Simultaneous Measurement of Amino Acid Enantiomers in Aged Mouse Brain Samples by LC/MS/MS Combined with Derivatization Using Nα-(5-Fluoro-2,4-dinitrophenyl)-l-leucinamide (l-FDLA)

Abstract

d-amino acids have distinct roles from their l-enantiomer. In particular, some d-amino acids function as agonists or antagonists of neuronal receptors and are involved in higher brain functions. Thus, it is important to precisely measure the levels of these amino acid enantiomers in cells and tissues. Various quantification methods have been developed for measurements of chiral amino acids. However, each method has advantages and disadvantages. Additionally, measuring the amino acid enantiomers in crude biological samples requires a higher selectivity. In this study, we developed a quantification method for amino acid enantiomers using derivatization with Nα-(5-Fluoro-2,4-dinitrophenyl)-l-leucinamide (l-FDLA) followed by liquid chromatography–tandem mass spectrometry (LC/MS/MS) with a conventional reversed-phase column. We simultaneously identified 10 chiral amino acids. Furthermore, we applied this method to investigate murine tissue samples and examined the effect of aging on the amino acid levels in aged brain regions. We found that aging decreased the levels of both d-serine and d-aspartate in the hippocampus. In addition, d-Phenylalanine in the thalamus significantly increased with age. In conclusion, our method is suitable for the quantification of the d-amino acids in crude biological samples and may contribute to elucidating the biological roles of chiral amino acids.

Oral Administration of Nicotinamide Mononucleotide Is Safe and Efficiently Increases Blood Nicotinamide Adenine Dinucleotide Levels in Healthy Subjects

“…Amino acid metabolomics was performed as described previously ( 44 ). After the extraction of metabolites, the samples were derivatized by incubating with N α-(5-Fluoro-2,4-dinitrophenyl)- L -leucinamide (FDLA).…”

Arrow of Time, Entropy, and Protein Folding: Holistic View on Biochirality

“…It is not trivial that there is less information content in DNA than in the proteins assembled based on genetic code [ 34 ]. Due to advances in the appreciation of biochirality, the intuitive perception of the link between bio-molecular chirality and brain laterality and asymmetry of cognitive function is gradually replaced by a system of experimental facts [ 35 , 36 , 37 , 38 , 39 ]. The evolution of biological symmetry is evident in the animal proteome, cell signaling, and body/brain morphology, originating, mainly, due to the changes in the gene regulatory networks (GRNs) [ 39 , 40 , 41 ].…”

“…Due to advances in the appreciation of biochirality, the intuitive perception of the link between bio-molecular chirality and brain laterality and asymmetry of cognitive function is gradually replaced by a system of experimental facts [ 35 , 36 , 37 , 38 , 39 ]. The evolution of biological symmetry is evident in the animal proteome, cell signaling, and body/brain morphology, originating, mainly, due to the changes in the gene regulatory networks (GRNs) [ 39 , 40 , 41 ]. The human genome contains ∼25,000 protein-coding genes, which are differentially expressed, in response to the various intracellular and extracellular cues.…”

Separation and determination of 3‐hydroxyaspartate by online concentration capillary electrophoresis/laser‐induced fluorescence with microwave‐assisted derivatization

“…The sensitive detection of biologically active enantiomers can provide important information for the deep understanding of their functions in biological systems [1–4]. 3‐Hydroxyaspartate (HA) is a nonprotein amino acid with two chiral centers.…”

“…The sensitive detection of biologically active enantiomers can provide important information for the deep understanding of their functions in biological systems [1][2][3][4].…”