Chromogranin A ( Pituitary secretory protein I , CgA, SP-I, CHGA)

Chromogranin A is an acidic secretory protein consisting of 439 amino acids. The protein is found in a wide variety of hormone and neurotransmitter storage vesicles, and it is known be co-stored and co-relased with catecholamines from adrenal medulla and sympathetic neuronal vesicles during exocytosis.