天冬氨酸 N-甲基转移酶催化 N-甲基-d-天冬氨酸（NMDA）的生物合成，NMDA 是 NMDA 受体的一种众所周知的选择性激动剂，在小鼠中。

d-Aspartate N-methyltransferase catalyzes biosynthesis of N-methyl-d-aspartate (NMDA), a well-known selective agonist of the NMDA receptor, in mice.

机构信息

Department of Bioengineering, Nagaoka University of Technology, 1603-1, Kamitomioka-machi, Nagaoka, Niigata 940-2188, Japan; Department of Applied Chemistry and Biochemistry, National Institute of Technology (KOSEN), Fukushima College, 30 Nagao, Kamiarakawa, Taira, Iwaki, Fukushima, 970-8034, Japan.

出版信息

Biochim Biophys Acta Proteins Proteom. 2020 Dec;1868(12):140527. doi: 10.1016/j.bbapap.2020.140527. Epub 2020 Aug 25.

DOI:10.1016/j.bbapap.2020.140527

PMID:32853768

Abstract

N-Methyl-d-aspartate (NMDA), which is a selective agonist for the NMDA receptor, has recently been shown to be present in various biological tissues. In mammals, the activity of d-aspartate N-methyltransferase (DDNMT), which produces NMDA from d-aspartate, has been detected only in homogenates prepared from rat tissues. Moreover, the enzymatic properties of DDNMT have been poorly studied and its molecular entity has not yet been identified. In this report, we show for the first time that the activity of DDNMT is present in mouse tissues and succeed in obtaining a partially purified enzyme preparation from a mouse tissue homogenate with a purification fold of 1900 or more, and have characterized the enzymatic activity of this preparation. The results indicate that DDNMT, which is highly specific for d-aspartate and is S-adenosyl-l-methionine-dependent, is a novel enzyme that clearly differs from the known methylamine-glutamate N-methyltransferase (EC 2.1.1.21) and glycine N-methyltransferase (EC 2.1.1.20).

摘要

N-甲基-D-天冬氨酸（NMDA）是 NMDA 受体的选择性激动剂，最近已被证明存在于各种生物组织中。在哺乳动物中，只有从 D-天冬氨酸产生 NMDA 的 D-天冬氨酸 N-甲基转移酶（DDNMT）的活性在从大鼠组织制备的匀浆中被检测到。此外，DDNMT 的酶学特性研究甚少，其分子实体尚未确定。在本报告中，我们首次表明 DDNMT 的活性存在于小鼠组织中，并成功地从鼠组织匀浆中获得了一种部分纯化的酶制剂，其纯化倍数超过 1900 倍，并对该制剂的酶活性进行了表征。结果表明，DDNMT 对 D-天冬氨酸具有高度特异性，并且依赖于 S-腺苷-L-甲硫氨酸，是一种与已知的甲胺谷氨酸 N-甲基转移酶（EC 2.1.1.21）和甘氨酸 N-甲基转移酶（EC 2.1.1.20）明显不同的新型酶。