Isolation and Characterization of the Protein Body Membrane of Castor Beans
Open Access
- 1 September 1979
- journal article
- research article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 64 (3), 506-511
- https://doi.org/10.1104/pp.64.3.506
Abstract
Intact protein bodies were isolated from dry castor bean seeds (Ricinus communis L.) after homogenization in nonaqueous medium. After repeated washing with glycerol to remove trapped lipid globules, the soluble matrix proteins were removed by the addition of aqueous buffer. The membrane remained attached to the insoluble protein crystalloids and was subsequently released by sonication. Purification of the membrane vesicles in a sucrose gradient produced a single band at a density of 1.21 grams per cubic centimeter. Treatment with 6 molar urea, 1 molar KCl, or 0.25 molar galactose had no effect on the equilibrium density of the membrane. Electron microscopy revealed a highly pure and uniform collection of membrane vesicles. No enzyme activity was specifically associated with the membrane. Sodium dodecyl sulfate gel electrophoresis of the protein body fractions showed that the membrane contained unique proteins, two of which were glycosylated. The membrane contained 153 nanomoles of phospholipid per milligram of protein. The composition of the phosphoglycerides was 51% ethanolamine, 41% choline, 8% inositol, and a trace of serine.Keywords
This publication has 21 references indexed in Scilit:
- Lipase Activities in Castor Bean Endosperm during GerminationPlant Physiology, 1974
- [36] Purification of a plasma membrane-bound adenosine triphosphatase from plant rootsMethods in Enzymology, 1974
- Characterization of two plant lectins from Ricinus communis and their quantitative interaction with a murine lymphomaBiochemistry, 1974
- Membrane-bound Adenosine Triphosphatase Activities of Oat RootsPlant Physiology, 1973
- Freeze-etch studies of protein bodies in wheat scutellumJournal of Ultrastructure Research, 1972
- Electrophoretic analysis of the major polypeptides of the human erythrocyte membraneBiochemistry, 1971
- A low-viscosity epoxy resin embedding medium for electron microscopyJournal of Ultrastructure Research, 1969
- Association of lysosomal activity with aleurone grains in plant seedsArchives of Biochemistry and Biophysics, 1968
- A RAPID METHOD OF TOTAL LIPID EXTRACTION AND PURIFICATIONCanadian Journal of Biochemistry and Physiology, 1959
- Spectrophotometric measurements of the enzymatic formation of fumaric and cis-aconitic acidsBiochimica et Biophysica Acta, 1950