D-Amino Acids in the Nervous and Endocrine Systems

Abstract

Amino acids are important components for peptides and proteins and act as signal transmitters. Only L-amino acids have been considered necessary in mammals, including humans. However, diverse D-amino acids, such as D-serine, D-aspartate, D-alanine, and D-cysteine, are found in mammals. Physiological roles of these D-amino acids not only in the nervous system but also in the endocrine system are being gradually revealed. N-Methyl-D-aspartate (NMDA) receptors are associated with learning and memory. D-Serine, D-aspartate, and D-alanine can all bind to NMDA receptors. H2S generated from D-cysteine reduces disulfide bonds in receptors and potentiates their activity. Aberrant receptor activity is related to diseases of the central nervous system (CNS), such as Alzheimer's disease, amyotrophic lateral sclerosis, and schizophrenia. Furthermore, D-amino acids are detected in parts of the endocrine system, such as the pineal gland, hypothalamus, pituitary gland, pancreas, adrenal gland, and testis. D-Aspartate is being investigated for the regulation of hormone release from various endocrine organs. Here we focused on recent findings regarding the synthesis and physiological functions of D-amino acids in the nervous and endocrine systems.

Chiral micellar electrokinetic chromatographic separation for determination ofl- andd-primary amines released from murine islets of Langerhans

“…The reason for using this DAA as an IS was that it had not been reported to be found in other tissues. 34,35 In the 20 mM glucose sample from both islet samples, there was a small peak that migrated at a similar time as the D-Ser standard. Spiking experiments were performed to test the identity of this peak (Fig.…”

Gut microbiota–derived D-serine protects against acute kidney injury

“…gut were the primary microbial products (12) and that they played physiologic roles in the central nervous system (13), heart (14), and skin (15). However, the precise roles of the gut microbiota-associated D-amino acids in kidney diseases have yet to be revealed.…”

Multimodal Role of Amino Acids in Microbial Control and Drug Development

“…It also plays a significant role in determining if a particular amino acid will participate in protein formation or it will serve to regulate other cellular functions. For instance, l-amino acids are proteogenic and will form proteins as well as participate in microbial cell wall formation, whereas d-amino acids are non-proteogenic and regulate different functions such as microbial cell wall formation and dispersal of microbial biofilm [28,29]. The chiral behaviour of amino acids is also responsible for stereoselective catabolism of amino acids i.e., D-amino acids will be catabolised only by d-amino acid oxidase (DAAOs) enzymes and l-amino acids will have their corresponding l-amino acid oxidases (LAAOs) for their catabolism [30].…”