Charge transfer between tryptophan and tyrosine in casein: a pulse radiolysis study Original Research Article

Charge transfer from tyrosine to tryptophan radicals in bovine milk casein, as observed using pulse radiolysis technique, is reported. The reactions of casein with hydroxyl, azide, Br2radical dot− and CCl3O2radical dot radicals have also been studied. Radical transformation was found to take place at a rate of 1.5×104 s−1. The effect of pH, oxidising radical and the proximity of tyrosine and tryptophan on this radical transformation, as well as repair of the casein radical by ascorbate, have also been studied.