[Aggregation of rhodopsin molecules during damaging exposure of photoreceptor membranes to light].
Injuring light induced structural changes in rod outer segment (ROS) membranes are studied using "ST EST spectroscopy" for spin labelled rhodopsin, ESR of lipid spin label and SDS gel-electrophoresis. Free SH-group content of rhodopsin and lipid peroxidation level were simultaneously determined as well. A decrease of rotational mobility of rhodopsin in ROS induced by prolonged illumination is shown to result from irreversible protein aggregation caused by disulfide bond formation between "hydrophobic" SH-groups of rhodopsin. Some decrease of lipid microviscosity and degree of order are found, in contrast to considerable rise in microviscosity due to Fe2+-ascorbate induced lipid peroxidation of ROS membranes. Lipid oxidation is found to accelerate protein aggregation which in its turn influences the state of lipid bilayer.
D000818:Animals; D004578:Electron Spin Resonance Spectroscopy; D066298:In Vitro Techniques; D008027:Light / Q000009:adverse effects*; D008563:Membrane Lipids / Q000378:metabolism; D010084:Oxidation-Reduction; D010777:Photochemistry; D010786:Photoreceptor Cells / Q000528:radiation effects*; D011896:Rana temporaria; D012168:Retinal Pigments / Q000378:metabolism*; D012243:Rhodopsin / Q000378:metabolism*; D012374:Rod Cell Outer Segment / Q000528:radiation effects*
D008563:Membrane Lipids; D012168:Retinal Pigments; D012243:Rhodopsin
Agregatsiia molekul rodopsina pri povrezhdaiushchem deĭstvii sveta na fotoretseptornye membrany.