title: Isolation and electrophoretic characterization of the plasma membrane of sea-urchin sperm.
abstract: A subcellular fraction containing plasma membranes was isolated from flagella of the sperm of Strongylocentrotus purpuratus by differential centrifugation, and analysed by sodium dodecyl sulphate/polyacrylamide gel electrophoresis. Coomassie Blue staining revealed nine major bands and 14 minor species. Five bands of apparent molecular weights approximately 200 X 10(3), 149 X 10(3), 120 X 10(3), 75 X 10(3) and 59 X 10(3) also stained with periodic acid-Schiff's reagent and so are probably glycoproteins. These five components are externally exposed, as determined by lactoperoxidase-catalysed radio-iodination. Isolation of membranes from radio-iodinated sperm results in an enrichment of about tenfold in the specific activity of 125I. Comparison of the electrophoretic patterns of labelled sperm and of the membranes isolated from 125I-labelled sperm suggests that no major labelled proteins are lost during the isolation procedure, and so to this extent the membrane fraction is representative of the entire sperm plasma membrane.
mesh_terms: D000818:Animals; D002458:Cell Fractionation; D002462:Cell Membrane / Q000032:analysis / Q000648:ultrastructure; D003576:Electron Transport Complex IV / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D007457:Iodine Radioisotopes; D008297:Male; D008565:Membrane Proteins / Q000032:analysis; D008854:Microscopy, Electron; D008970:Molecular Weight; D012617:Sea Urchins; D013082:Sperm Tail / Q000032:analysis* / Q000648:ultrastructure; D013094:Spermatozoa / Q000032:analysis*
chemical_list: D007457:Iodine Radioisotopes; D008565:Membrane Proteins; D003576:Electron Transport Complex IV