Collagen remodeling in normal and pathologic conditions releases numerous collagen fragments into biological fluids. Although a few collagen fragments have been tested as biomarkers for disease indication, most occur at trace levels, making them nearly impossible to detect even with modern analytical tools. Here we report a new way to enrich collagen fragments that allows complete peptidomic analysis of collagen fragments in urine. Enrichment is made possible by dimeric collagen hybridizing peptides (CHPs) that bind collagen fragments originating from the triple helical regions of all collagen types with minimal sequence bias. LC-MS/MS analysis of enriched mouse urine revealed an average of 383 collagenous peptide fragments per sample (compared to 34 for unenriched sample), which could be mapped to all types of mouse collagens in the SwissProt database including FACITs and MACITs. Hierarchical clustering of a selected panel of the detected fragments separated osteopenic mice from healthy mice. The results demonstrate dimeric CHP’s ability to enrich collagen fragments from biological fluid and its potential to aid peptidomics-based disease detection and biomarker discovery.

中文翻译：

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使用二聚体胶原蛋白杂交肽进行尿胶原蛋白富集胶原蛋白片段。

在正常和病理条件下的胶原蛋白重塑将大量胶原蛋白片段释放到生物体液中。尽管已经测试了一些胶原蛋白片段作为疾病指示的生物标志物，但是大多数胶原蛋白片段都以痕量水平存在，即使使用现代分析工具也几乎无法检测到它们。在这里，我们报告了一种富集胶原蛋白片段的新方法，该方法可以对尿液中的胶原蛋白片段进行完整的肽组分析。通过二聚体胶原蛋白杂交肽（CHP）富集成为可能，该多肽以最小的序列偏差结合源自所有胶原蛋白类型的三螺旋区的胶原蛋白片段。对富集的小鼠尿液进行的LC-MS / MS分析显示，每个样品平均含有383个胶原蛋白肽片段（未富集的样品为34个），可以将其映射到SwissProt数据库中的所有类型的小鼠胶原蛋白，包括FACIT和MACIT。选择的检测片段组的分层聚类将骨质疏松小鼠与健康小鼠分开。结果表明，二聚体CHP能够从生物体液中富集胶原蛋白片段，并且具有辅助基于肽组学的疾病检测和生物标记物发现的潜力。