Chromogranin B: isolation from pheochromocytoma, N-terminal sequence, tissue distribution and secretory vesicle processing.

Abstract

The chromogranins/secretogranins are a family of neuroendocrine vesicle secretory proteins. Immunohistology and immunoblotting have suggested that a major soluble protein in human chromaffin granules may be chromogranin B (CgB). We purified from pheochromocytoma chromaffin granules an SDS-PAGE 110-120 kDa protein whose N-terminal sequence matched that previously deduced from a human CgB cDNA. An antibody directed against a synthetic human CgB N-terminal region specifically recognized the CgB N-terminus, though not the chromogranin A (CgA) N-terminus or the CgB C-terminus on immunoblots. An antiserum directed against CgB's C-terminus also visualized CgB but not CgA. By immunoblotting, CgB was a quantitatively major protein in human pheochromocytoma chromaffin granules, but a relatively minor in normal bovine adrenal medullary chromaffin granules. In a variety of normal bovine neuroendocrine tissues, the relative abundance of CgB immunoreactivity on immunoblots was: adrenal medulla greater than anterior pituitary greater than pancreas greater than small intestine, hypothalamus. Immunoblotting of neuroendocrine tissues (or their hormone storage vesicle cores) with both anti N-terminal and anti C-terminal CgB antisera suggested bidirectional cleavage or processing of CgB; in the anterior pituitary, a unique 40 kDa C-terminal fragment was observed. Bidirectional CgB cleavage was also suggested on immunoblots of chromaffin tissue from three species (human, bovine, rat). C-terminal processing of CgB was also confirmed by amino acid sequencing of SDS-PAGE-separated, polyvinylidene difluoride membrane-immobilized CgB fragments from pheochromocytoma chromaffin granules. Whether such fragments possess biological activity remains to be investigated.

• Authors: B M Gill, J A Barbosa, T Q Dinh, S Garrod, D T O'Connor
• Journal: Regulatory peptides (Regul Pept) Vol. 33 Issue 2 Pg. 223-35 (Apr 25 1991) ISSN: 0167-0115 [Print] Netherlands
• PMID: 1882087 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• CHGB protein, human
• Chromogranin B
• Chromogranins
• Immune Sera
• chromogranin B, rat

Topics

• Adrenal Gland Neoplasms (chemistry, metabolism)
• Amino Acid Sequence
• Animals
• Cattle
• Chromaffin Granules (chemistry)
• Chromatography, High Pressure Liquid
• Chromogranin B
• Chromogranins (isolation & purification, metabolism)
• Electrophoresis, Polyacrylamide Gel
• Humans
• Immune Sera (metabolism)
• Immunoblotting
• Molecular Sequence Data
• Neurosecretory Systems (metabolism)
• Pheochromocytoma (chemistry, metabolism)
• Protein Processing, Post-Translational
• Rats
• Species Specificity
• Tissue Distribution