Strongly inhibits glucose induced insulin release from the pancreas. Inhibits low calcium-stimulated parathyroid cell secretion. Inhibits catecholamine release from chromaffin cells and noradrenergic neurons by acting as a non-competitive nicotinic cholinergic antagonist. Can induce mast cell migration, degranulation and production of cytokines and chemokines. Regulates granule biogenesis in endocrine cells by up-regulating the transcription of protease nexin 1 (SERPINE2) via a cAMP-PKA-SP1 pathway. This leads to inhibition of granule protein degradation in the Golgi complex which in turn promotes granule formation. Interacts with SCG3. Pyroglutaminated serpinin localizes to secretory vesicle. Associated with the secretory granule membrane through direct interaction to SCG3 that in turn binds to cholesterol-enriched lipid rafts in intragranular conditions. In pituitary gonadotropes, located in large secretory granules. O-glycosylated. Parathyroid CHGA is sulfated on tyrosine residues, whereas adrenal CHGA seems to be mainly sulfated on oligosaccharide residues. Binds calcium with a low-affinity. Belongs to the chromogranin/secretogranin protein family.