Kinetic and spectroscopic evidence of negative cooperativity in the action of lysine 2,3-aminomutase.

ABSTRACT: Lysine 2,3-aminomutase (LAM) catalyzes the interconversion of L-lysine and L-β-lysine, a component of a number of antibiotics. The reaction requires the cofactors S-adenosyl-L-methionine (SAM), pyridoxal-5'-phosphate (PLP), and a [4Fe-4S] cluster. LAM is a founding member of the radical SAM superfamily of enzymes. LAM is highly specific for L-lysine and will not accept most other amino acids as substrates. L-alanine and L-2-aminobutyrate at 0.2 M react as substrates for LAM at, respectively, 5 × 10(-6) and 8 × 10(-5) times the rate with saturating L-lysine. Saturating ethylamine accelerates the L-alanine reaction 70-fold, and saturating methylamine accelerates the L-2-aminobutyrate reaction 47-fold. The primary amines binding at the active site of LAM with L-alanine or L-2-aminobutyrate si

SUBMITTER: Ruzicka FJ 

PROVIDER: S-EPMC4337230 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature