Biological implications of oxidation and unidirectional chiral inversion of D-amino acids.
Biological implications of oxidation and unidirectional chiral inversion of D-amino acids.
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DOI：
10.2174/138920012799320392
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发表时间：
2012-02
影响因子：
2.3
通讯作者：
Yongxiang Wang;Nian Gong;Yan-Fei Xin;B. Hao;Xiang-jun Zhou;C. Pang
中科院分区：
文献类型：
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作者：
Yongxiang Wang;Nian Gong;Yan-Fei Xin;B. Hao;Xiang-jun Zhou;C. Pang
最近的进展，手性分离的D-和L-氨基酸的色谱法确定存在的几个游离D-氨基酸在各种哺乳动物，包括人类。许多D-氨基酸类似物如外源性NG-硝基-D-精氨酸（D-NNA）、内源性D-亮氨酸、D-苯丙氨酸和D-甲硫氨酸的单向手性转化已被证明以4- 90%的转化率发生，这可能取决于不同物种的D-氨基酸氧化酶（DAAO）的酶活性。已知DAAO催化中性和碱性D-氨基酸氧化脱氨基成其相应的α-酮酸、过氧化氢和氨，并负责手性转化。本文综述了该领域的最新研究进展：1）体内几种D-氨基酸类似物的氧化和手性转化; 2）DAAO在D-氨基酸类似物的氧化和手性转化中不可或缺但不足的作用，特别是在肾脏和大脑中; 3）负责手性转化第二步的未鉴定转氨酶。综述还讨论了D-氨基酸的氧化和手性转化的生理意义，这仍然是一个有争议的话题。
Recent progress in chiral separation of D- and L-amino acids by chromatography ascertained the presence of several free Damino acids in a variety of mammals including humans. Unidirectional chiral inversion of many D-amino acid analogs such as exogenous NG-nitro-D-arginine (D-NNA), endogenous D-leucine, D-phenylanine and D-methionine have been shown to take place with inversion rates of 4-90%, probably dependent on various species D-amino acid oxidase (DAAO) enzymatic activities. DAAO is known to catalyze the oxidative deamination of neutral and basic D-amino acids to their corresponding α-keto acids, hydrogen peroxide and ammonia, and is responsible for the chiral inversion. This review provides an overview of recent research in this area: 1) oxidation and chiral inversion of several D-amino acid analogs in the body; 2) the indispensable but insufficient role of DAAO particularly in the kidneys and brain for the oxidation and chiral inversion of D-amino acids analogs; and 3) unidentified transaminase(s) responsible for the second step of chiral inversion. The review also discusses the physiological significance of oxidation and chiral inversion of D-amino acids, which is still a subject of dispute.