d-Alanine: Distribution, origin, physiological relevance, and implications in disease

• Published in: Biochimica et biophysica acta. Proteins and proteomics 2020-11, Vol.1868 (11), p.140482-140482, Article 140482
• Main Authors: Lee, Cindy J., Qiu, Tian A., Sweedler, Jonathan V.
• Format: Article
• Language: English
• Subjects: Alanine - metabolism; Alanine - physiology; Animals; Chiral metabolites; d-alanine; d-amino acids; Diabetes Mellitus - metabolism; Disease; Host-microbe; Humans; Kidney Diseases - metabolism; Liver Cirrhosis - metabolism; Mental Disorders - metabolism; Neoplasms - metabolism; Nervous System Diseases - metabolism; NMDA receptor; Ocular Hypertension - metabolism; Short Bowel Syndrome - metabolism; Smoking - metabolism
• ISSN: 1570-9639; 1878-1454
• DOI: 10.1016/j.bbapap.2020.140482

d-Alanine (d-Ala) is an unusual endogenous amino acid present in invertebrates and vertebrates. Compared to its l-isomer, the characterization of d-Ala is challenging because of the need for chiral resolution and the low amounts of the d-enantiomer present. With recent improvements in measurement capabilities, research on d-Ala, along with other d-amino acids, has been growing, especially as the functional significance of d-Ala in the mammalian nervous and endocrine systems is becoming known. Here we provide an overview of the distribution, origin, function, and disease implications of d-Ala. [Display omitted] •d-alanine is widely distributed in invertebrates and vertebrates.•d-alanine originates from diet, microbiota, and potentially endogenous synthesis.•Acts as a putative signaling molecule in the nervous and endocrine systems.•Physiological relevance in the gut-microbiota-brain axis and in the immune response.•d-alanine levels track various disease states suggesting a potential therapeutic role.