Binding of concanavalin a to nuclei of unsynchronized and synchronized HeLa cells

Abstract

Purified, intact HeLa cell nuclei were examined for specific Concanavalin A binding using a quantitative binding assay with novel refinements. The result was compared with the specific binding per micron 2 of Con A to RBC's and to HeLa plasma membranes. Con A binding to nuclei isolated from synchronized cells at several phases of the cell cycle was assessed and nuclei sized by Coulter Counter analysis. The Con A binding sites appear to be at the highest density just subsequent to mitosis, decreasing in density between early G 1 and late G 1 and rapidly decreasing between S and G 2. Mechanisms to explain this phenomenon are suggested: