Schiff bases of poly-L-lysine and some compounds of the vitamin B-6 group. Influence of polypeptidic structure

Abstract

The apparent rate constants of formation (k(1)) and hydrolysis (k(2)) of the Schiff bases formed between pyridoxal and poly-L-lysine has been fitted to a kinetic scheme that involves the different protonated species in the reaction medium and the individual rate constants of formation (k(1)(i)) and hydrolysis (k(2)(i)). A Bronsted plot with alpha = 0.67 is in accord with an acid catalytic intramolecular process. The effects of hydrophobic medium due to the presence of the macromolecule on the formation and hydrolysis of Schiff bases from FL, DPL and PLP with poly-L-lysine is discussed.