Abstract
The D-[5-3H] glucose-binding membrane proteins in rat islet homogenate and its F2 fraction obtained by sucrose gradient (d20=1.00-1.18) ultracentrifugation at 70000g for 2 hr were analyzed by SDS-polyacrylamide gel electrophoresis. Five components in the F2 fraction, which contains membrane proteins related to glucose-induced insulin release, showed relative mobilities of around 0.75 on SDS gel stained with Coomassie brilliant blue (R-250), and had apparent molecular weights of 22000-30000. One component among them appeared to be a glycoprotein because it was sensitive to the periodic acid-Schiff reagent (PAS reagent).
