L-serine deaminase of Escherichia coli.
The native l-serine deaminase (l-serine hydrolyase, deaminating, EC 4.2.1.13) of Escherichia coli K-12, which seems to be a very labile protein, is rather stable in concentrated solution. Dilution rapidly inactivates it, but in the presence of a saturating concentration of l-serine the molecule is protected from inactivation. It is a very specific enzyme; l-serine is the sole substrate with a K(m) value of 6.60 x 10(-3)m. d-Serine and l-cysteine are competitive inhibitors. Substrate saturation curves of the native enzyme show sigmoid shape, whereas the enzyme liberated from the bacteria in the presence of l-serine exhibits normal Michaelis-Menten kinetics.
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004926:Escherichia coli / Q000201:enzymology*; D006836:Hydro-Lyases; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012694:Serine
D012694:Serine; D006836:Hydro-Lyases