Mechanism of Reaction of Proteins with Reactive Dyes:II—Reactivity of Simple Model Compounds with Chlorotriazine Dyes

The chemistry of the functional groups in wool is described and the selection of appropriate model compounds for them is discussed. The measurement of the reactivities of these model compounds and possible mechanisms of their reactions are discussed. The nucleophilic anion is the important species in the reaction of a chlorotriazine dye with the thiol group in cysteine or the hydroxyl and phenolic groups in serine, threonine and tyrosineresidues. The reaction of a chlorotriazine dye with the amino groups of lysine and the N ‐terminal amino acids, with the imidazole group of histidine and with the guanidinogroup of arginine takes place mainly with the unprotonated base. Evidence in support of these mechanisms is provided by an investigation of the reactions of the dye with aqueous ammonia and anhydrous liquid ammonia.