Role of D-amino acid in adaptation of organisms to environmental change

D-氨基酸在生物体适应环境变化中的作用

基本信息

批准号：
11691187
负责人：
YOSHIMURA Tohru
金额：
$ 4.93万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11691187/
关键词：
D-amino acid alanine racemase D-aminoacid oxidase osmolite ラセマーゼ

项目摘要

After the finding that D-serine serves as an agonist of NMDA receptor of a mammalian brain, role of D-amino acids in eucaryotes has been received an increased attention. The fresh water crayfish has been reported to accumulate total free D-alanine by more than 30-fold in muscle after seawater acclimation. We are interested in the realtionship between D-amino acids and the environmental stress, and studied the enzymes related to the D-amino acid metabolism in eucaryotes. We found the alanine racemase from the hepatopancreas of the black tiger prawn, Penaeus monodon. The prawn enzyme is distinguishable immunochemically from bacterial enzymes and differs from fungal enzymes in the moleular weight and subunit structure. Monovalent anions including chloride are involved in the regulation of the enzyme through stabilization and activation. This is consistent with the hypothesis that D-alanine serves as an osmoregulator in marine and euryhaline animals. We also found that the silkworm has serine racemase which has similar properties to the rat brain serine racemase in pH optimum, substrate specificity, and behaviors upon chromatographies. At the stage of pupation, the contents of D-serine increased concomitantly with the increase in this enzymatic activity. In this work, we also studied the three amino acid racemases of Schizosaccharomyces pombe, Alr1p, Alr2p, and Srf1p. Alr1p is a homologs of bacterial alanine racemase. A1r2p is a fission yeast counterpart to bacterial arginine racemase, and Srf1p resembles a rat serine racemase in low catalytic efficiency. These racemases are probably involved in the detoxification of D-amino acids. In this work, we also performed the screening of new enzymes involved in the D-amino acid metabolism in marine and euryhaline animals in Australia and the United States.

在发现D-丝氨酸是哺乳动物大脑NMDA受体的激动剂之后，D-氨基酸在桉树中的作用受到了越来越多的关注。据报道，淡水小龙虾会在海水适应后的肌肉中积累超过30倍的自由D-丙氨酸。我们对D-氨基酸与环境应激之间的房地产感兴趣，并研究了与桉树中D-氨基酸代谢有关的酶。我们从黑色老虎大虾的佩内纳斯·莫登（Penaeus Monodon）的肝脏中找到了丙氨酸种族酶。虾酶与细菌酶有可区分的免疫化学区分，并且与巨量重量和亚基结构中的真菌酶不同。包括氯化物在内的单价阴离子通过稳定和激活参与酶的调节。这与以下假设是D-丙氨酸在海洋和euryhaline动物中用作osmoregulator。我们还发现，蚕的丝氨酸种族酶在pH值，底物特异性和色谱时的行为方面具有与大鼠脑丝氨酸种族主义酶相似的特性。在化合阶段，D-丝氨酸的含量随着这种酶活性的增加而增加。在这项工作中，我们还研究了schizosacchomyces pombe，alr1p，alr2p和srf1p的三个氨基酸种族酶。 ALR1P是细菌丙氨酸种族酶的同源物。 A1R2P是与细菌精氨酸种族酶的裂变酵母对应物，而SRF1P类似于低催化效率的大鼠丝氨酸种族酶。这些种族酶可能参与D-氨基酸的排毒。在这项工作中，我们还筛选了澳大利亚和美国海洋和euryhaline动物中D-氨基酸代谢涉及的新酶。