Bioinformatics Graduate Program, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA.
J Proteome Res. 2010 Oct 1;9(10):5065-75. doi: 10.1021/pr100358b.
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.
神经肽是细胞间通讯所必需的，在生理和病理过程的调节中起着重要作用。虽然已经研究了具有已知生物学活性的选定神经肽，但对体内蛋白水解加工产生的人类前激素来源的内源性肽产物的内源性谱进行全面分析在很大程度上仍是未知的。因此，本研究利用基于质谱的神经肽组学的全局、无偏方法，来定义源自人交感神经肾上腺髓质嗜铬细胞瘤的分泌小泡中的肽谱。将分泌小泡中低分子量的肽池进行纳升液相色谱-串联质谱分析，采用离子阱和 QTOF 质谱分析不同数据库搜索工具（InsPecT 和 Spectrum Mill）进行分析。肽是通过双碱性切割位点以及非碱性残基对前激素进行加工而产生的。值得注意的是，肽谱分析为源自前脑啡肽原、前神经肽 Y 原、前 SAAS 原、CgA、CgB 和 SCG2 前激素的新鉴定的肽产物提供了新的见解。观察到前激素中以前未识别的中间肽结构域，从而为源自前体的人类神经肽组提供了新知识。本研究的全局肽组学方法展示了存在于人分泌小泡中用于细胞间通讯的各种神经肽的复杂性。
