LEUCINE

'Leucine' is an α-amino acid with the chemical formula HO₂CCH(NH₂)CH₂CH(CH₃)₂. Its three letter code is leu, its one letter code is L, and its codons are UUA, UUG, CUU, CUC, CUA, and CUG. It is an essential amino acid, which means that humans cannot synthesise it. With a hydrocarbon side chain, leucine is classified as a hydrophobic amino acid. It is an isomer of isoleucine.

Contents

Biosynthesis

References

External links

Biosynthesis

As an essential amino acid, leucine is not synthesized in animals, hence it must be ingested, usually as a component of proteins. It is synthesized in plants and microorganisms via several steps starting from pyruvic acid. The initial part of the pathway also leads to valine. The intermediate α-ketovalerate is converted to α-isopropylmalate and then β-isopropylmalate, which is dehydrogenated to α-ketoisocaproate, which in the final step undergoes reductive amination. Enzymes involved in a typical biosynthesis include:^[1]
# acetolactate synthase
# acetohydroxy acid isomeroreductase
# dihydroxyacid dehydratase
# α-isopropylmalate synthase
# α-isopropylmalate isomerase
# leucine aminotransferase

References

1. Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. ISBN 1-57259-153-6.

External links

★ Leucine biosynthesis

★ Leucine content in food

★ Computational Chemistry Wiki

★ Leucine prevents muscle loss in rats

★ Leucine helps regulate appetite in rats