Display options
Share it on

Plant Physiol. 1976 Dec;58(6):703-9. doi: 10.1104/pp.58.6.703.

Protein Bodies from the Endosperm of Castor Bean: Subfractionation, Protein Components, Lectins, and Changes during Germination.

Plant physiology

R J Youle, A H Huang

Affiliations

  1. Department of Biology, University of South Carolina, Columbia, South Carolina 29208.

PMID: 16659749 PMCID: PMC542291 DOI: 10.1104/pp.58.6.703

Abstract

Protein bodies from the storage endosperm of dry castor bean (Ricinus communis L.) were isolated by successive nonaqueous linear density gradient centrifugation. The isolated protein bodies were lysed by the addition of water, and the various structural components of the organelles were separated by sucrose gradient centrifugation. The matrix protein remained at the top of the gradient while the membrane, the crystalloids, and the globoids migrated to densities 1.15 g/cm(3), 1.30 g/cm(3), and > 1.46 g/cm(3), respectively. The protein of the protein bodies was distributed evenly between the crystalloids and the matrix, and little protein was present in the globoids or the membrane.The proteins of the protein bodies were resolved into protein components of diverse molecular weights in sodium dodecyl sulfate-acrylamide gel electrophoresis. The protein components of the organelle matrix were distinct from those of the crystalloids. Whereas the matrix proteins had very diverse molecular weights, the crystalloid proteins were mainly composed of several proteins with molecular weights between 50,000 and 60,000 daltons. Also, the matrix proteins were soluble in water while the crystalloid proteins were insoluble in water but soluble in salt solution, thus representing albumins and globulins, respectively. Two of the matrix proteins with molecular weights approximately 120,000 and 65,000 daltons were identified as the phytohemagglutimin and the toxic protein ricin, respectively.During germination, the crystalloid proteins served as the storage protein and went through rapid degradation with smaller polypeptides formed as intermediates. In contrast, the proteins of the matrix under-went a much slower degradation during the same period and did not appear to be storage protein.

References

  1. Nature. 1970 Oct 3;228(5266):81-2 - PubMed
  2. Arch Biochem Biophys. 1968 Feb;123(2):255-64 - PubMed
  3. Annu Rev Biochem. 1973;42(0):541-74 - PubMed
  4. Plant Physiol. 1975 Jun;55(6):1031-7 - PubMed
  5. Plant Physiol. 1969 Nov;44(11):1488-98 - PubMed
  6. Plant Physiol. 1963 Mar;38(2):139-44 - PubMed
  7. J Cell Sci. 1975 Oct;19(1):157-67 - PubMed
  8. Plant Physiol. 1973 Aug;52(2):98-104 - PubMed
  9. Arch Biochem Biophys. 1968 Mar 20;124(1):199-205 - PubMed
  10. Plant Physiol. 1975 Aug;56(2):292-9 - PubMed
  11. Plant Physiol. 1971 Nov;48(5):637-41 - PubMed
  12. Biochem J. 1973 Nov;136(3):677-83 - PubMed
  13. J Biol Chem. 1974 Feb 10;249(3):803-10 - PubMed
  14. Plant Physiol. 1967 Jun;42(6):797-813 - PubMed
  15. J Cell Biol. 1963 Apr;17:208-12 - PubMed
  16. J Biol Chem. 1951 Nov;193(1):265-75 - PubMed
  17. J Biophys Biochem Cytol. 1958 Jan 25;4(1):47-54 - PubMed
  18. Biochemistry. 1974 Jan 1;13(1):196-204 - PubMed

Publication Types