Biological implications of oxidation and unidirectional chiral inversion of D-amino acids.
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.
King's Lab, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China. yxwang@sjtu.edu.cn
Yong-Xiang
YX
Wang
Nian
N
Gong
Yan-Fei
YF
Xin
Bin
B
Hao
Xiang-Jun
XJ
Zhou
Catherine C Y
CC
Pang
D000596:Amino Acids / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism; D003605:D-Amino-Acid Oxidase / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000378:metabolism; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D000596:Amino Acids; D003605:D-Amino-Acid Oxidase