Isolation and assay of corn root membrane vesicles with reduced proton permeability

David S. Perlin, Roger M. Spanswick

Research output: Contribution to journalArticle

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Abstract

Conditions promoting the formation of sealed membrane vesicles from corn roots with reduced proton permeability were examined using the probe 9-aminoacridine as a rapid indicator of pH gradient formation and dissipation. Plasma membrane vesicles isolated by differential and density gradient centrifugation were leaky to protons and rapidly equilibrated when exposed to artificially imposed pH gradients. The leaky plasma membrane vesicles showed reduced proton permeability when incubated with calcium or with excess phospholipids. However, these vesicles were unable to form ATP-induced pH gradients. Sealed vesicles isolated by discontinuous Ficoll gradient centrifugation of a microsomal fraction displayed reduced proton permeability and were osmotically active. In contrast to purified plasma membrane vesicles, the microsomal-derived vesicles were more suitable for studies of active proton transport.

Original languageEnglish (US)
Pages (from-to)178-186
Number of pages9
JournalBBA - Biomembranes
Volume690
Issue number2
DOIs
Publication statusPublished - Sep 9 1982

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All Science Journal Classification (ASJC) codes

  • Biophysics
  • Biochemistry
  • Cell Biology

Keywords

  • (Zea mays, Sealed vesicle)
  • 9-Aminoacridine
  • Divalent cation
  • Membrane vesicle
  • Phospholipid
  • Proton permeability
  • pH gradient

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