Physiolozical role and biosynthesis of D-aminoacids in eukanyote

D-氨基酸在真核生物中的生理作用和生物合成

基本信息

批准号：
10680607
负责人：
YOSHIMURA Tohru
金额：
$ 1.92万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10680607/
关键词：
D-aminoacid D-serine D-alanine racemase 分裂酵母カイコ真核細胞

项目摘要

D-Amino acids are indispensable for eubacteria as components of the peptidoglycans of their cell walls. Although several D-amino acids were found as components of opioid-like peptides and antibiotics such as cyclosporin A, little attention has been paid to the physiological function of D-amino acid in eukaryotes.However, recent advances in analytical techniques have enabled the demonstration of D-amino acid in various animals including mammals. In this work, we have studied the enzymes which are involved in the D-amino acid biosynthesis in eukaryote. We found that pyridoxal phosphate-dependent serine racemase occurs in the insect. The enzyme was partially purified from pupae of silkworm, Bombyx mori, and its properties were studied. This is the first report of the occurrence of serine racemase in eukaryotes producing D-serine. We partially purified and characterizde the alanine racemase from the hepatopancreas of the black tiger prawn, Penaeus monodon. The enzyme was immunochemically distinguished from alanine racemase from bacteria. We found that monovalent anions are involved in the regulation of the black tiger enzyme. It is compatible with the speculation that D-alanine is involved in the osmotic stress response in several marine and euryhaline invertebrates[9-14]. We also studied the reaction mechanism of alanine racemase from thermophilic bacteria, Bacillus stearothermophilus.

D-氨基酸作为真细菌细胞壁肽聚糖的组成部分是不可或缺的。尽管多种 D-氨基酸被发现是阿片样肽和环孢菌素 A 等抗生素的成分，但人们对 D-氨基酸在真核生物中的生理功能却很少关注。然而，分析技术的最新进展已经能够证明D-氨基酸在包括哺乳动物在内的各种动物中的含量。在这项工作中，我们研究了真核生物中参与 D-氨基酸生物合成的酶。我们发现昆虫体内存在磷酸吡哆醛依赖性丝氨酸消旋酶。该酶从家蚕（Bombyx mori）蛹中部分纯化，并研究了其性质。这是在产生D-丝氨酸的真核生物中出现丝氨酸消旋酶的首次报道。我们从黑虎虾斑节对虾的肝胰腺中部分纯化并表征了丙氨酸消旋酶。该酶通过免疫化学方法与细菌的丙氨酸消旋酶区分开来。我们发现单价阴离子参与黑虎酶的调节。这与 D-丙氨酸参与几种海洋和广盐无脊椎动物的渗透应激反应的推测是一致的[9-14]。我们还研究了嗜热细菌嗜热脂肪芽孢杆菌的丙氨酸消旋酶的反应机制。