In enzymology, a leucine 2,3-aminomutase () is an enzyme that catalyzes the chemical reaction
Hence, this enzyme is responsible for the conversion of -leucine to ò-leucine.
This enzyme belongs to the family of isomerases, specifically those intramolecular transferases transferring amino groups. The systematic name of this enzyme class is (2S)-alpha-leucine 2,3-aminomutase. This enzyme participates in valine, leucine and isoleucine degradation. It employs one cofactor, cobamide.