Rate Constants of Hydrated Electron Reactions with Amino Acids

Abstract

The rate constants for reactions between the hydrated electron and amino acids was measured in aqueous deaerated solutions at different pH''s. Cystine, cysteine, and the positive histidine ion were very reactive at neutral pH. Asparagine, arginine, and the 3 aromatic amino acids; phenylalanine, tryptophan, and tyrosine, were moderately active. Other common amino acids were unreactive. With increasing pH, reactivity always decreased. Compounds effective as chemical protecting agents with sulfhydryl or disulfide groups showed high reactivity at neutral pH.