Isolation of a mimosine degrading enzyme from leucaena leaf

An enzyme which catalyses the degradation of mimosine to 3‐hydroxy‐4(1H)‐pyridone(DHP) has been isolated from Leucaena leucocephala leaf by extraction with ammonium sulphate, purification on Sephadex G‐25 and fractionation on Sepharose 6B and gel electrophoresis. The enzyme was found to have a molecular weight of 140000, a K m value of 1.64 mM ml −1 and maximum reaction velocity of 0.3 mmol DHP produced ml −1 min −1 . Tyrosine was a competitive inhibitor of the enzyme but DHP did not act as a feedback inhibitor. The enzyme has been termed ‘mimosinase'’.