title: Identification of tryptophan 62 as an ozonization-sensitive residue in hen egg-white lysozyme.
abstract: The position of a single N'-formylkynurenine residue in ozone-inactivated hen egg-white lysozyme [EC 3.2.1.17] was determined by two methods. One involved identification of an amino-terminus of the C-peptide obtained by selective cleavage with hydrazine of the kynurenyl peptide linkage in oxidized lysozyme. The other was to analyze a tryptic peptide containing kynurenine in the modified enzyme. Both methods showed that tryptophan 62 in lysozyme was so sensitive to ozone as to be selectively oxidized to N'-formylkynurenine with concomitant loss of the lytic activity.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D004529:Egg White; D007737:Kynurenine / Q000032:analysis; D009113:Muramidase; D010126:Ozone; D010446:Peptide Fragments / Q000032:analysis; D014364:Tryptophan / Q000032:analysis*
chemical_list: D000596:Amino Acids; D010446:Peptide Fragments; D007737:Kynurenine; D010126:Ozone; D014364:Tryptophan; D009113:Muramidase