Yang Xiaomin, Hu Lianghai, Ye Mingliang, Zou Hanfa
College of Chemistry, Jilin University, Changchun 130012, China.
Key Laboratory Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China; Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
Anal Chim Acta. 2014 Jun 4;829:40-7. doi: 10.1016/j.aca.2014.04.040. Epub 2014 Apr 26.
Peptides in urine are excreted by kidney from the blood and tissues, which are composed of a large amount of hormones, cytokines, regulatory factors and the metabolized fragments of proteins. The peptide distribution in urine will reflect the physiological and pathophysiological processes in body. In past, limited information was reported about the composition of the peptides in urine. One possible reason is that the peptides in urine are fairly low abundant and there are high concentrations of salts and organic metabolites in the urine. In this report, we extracted the peptides from human urine by highly ordered mesoporous silica particles with the pore size of 2 nm, which will exclude the high molecular weight proteins over 12 kDa. The extracted peptides were then separated into fractions according to their molecular weight by size exclusion chromatography. Each of the fractions was further analyzed by MALDI-TOF MS and μRPLC-MS/MS. Totally, 193 peptides were identified by two-dimensional SEC/μRPLC-MS/MS analysis. By analyzing the progenitor protein of the peptides; we found that two-thirds of the proteins differed from the reported urine proteome database, and the high abundant proteins in urine proteome were less detected in the urine peptidome. The developed extraction and separation methods were efficient for the profiling of the endogenous peptides in human urine. The peptidome in human urine was complementary to the human urinary proteome and may provide an emerging field for biomarker discovery.
尿液中的肽由肾脏从血液和组织中排泄而来，它们由大量激素、细胞因子、调节因子以及蛋白质的代谢片段组成。尿液中的肽分布将反映体内的生理和病理生理过程。过去，关于尿液中肽的组成报道的信息有限。一个可能的原因是尿液中的肽丰度相当低，且尿液中盐和有机代谢物的浓度很高。在本报告中，我们用孔径为2nm的高度有序介孔二氧化硅颗粒从人尿中提取肽，该颗粒将排除分子量超过12kDa的高分子量蛋白质。然后通过尺寸排阻色谱法根据分子量将提取的肽分离成不同组分。每个组分再通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）和纳升反相液相色谱-串联质谱（μRPLC-MS/MS）进一步分析。通过二维尺寸排阻色谱/纳升反相液相色谱-串联质谱分析，共鉴定出193种肽。通过分析肽的前体蛋白，我们发现三分之二的蛋白与已报道的尿蛋白质组数据库不同，且尿蛋白质组中的高丰度蛋白在尿肽组中较少被检测到。所开发的提取和分离方法对于分析人尿中的内源性肽是有效的。人尿中的肽组与人类尿液蛋白质组互补，可能为生物标志物的发现提供一个新领域。
