States of amino acid residues in proteins: V. Different reactivities with H2O2 of tryptophan residues in lysozyme, proteinases and zymogens

摘要: Abstract Hydrogen and organic peroxides were examined in a search for reagent to differentiate between various states of tryptophan residues proteins. peroxide solution 0.5 M bicarbonate buffer (pH 8.1–9.4) containing 10% dioxane was found possess moderate oxidizing power oxidize free bound at different concentrations H2O2, the strength absorption band protein lowered stepwise with increasing concentration. By use this reagent, several proteins classified into types oxidizabilities, moles, n, each type per mole proteine determined; n=5 1 lysozyme (EC 3.2.1.17), n=5, chymotrypsinogen α-chymotrypsin 3.4.4.5), n=2, trypsinogen trypsin 3.4.4.4.) which are arranged order decreasing oxidizability. On activation chymotrypsinogen, oxidizability most strongly residue decreased greatly whereas, on trypsinogen, secondly oxidized increased slightly. The structural rearrangement discussed terms these changes state as well those other amino acids determined previously. enzymic activity an proteinases also measured function H2O2 concentration, results correlated degree oxidation residues. All denatured low concentration so that is applicable determination molar content protein.