title: Plasma membranes from Candida tropicalis grown on glucose or hexadecane. I. Isolation, identification and purification.
abstract: Plasma membranes from Candida tropicalis grown on glucose or hexadecane were isolated using a method based on the difference in surface charge of mitochondria and plasma membranes. After mechanical disruption of the cells, a fraction consisting of mitochondrial and plasma membrane vesicles was obtained by differential centrifugation. Subsequently the mitochondria were separated from the plasma membrane vesicles by aggregation of the mitochondria at a pH corresponding to their isoelectric point. Additional purification of the isolated plasma membrane vesicles was achieved by osmolysis. Surface charge densities of mitochondria and plasma membranes were determined and showed substrate-dependent differences. The isolated plasma membranes were morphologically characterized by electron microscopy and, as a marker enzyme, the activity of Mg2+-dependent ATPase was determine. By checking for three mitochondrial marker enzymes the plasma membrane fractions were estimated to be 94% pure with regard to mitochondrial contamination.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000473:Alkanes / Q000378:metabolism*; D002175:Candida / Q000378:metabolism / Q000648:ultrastructure*; D002458:Cell Fractionation / Q000379:methods; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure*; D005614:Freeze Fracturing; D005947:Glucose / Q000378:metabolism*; D007700:Kinetics; D008564:Membrane Potentials; D008854:Microscopy, Electron; D008928:Mitochondria / Q000648:ultrastructure
chemical_list: D000473:Alkanes; D000251:Adenosine Triphosphatases; C007932:n-hexadecane; D005947:Glucose