Selective delipidation of the plasma membrane by surfactants: Enrichment of sterols and activation of ATPase

Journal Article · Tue Aug 01 00:00:00 EDT 1989 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.90.4.1524· OSTI ID:6611835

Sandstrom, R P; Cleland, R ^[1]

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1. Portland State Univ., OR (USA) Univ. of Washington, Seattle (USA)

The influence of plasma membrane lipid components on the activity of the H{sup +}-ATPase has been studied by determining the effect of surfactants on membrane lipids and ATPase activity of oat (Avena sativa L.) root plasma membrane vesicles purified by a two-phase partitioning procedure. Triton X-100, at 25 to 1 (weight/weight) Triton to plasma membrane protein, an amount that causes maximal activation of the ATPase in the ATPase assay, extracted 59% of the membrane protein but did not solubilize the bulk of the ATPase. The Triton-insoluble proteins had associated with them, on a micromole per milligram protein basis, only 14% as much phospholipid, but 38% of the glycolipids and sterols, as compared with the native membranes. The Triton insoluble ATPase could still be activated by Triton X-100. When solubilized by lysolecithin, there were still sterols associated with the ATPase fraction. Free sterols were found associated with the ATPase in the same relative proportions, whether treated with surfactants or not. We suggest that surfactants activate the ATPase by altering the hydrophobic environment around the enzyme. We propose that sterols, through their interaction with the ATPase, may be essential for ATPase activity.

• OSTI ID: 6611835
• Journal Information: Plant Physiology; (USA), Journal Name: Plant Physiology; (USA) Vol. 90:4; ISSN 0032-0889; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ACID ANHYDRASES
ATP-ASE
BIOLOGICAL EFFECTS
BIOLOGICAL FUNCTIONS
CELL CONSTITUENTS
CELL MEMBRANES
CEREALS
ENZYME ACTIVITY
ENZYMES
FUNCTIONS
GRASS
HYDROLASES
HYDROXY COMPOUNDS
LILIOPSIDA
MAGNOLIOPHYTA
MEMBRANE PROTEINS
MEMBRANES
OATS
ORGANIC COMPOUNDS
PHOSPHOHYDROLASES
PLANTS
PROTEINS
ROOTS
STEROIDS
STEROLS
SURFACTANTS