title: [Influence of inorganic phosphate on the production of free radicals in UV-irradiated frozen tyrosine solutions].
abstract: The role of inorganic phosphate as a catalyzer of the production of tyrosyl radical in frozen tyrosine solutions irradiated with near UV light at 77K has been demonstrated by the EPR method. It was shown that the increase in the yield of tyrosyl radicals at pH < 7 correlates with the production of H* atoms and can be explained by the fact that phosphate acts as an acceptor of photoejected electrons. At pH > 7, the increase in the yield of tyrosyl radicals is accompanied by the production of phosphate radicals and OH* and is caused, presumably, by the catalysis of the formation of triplet states of tyrosine molecules by the HPO4(2-) form of phosphate, the fact shown by a number of authors. A quantitative estimation of relative concentrations of photosensitized paramagnetic products was carried out on the basis of computer analysis of resultant EPR signals.
authors.forename: T A
authors.initials: TA
authors.lastname: Lozinova
authors.forename: A V
authors.initials: AV
authors.lastname: Lander
mesh_terms: D005615:Freezing; D017665:Hydroxyl Radical / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D014443:Tyrosine / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D010710:Phosphates; D017665:Hydroxyl Radical; D014443:Tyrosine