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Determination of the Rates of Formation and Hydrolysis of the Schiff Bases Formed by Pyridoxal 5′‐Phosphate with Copolypeptides Containing L ‐Lysine and Aromatic L ‐Amino Acids
Author(s) -
EchevarríaGorostidi Gerardo R.,
Pérez M. Piedad Martín,
Santos José G.,
Blanco Francisco García
Publication year - 1999
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/(sici)1522-2675(19990505)82:5<769::aid-hlca769>3.0.co;2-t
Subject(s) - chemistry , hydrolysis , pyridoxal , ionic strength , phenylalanine , tryptophan , schiff base , pyridine , aromatic amino acids , reaction rate constant , phosphate , pyridoxal phosphate , lysine , stereochemistry , polymer chemistry , medicinal chemistry , amino acid , organic chemistry , kinetics , enzyme , cofactor , biochemistry , aqueous solution , physics , quantum mechanics
The apparent rate constants of formation ( k 1 ) and hydrolysis ( k 2 ) of the Schiff bases formed between pyridoxal 5′‐phosphate and the poly( L ‐Lys, L ‐Trp)4 : 1 copolymer at different pH values, a temperature of 25 °C and an ionic strength of 0.1 M were determined. The individual rate constants of formation and hydrolysis of the Schiff bases of pyridoxal 5′‐phosphate with poly( L ‐Lys, L ‐Trp)4 : 1, poly( L ‐Lys, L ‐Tyr)4 : 1, and poly( L ‐Lys, L ‐Phe)1 : 1 corresponding to the different chemical species present in the medium as a function of its acidity were also determined, as were the p K values for the Schiff bases. The significance of the interactions between the pyridine ring in pyridoxal 5′‐phosphate and the aromatic ring in the L ‐phenylalanine, L ‐tyrosine, and L ‐tryptophan side chains is demonstrated.