title: Oxygen radical induced alterations in polyclonal IgG.
abstract: In the sera and synovial fluid of patients with rheumatoid arthritis, part of the IgG fraction is found in an aggregated and fluorescent form. Oxygen-free radicals have been implicated in this denaturation, although the precise radical species responsible is unknown. In this work, oxygen-free radicals generated radiolytically were allowed to attack polyclonal IgG in solution. OH radicals induced aggregation of the monomer and a new fluorescence appeared in the visible region (Ex 360 nm, Em 454 nm). The superoxide radical anion was found to be inert in both these respects, whilst peroxy radicals induced autofluorescence without concomitant aggregation. The results suggest that OH.and/or peroxy radical attack may be an in vivo mechanism for IgG denaturation.
authors.affiliation: Department of Biochemistry, Selly Oak Hospital, Birmingham, England.
authors.forename: H R
authors.initials: HR
authors.lastname: Griffiths
authors.forename: J
authors.initials: J
authors.lastname: Lunec
authors.forename: C A
authors.initials: CA
authors.lastname: Gee
authors.forename: R L
authors.initials: RL
authors.lastname: Willson
mesh_terms: D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005453:Fluorescence; D005609:Free Radicals; D005720:Gamma Rays; D006801:Humans; D006878:Hydroxides / Q000494:pharmacology*; D017665:Hydroxyl Radical; D007074:Immunoglobulin G; D046911:Macromolecular Substances; D010545:Peroxides / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D013481:Superoxides / Q000494:pharmacology*
chemical_list: D005609:Free Radicals; D006878:Hydroxides; D007074:Immunoglobulin G; D046911:Macromolecular Substances; D010545:Peroxides; D013481:Superoxides; C049375:perhydroxyl radical; D017665:Hydroxyl Radical