Abstract
The cell surface proteins of AH-66 hepatoma ascites cells were examined both by fluorescent labeling with cycloheptaamylose-fluorescamine complex and by radioiodination with lacto-peroxidase. The labeled proteins were analyzed by measuring the distribution of fluorescence or radioactivity in polyacrylamide gels after electrophoresis. Although the degree of fluores-cent labeling with cycloheptaamylose-fluorescamine complex was substantially different from that obtained by lactoperoxidase-catalyzed iodination, proteins with molecular weights of 130, 000, 90, 000, 86, 000, 50, 000-60, 000, and 37, 000 were strongly labeled in common by both reagents. It is suggested that at least these proteins are exposed on the surface of the plasma membranes of AH-66 cells. One of these proteins labeled strongly by both reagents is the major glycoprotein, with an apparent molecular weight of 130, 000 in 10% polyacrylamide gels.
