title: Subzero temperature study of the inner mitochondrial membrane and related phospholipid membrane systems with the fluorescent probe, trans-parinaric acid.
abstract: The fluorescence intensity of trans-parinaric acid as a function of the temperature indicates a phase transition in bovine heart mitochondrial inner membranes below 0 degrees C. The comparison of the dye fluorescence intensity in intact inner mitochondrial membranes and in vesicles from extracted phospho lipids of mitochondria revealed a similar intensity increase with decreasing temperature. A synthetic phospholipid system of dioleoyl phosphatidylcholine was investigated because of its low phase transition temperature and showed a very definite intensity change at -25 degrees C. trans-Parinaric acid in membrane systems probes an environment of intermediate polarity; this was found from the excitation and emission spectra and from fluorescence decay.
mesh_terms: D000818:Animals; D002417:Cattle; D005231:Fatty Acids, Unsaturated; D005456:Fluorescent Dyes; D005615:Freezing; D007425:Intracellular Membranes / Q000648:ultrastructure*; D008563:Membrane Lipids / Q000032:analysis*; D008929:Mitochondria, Heart / Q000648:ultrastructure*; D010743:Phospholipids / Q000032:analysis*; D013050:Spectrometry, Fluorescence
chemical_list: D005231:Fatty Acids, Unsaturated; D005456:Fluorescent Dyes; D008563:Membrane Lipids; D010743:Phospholipids; C013641:parinaric acid