title: The lipid fluidity of rat liver membrane subfractions.
abstract: 1. The lipid fluidity of three major rat liver plasma-membrane subfractions, as well as Golgi apparatus and endocytic fractions, was assessed with a fatty acid spin probe by using e.s.r. techniques. 2. The sinusoidal (blood-facing) plasma-membrane subfraction was the most fluid of the three plasma-membrane regions. Fractions originating from the bile-canalicular and contiguous (lateral) regions were most rigid. Endocytic fractions isolated (endosomes and diacytosomes) were of a similar fluidity to fractions originating from the sinusoidal plasma-membrane region. By far the most fluid fractions examined were derived from the Golgi-apparatus complex. 3. The three plasma-membrane subfractions each showed a different response to the bilayer-fluidizing effect of benzyl alcohol. 4. Arrhenius-type plots of the order parameter S and outer hyperfine splitting, 2T( parallel), identified lipid-phase separations in the plasma-membrane subfractions.
authors.affiliation: Paterson Laboratories, Christie Hospital and Holt Radium Institute, Withington, Manchester M20 9BX, U.K.
authors.forename: A D
authors.initials: AD
authors.lastname: Whetton
authors.forename: M D
authors.initials: MD
authors.lastname: Houslay
authors.forename: N J
authors.initials: NJ
authors.lastname: Dodd
authors.forename: W H
authors.initials: WH
authors.lastname: Evans