Electrokinetic properties of dissociated chick embryo cells. II. Calcium ion binding by neural retinal cells
✍ Scribed by Collins, Michael
- Publisher
- John Wiley and Sons
- Year
- 1966
- Tongue
- English
- Weight
- 898 KB
- Volume
- 163
- Category
- Article
- ISSN
- 0022-104X
No coin nor oath required. For personal study only.
✦ Synopsis
Since embryonic cells may be bound together by calcium ions forming bridges between negatively charged sites on the cellular surfaces, it is important to show that embryonic cells can bind calcium ions and to learn something of that binding. Neural retinal cells from seven-day chick embryos have been dissociated and prepared for microscopic electrophoresis in three different ways. Their electrophoretic mobilities and surface charge densities have been determined over a range of calcium concentrations. The progressive reduction of charge density with increasing calcium concentration, with ionic strength he2d constant, clearly indicates calcium binding at the cellular surface.
The data contained herein permit one to calculate a binding constant for the calcium-binding site complex, the number of sites per cell surface, the average distance between them, the percentage of sites occupied by calcium ions at physiological calcium concentration, and the fraction of anionic sites on the cell surface which bind calcium. They also indicated that trypsin dissociation may remove calciumbinding material from cellular surfaces and suggest that that material may be regenerated during incubation in culture medium.