Kinetic properties of chicken carnosine N-methyltransferase.

Kinetic properties were determined with the use of homogenous recombinant chicken HNMT-like protein and chicken muscle carnosine N-methyltransferase purified by chromatography on DEAE-Sepharose, Q-Sepharose, Superdex 200 and Superdex 75.Determinations for S-adenosyl-L-methionine (SAM) were performed with enzyme preparations that were incubated for 10–15 min in the presence of 20 mM carnosine and variable concentrations of (1H+3H)SAM, while the measurements for carnosine were done in the presence of non-saturating 1 µM concentration of (1H+3H)SAM. Values are the means of three separate experiments. The S.E. value is also given.