Skip to main content
NCBI home page
Biophysical Journal logoLink to Biophysical Journal
. 1978 May;22(2):341–346. doi: 10.1016/S0006-3495(78)85492-7

The effects of calcium2+ and magnesium2+ on the electrophoretic mobility of chromaffin granules measured by electrophoretic light scattering.

D P Siegel, B R Ware, D J Green, E W Westhead
PMCID: PMC1473435  PMID: 656547

Abstract

Electrophoretic light scattering was used to determine the electrophoretic mobility distributions of isolated bovine adrenal chromaffin granules as a function of divalent metal ion concentrations. Changes in the electrophoretic mobility reflected changes in the surface charge density of the granules. Ca2+ and Mg2+ (0.10--2.0 mM) were equally effective in reducing the electrophoretic mobilities. These findings are consistent with recent studies of the binding of Ca2+ and Mg2+ to the surface of chromaffin granules and are further evidence that the specific role of Ca2+ in exocytosis is due to effects other than the ability of Ca2+ to decrease the electrostatic repulsion between negatively charged membranes.

Full text

PDF
341

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Dean P. M. Exocytosis modelling: an electrostatic function for calcium in stimulus-secretion coupling. J Theor Biol. 1975 Oct;54(2):289–308. doi: 10.1016/s0022-5193(75)80132-9. [DOI] [PubMed] [Google Scholar]
  2. Dean P. M., Matthews E. K. Calcium-ion binding to the chromaffin-granule surface. Biochem J. 1974 Sep;142(3):637–640. doi: 10.1042/bj1420637. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Douglas W. W. Involvement of calcium in exocytosis and the exocytosis--vesiculation sequence. Biochem Soc Symp. 1974;(39):1–28. [PubMed] [Google Scholar]
  4. Douglas W. W., Rubin R. P. The mechanism of catecholamine release from the adrenal medulla and the role of calcium in stimulus-secretion coupling. J Physiol. 1963 Jul;167(2):288–310. doi: 10.1113/jphysiol.1963.sp007150. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Eagles P. A., Johnson L. N., Van Horn C. The distribution of anionic sites on the surface of the chromaffin granule membrane. J Ultrastruct Res. 1976 Apr;55(1):87–95. doi: 10.1016/s0022-5320(76)80084-6. [DOI] [PubMed] [Google Scholar]
  6. Edwards W., Phillips J. H., Morris S. J. Structural changes in chromaffin granules induced by divalent cations. Biochim Biophys Acta. 1974 Jul 31;356(2):164–173. doi: 10.1016/0005-2736(74)90280-6. [DOI] [PubMed] [Google Scholar]
  7. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  8. Matthews E. K., Evans R. J., Dean P. M. The ionogenic nature of the secretory-granule membrane. Electrokinetic properties of isolated chromaffin granules. Biochem J. 1972 Dec;130(3):825–832. doi: 10.1042/bj1300825. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Morris S. J., Schober R. Demonstration of binding sites for divalent and trivalent ions on the outer surface of chromaffin-granule membranes. Eur J Biochem. 1977 May 2;75(1):1–12. doi: 10.1111/j.1432-1033.1977.tb11498.x. [DOI] [PubMed] [Google Scholar]
  10. Schober R., Nitsch C., Rinne U., Morris S. J. Calcium-induced displacement of membrane-associated particles upon aggregation of chromaffin granules. Science. 1977 Feb 4;195(4277):495–497. doi: 10.1126/science.835010. [DOI] [PubMed] [Google Scholar]
  11. Trifaró J. M., Dworkind J. A new and simple method for isolation of adrenal chromaffin granules by means of an isotonic density gradient. Anal Biochem. 1970 Apr;34(2):403–412. doi: 10.1016/0003-2697(70)90125-9. [DOI] [PubMed] [Google Scholar]

Articles from Biophysical Journal are provided here courtesy of The Biophysical Society

RESOURCES