- α-amino acid used in the biosynthesis of proteins.
- contains an α-amino group (which is in the protonated −NH+3 form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO− form under biological conditions), and an isobutyl side chain, classifying it as a nonpolar (at physiological pH) amino acid.
- essential in humans—the body cannot synthesize it and thus must obtain from the diet.
- a major component of the subunits in ferritin, astacin, and other "buffer" proteins.
Effect of leucine on ALS
Amyotroph Lateral Scler Frontotemporal Degener. 2014 Sep;15(5-6):371-5. doi: 10.3109/21678421.2014.920032. Epub 2014 Jun 6. Plasma amino acids patterns and age of onset of amyotrophic lateral sclerosis. Cecchi M1, Messina P, Airoldi L, Pupillo E, Bandettini di Poggio M, Calvo A, Filosto M, Lunetta C, Mandrioli J, Pisa F, Pastorelli R, Beghi E; EURALS Consortium.
The aim of this study was to verify whether abnormalities in plasma amino acid (AA) levels could be biological correlates of the age of onset in amyotrophic lateral sclerosis (ALS). We undertook plasma AA profiling in a large population comprising 117 newly diagnosed ALS patients and 117 matched controls. ALS patients were stratified in early (58 patients aged < 55 years) versus late onset (59 patients aged > 74 years). We applied a rapid and reproducible method for the analysis of AA using amine reactive isotope coded tags in conjunction with liquid chromatography coupled to Multiple Reaction Monitoring-Mass Spectrometry. Results showed that values of only three AA were significantly different in ALS patients and controls. We found lower levels of leucine and higher levels of glutamate and leucine in early-onset ALS compared to their matched controls. In conclusion, different AA patterns related to the ALS age of onset were found, providing insight into possibly aberrant biochemical pathways that might unlock key pathological pathways.