title: Monoclonal antibodies to chromaffin cells can distinguish proteins specific to or specifically excluded from chromaffin granules.
abstract: I have prepared a number of monoclonal antibodies to chromaffin cell membranes. One of these antibodies recognizes a number of antigenically related proteins that are present in all tissues examined. In the adrenal, these proteins are completely excluded from chromaffin granules but are present in other subcellular membrane fractions. This non-granule membrane-specific antibody has been designated NG3. A second antibody, CG7, binds to a single protein which segregates specifically into chromaffin granules. The protein recognized by CG7 is cytochrome b561, or chromomembrin B, one of the major protein components of chromaffin granule membranes. CG7 also labels a protein (the identical cytochrome b561) in bovine posterior pituitary neurosecretory vesicle membranes indicating that it functions in both peptidergic and catecholaminergic secretory granules. These two monoclonal antibodies provide useful probes of both granule and extra-granule membrane proteins for studies of membrane trafficking in chromaffin cells.
mesh_terms: D000313:Adrenal Medulla / Q000294:innervation; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D002417:Cattle; D002837:Chromaffin Granules / Q000276:immunology*; D002838:Chromaffin System / Q000276:immunology*; D003573:Cytochrome b Group / Q000276:immunology; D004759:Enterochromaffin Cells / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D008565:Membrane Proteins / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D003573:Cytochrome b Group; D000939:Epitopes; D008565:Membrane Proteins; C023646:cytochrome b561