Charge and Ion-Binding Differences Between Corneal Epithelial and Endothelial Antigens

Abstract

Summary

The experimental evidence described in this report shows that the electrophoretic mobility differences between epithelial and endothelial proteins appear to be a general phenomenon for mammalian corneal tissues. The characteristic behavior in an electrical field of epithelial and endothelial proteins was demonstrated to be a result of net charge rather than molecular-size differences by using agar and polyacrylamide as support media for electrophoresis. In both techniques the majority of endothelial proteins was grouped closer to the anode.

Data are given to show that the observed net-charge differences are reflected in the ion-exchange properties of epithelial and endothelial protoplasmic proteins. In the cell-free environment, the endothelial macromolecules bound about ten times more K⁺ than the epithelial macromolecules. These binding differences could account, at least partially, for the net accumulation of ions against an “apparent concentration gradient.”

We wish to thank Dr. Raymond Damadian for his interest in this work and his helpful suggestions in regard to equilibrium dialysis experiments.