An Epitope Recognized by the Monoclonal Antibody MR-21 which is Reactive with the Cell Surface of Chattonella marina Type II

Abstract

The monoclonal antibody MR-21 was strongly reactive with the cells of Chattonella marina NIES-121 belonging to Type II. MR-21 reacted with several bands on the nitrocellulose sheet after the cell lysate was developed using the Western blotting method. Antigens were inactivated by periodate-oxidation, but not by heating, proteinase, nor enzymes hydrolyzing sugars. Electron microscopic observation of immunogold-stained ultrathin section of the cells revealed that the antigens were localized at the secretory vesicles and Golgi systems as well as on the cell surface. These results suggest that the antigen molecules which MR-21 recognizes may be glycoproteins, and the epitope may be in the carbohydrate side chains.