KINETICS OF THE FORMATION AND HYDROLYSIS OF THE SCHIFF-BASES OF PYRIDOXAL 5'-PHOSPHATE AND COPOLYPEPTIDES CONTAINING L-LYSINE AND AROMATIC L-AMINO-ACIDS

We determined the apparent rate constants of formation (k(1)) and hydr olysis (k(2)) of the Schiff bases formed between pyridoxal 5'-phosphat e and copolymers of L-lysine-L-tyrosine and L-lysine-L-phenylalanine, at different pH values, at temperature of 25 degrees C and an ionic st rength of 0.1 M. The values of the rate constant of formation obtained for the systems of the present work are greater than these for the PL P-poly-L-lysine system in all the range of pH studied, due to the pres ence of aromatic groups in the lateral chains of the polypeptide. The existence of these groups favors the presence of a few polar environme nt for the Schiff bases.