title: Trypanosoma brucei: a fluorescence and spin label study of the membranes of the bloodstream form.
abstract: Fluidity of the plasma membrane of Trypanosoma brucei brucei has been examined with fluorescence and electron spin resonance spectroscopy. Fluorescent probes 1,6-diphenyl-1,3,5-hexatriene and 8-anilino-1-naphthalene sulfonate and the spin label probe 5-doxyl stearate have been employed to examine fluidity under a variety of conditions. The temperature dependence of 8-anilino-1-naphthalene sulfonate polarization and of the order parameter S for 5-doxyl stearate reveals phase alterations near 30 C. 1,6-Diphenyl-1,3,5-hexatriene polarization shows that proteolysis of the surface glycoprotein with trypsin increases fluidity but treatment with human serum which is trypanocidal produces no detectable change in membrane fluidity.
mesh_terms: D000818:Animals; D001769:Blood; D002417:Cattle; D002462:Cell Membrane / Q000502:physiology; D005454:Fluorescence Polarization; D006023:Glycoproteins / Q000502:physiology; D006801:Humans; D008560:Membrane Fluidity; D008565:Membrane Proteins / Q000502:physiology; D013113:Spin Labels; D013696:Temperature; D014346:Trypanosoma brucei brucei / Q000502:physiology*; D014357:Trypsin / Q000378:metabolism
chemical_list: D006023:Glycoproteins; D008565:Membrane Proteins; D013113:Spin Labels; D014357:Trypsin