Mass spectrometry-based neuropeptidomics of secretory vesicles from human adrenal medullary pheochromocytoma reveals novel peptide products of prohormone processing.

Abstract

Neuropeptides are required for cell-cell communication in the regulation of physiological and pathological processes. While selected neuropeptides of known biological activities have been studied, global analyses of the endogenous profile of human peptide products derived from prohormones by proteolytic processing in vivo are largely unknown. Therefore, this study utilized the global, unbiased approach of mass spectrometry-based neuropeptidomics to define peptide profiles in secretory vesicles, isolated from human adrenal medullary pheochromocytoma of the sympathetic nervous system. The low molecular weight pool of secretory vesicle peptides was subjected to nano-LC-MS/MS with ion trap and QTOF mass spectrometry analyzed by different database search tools (InsPecT and Spectrum Mill). Peptides were generated by processing of prohormones at dibasic cleavage sites as well as at nonbasic residues. Significantly, peptide profiling provided novel insight into newly identified peptide products derived from proenkephalin, pro-NPY, proSAAS, CgA, CgB, and SCG2 prohormones. Previously unidentified intervening peptide domains of prohormones were observed, thus providing new knowledge of human neuropeptidomes generated from precursors. The global peptidomic approach of this study demonstrates the complexity of diverse neuropeptides present in human secretory vesicles for cell-cell communication.

• Authors: Nitin Gupta, Steven J Bark, Weiya D Lu, Laurent Taupenot, Daniel T O'Connor, Pavel Pevzner, Vivian Hook
• Journal: Journal of proteome research (J Proteome Res) Vol. 9 Issue 10 Pg. 5065-75 (Oct 01 2010) ISSN: 1535-3907 [Electronic] United States
• PMID: 20704348 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Enkephalins
• Neuropeptides
• Peptides
• Protein Precursors
• SCG2 protein, human
• Secretogranin II
• proenkephalin

Topics

• Adrenal Gland Neoplasms (metabolism, pathology)
• Adrenal Medulla (metabolism, pathology)
• Amino Acid Sequence
• Cell Communication
• Chromaffin Granules (metabolism)
• Chromatography, Liquid
• Enkephalins (metabolism)
• Humans
• Mass Spectrometry (methods)
• Molecular Sequence Data
• Neuropeptides (metabolism)
• Peptides (metabolism)
• Pheochromocytoma (metabolism, pathology)
• Protein Precursors (metabolism)
• Proteomics (methods)
• Secretogranin II (metabolism)
• Secretory Vesicles (metabolism)