Human CHGA Recombinant Protein (His tag)

Background: Chromogranin A (CgA), also known as pituitary secretory protein I (SP-I), is a member of the granin family of regulated secretory proteins. CgA shares several protein characteristics common to the granin family: acidic isoelectric point, the capacity to bind calcium ions, the ability to form aggregates and multiple dibasic cleavage sites. Mature human CgA is 439 amino acids (aa) and contains 10 dibasic, proteolytic cleavage sites, capable of yielding several smaller peptides, each displaying a unique function. Mature human CgA shares 63% aa sequence identity with mouse and rat CgA. CgA is expressed exclusively in the secretory dense core granules of most normal and neoplastic neuroendocrine cells. Increased levels of CgA have been detected inpatients with neuroendocrine tumors as well as non-neuroendocrine tumors, hence CgA is an important serological marker for tumor diagnosis and monitoring tumorprogression/regression. It has been demonstrated in mouse model that full-length CgA containing its C-terminal region can impair angiogenesis and tumor growth. In addition, CgA can bind to Secretogranin III to regulate the biogenesis of secretory granules.