Kinetic Characterization of a Short N‐acetyl Glutamate Synthase from Alicyclobacillus acidocaldarius

N-acetyl glutamate synthase (NAGS) is the first enzyme in arginine biosynthetic pathway and catalyzes transfer of an acetyl group from acetyl-CoA to L-glutamate produce N-acetylglutamate (NAG). NAGS enzymes either consist two domains (classical NAGS) or a single domain (short S-NAGS). S-NAGS, although present many bacteria, have not been well characterized date. This study's focus kinetically characterize putative S-NAGS Alicyclobacillus acidocaldarius. Initial kinetics demonstrated low activity with L-glutamine (Km = 135 mM, kcat 0.0631 s-1, kcat/Km 0.4674 M-1s-1) too large determine, 1.7x10-4 as substrates which consistent only other characterization S-NAGS. Surprisingly, inhibited by L-arginine like instead uses substrate significantly greater efficiency than any amino acid 21 0.0192 0.9143 M-1s-1). Preliminary studies indicate that follows sequential kinetic mechanism.