ANTIGENIC DETERMINANTS OF THE MEMBRANE-BOUND HYDROGENASE IN ALCALIGENES-EUTROPHUS ARE EXPOSED TOWARD THE PERIPLASM

Electron microscopic immunogold labeling experiments were performed wi th ultrathin sections of plasmolyzed cells of Alcaligenes eutrophus an d ''whole-mount'' samples of spheroplasts and protoplasts. They demons trated that antigenic determinants of the membrane-bound hydrogenase a re exposed, at the outside of the cytoplasmic membrane, to the peripla sm.