Li K W, Hoek R M, Smith F, Jiménez C R, van der Schors R C, van Veelen P A, Chen S, van der Greef J, Parish D C, Benjamin P R
Graduate School Neurosciences Amsterdam, Research Institute Neurosciences Vrije Universiteit, Faculty of Biology, The Netherlands.
J Biol Chem. 1994 Dec 2;269(48):30288-92.
A novel strategy combining peptide fingerprinting of single neurons by matrix-assisted laser desorption ionization mass spectrometry, molecular cloning, peptide chemistry, and electrospray ionization mass spectrometry was used to study the intricate processing pattern of a preprohormone expressed in identified neurons, the neuroendocrine light yellow cells (LYCs) of the gastropod mollusc, Lymnaea stagnalis. The cDNA encoding the precursor, named prepro-LYCP (LYCPs, light yellow cell peptides), predicts a straightforward processing into three peptides, LYCP I, II, and III, at conventional dibasic processing sites flanking the peptide domains on the precursor. However, matrix-assisted laser desorption ionization mass spectrometry of single LYCs revealed trimmed variant peptides derived from LYCP I and II. The variants were much more abundant than the intact peptides, indicating that LYCP I and II serve as intermediates in a peptide-processing sequence. Using the molecular masses of the peptides as markers to guide their isolation by well established purification methods, the structural identities of the peptides could be confirmed by amino acid sequencing. Furthermore, matrix-assisted laser desorption ionization mass spectrometry could detect colocalization of a novel peptide with the LYCPs.
一种结合了通过基质辅助激光解吸电离质谱对单个神经元进行肽指纹分析、分子克隆、肽化学和电喷雾电离质谱的新策略，被用于研究在已鉴定神经元（腹足纲软体动物椎实螺的神经内分泌浅黄细胞，LYCs）中表达的一种前激素原的复杂加工模式。编码该前体的cDNA，命名为前体-LYCP（LYCPs，浅黄细胞肽），预测在前体上肽结构域两侧的常规双碱性加工位点会直接加工成三种肽，即LYCP I、II和III。然而，单个LYC的基质辅助激光解吸电离质谱显示了源自LYCP I和II的经修剪的变体肽。这些变体比完整肽丰富得多，表明LYCP I和II在肽加工序列中作为中间体。利用肽的分子量作为标记，通过成熟的纯化方法指导其分离，肽的结构同一性可通过氨基酸测序得到确认。此外，基质辅助激光解吸电离质谱可以检测到一种新肽与LYCPs的共定位。
