作用，我们克隆了小鼠GOT1L1的基因，该基因被认为是一种天冬氨酸氨基转移酶，并试图纯化该蛋白。我们还研究了D-丝氨酸的代谢，以了解D-丝氨酸在发育中的作用。我们构建了缺乏D-丝氨酸脱水酶的突变的盘孢子虫细胞，D-丝氨酸脱水酶负责丝氨酸的降解。突变细胞在多细胞期含有D-丝氨酸，子实体形成存在缺陷。我们还构建了聚乙二醇化的D-丝氨酸脱水酶，可以作为体内降解D-丝氨酸的工具。修饰后的酶免疫原性降低。

In these studies, we examined the role of zinc in the D-serine dehydratase of Saccharomycescerevisiae. We also studied the reaction mechanism of serine racemase of a slime cellularmold, Dictyostelium discoidium, and found that the enzyme reaction proceeds through thetwo-base mechanism with Lys56 and Ser81. In order to clarify the role of D-aspartatein mammals, we cloned the gene of mouse GOT1L1, which was suggested to be an asparateracemase, and attempted to purify the protein. We also studied the D-serine metabolismin D. discoidium to understand the role of D-serine in development. We constructed themutant D. discoidium cells lacking D-serine dehydratase, which is responsible for theD-serine degradation. The mutant cells contained D-serine at their multicellular stageand showed the defects in fruiting body formation. We also constructed the polyethyleneglycol-modified D-serine dehydratase, which can be a tool for the in vivo D-serinedegradation. The modified enzyme exhibited a decreased immunogenicity.