title: Human chromogranin A. Purification and characterization from catecholamine storage vesicles of human pheochromocytoma.
abstract: Chromogranin A is the quantitatively major soluble protein in catecholamine storage vesicles of the adrenal medulla and sympathetic nerve, and has been a useful index of exocytosis during sympathoadrenal neurosecretion. To probe human catecholamine storage and release, we isolated chromogranin A from chromaffin tissue in human pheochromocytoma, and compared it to chromogranin A isolated from chromaffin tissue in bovine adrenal medulla. The preparation included catecholamine storage vesicle isolation by sucrose gradient centrifugation, removal of dopamine-beta-hydroxylase by affinity chromatography on Concanavalin A-Sepharose, and preparative polyacrylamide gel electrophoresis. Human and bovine chromogranin A displayed considerable interspecies homology. Human chromogranin A is a 68,000 dalton monomeric protein with an unusual amino acid composition (31.53 weight % glutamic acid); an acidic, microheterogeneous isoelectric point (4.57-4.68); a characteristic tryptic digest peptide map; and marked dissimilarity to dopamine-beta-hydroxylase in all properties studied. A new probe of human sympathoadrenal function is available in chromogranin A.
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000032:analysis* / Q000648:ultrastructure; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D002837:Chromaffin Granules / Q000032:analysis* / Q000648:ultrastructure; D002838:Chromaffin System / Q000032:analysis*; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis / Q000302:isolation & purification*; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007525:Isoelectric Focusing; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000302:isolation & purification*; D010673:Pheochromocytoma / Q000032:analysis* / Q000648:ultrastructure; D013045:Species Specificity
chemical_list: D000596:Amino Acids; C506150:CHGA protein, human; D053379:Chromogranin A; D002864:Chromogranins; D009419:Nerve Tissue Proteins; D004299:Dopamine beta-Hydroxylase