title: Heterogeneous distribution of enzymes among plasma-membrane fragments sedimenting with the microsomal fraction of rat liver.
abstract: Plasma-membrane fragments recovered in the microsomal fraction of rat liver homogenates were shown to be heterogeneous in density. It was demonstrated that 5'-nucleotidase, the most commonly used plasma-membrane marker, is concentrated in the lightest subfraction. Two of the published procedures for the isolation of plasma-membrane fragments from the microsomal fraction (Touster et al., 1970; Hinton et al., 1971) are shown to give products which are not representative of all the plasma-membrane fragments of microsomal size, and it is argued that a third procedure (House & Weidemann, 1970) is likely to give a similar product.
mesh_terms: D000227:Adenine Nucleotides; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D002458:Cell Fractionation / Q000379:methods; D002462:Cell Membrane / Q000201:enzymology*; D002499:Centrifugation, Density Gradient; D005952:Glucose-6-Phosphatase / Q000032:analysis; D008099:Liver / Q000201:enzymology*; D008862:Microsomes, Liver / Q000201:enzymology*; D009708:Nucleotidases / Q000032:analysis*; D010727:Phosphoric Diester Hydrolases / Q000032:analysis; D012313:RNA / Q000032:analysis; D051381:Rats; D014461:Ultracentrifugation
chemical_list: D000227:Adenine Nucleotides; D012313:RNA; D009708:Nucleotidases; D000469:Alkaline Phosphatase; D005952:Glucose-6-Phosphatase; D010727:Phosphoric Diester Hydrolases