β-Leucine (beta-leucine) is a beta amino acid and positional isomer of L-leucine which is naturally produced in humans via the metabolism of L-leucine by the enzyme leucine 2,3-aminomutase.[1][2][3] In cobalamin (vitamin B12) deficient individuals, plasma concentrations of β-leucine are elevated.[3]
Biosynthesis and metabolism in humans
A small fraction of L-leucine metabolism – less than 5% in all tissues except the testes where it accounts for about 33% – is initially catalyzed by leucine aminomutase, producing β-leucine, which is subsequently metabolized into β-ketoisocaproate (β-KIC), β-ketoisocaproyl-CoA, and then acetyl-CoA by a series of uncharacterized enzymes.[1][2]
References
- ^ a b Kohlmeier M (May 2015). "Leucine". Nutrient Metabolism: Structures, Functions, and Genes (2nd ed.). Academic Press. pp. 385–388. ISBN 978-0-12-387784-0. Archived from the original on 22 March 2018. Retrieved 6 June 2016.
Energy fuel: Eventually, most Leu is broken down, providing about 6.0kcal/g. About 60% of ingested Leu is oxidized within a few hours ... Ketogenesis: A significant proportion (40% of an ingested dose) is converted into acetyl-CoA and thereby contributes to the synthesis of ketones, steroids, fatty acids, and other compounds
Figure 8.57: Metabolism of L-leucine Archived 22 March 2018 at the Wayback Machine - ^ a b "Leucine metabolism". BRENDA. Technische Universität Braunschweig. Archived from the original on 17 August 2016. Retrieved 12 August 2016.
- ^ a b "Human Metabolome Database: Showing metabocard for Beta-Leucine (HMDB0003640)".
