Identification of the proteins exposed on the cytoplasmic surface of the pancreatic zymogen granule.


Lactoperoxidase-catalyzed 125I-iodination was used to label pancreatic zymogen granules. Membrane proteins facing the cytoplasmic surface were specifically labeled. Two low molecular weight proteins of 17 000 and 15 000 were intensely labeled at 0 degree C. Another small 13 kDa protein was strongly iodinated at 25 degrees C along with some others, including… (More)