Biomarker analysis by mass spectrometry (MS) can allow for the rapid quantification of low abundant biomarkers. However, the complexity of human serum is a limiting factor in MS-based bioanalysis; therefore, novel biomarker enrichment strategies are of interest, particularly if the enrichment strategies are of low cost and are easy to use. One such strategy involves the use of molecularly imprinted polymers (MIPs) as synthetic receptors for biomarker enrichment. In the present study, a magnetic solid-phase extraction (mSPE) platform, based on magnetic MIP (mMIP) sorbents, is disclosed, for use in the MS-based quantification of proteins by the bottom-up approach. Progastrin releasing peptide (ProGRP), a low abundant and clinically sensitive biomarker for small cell lung cancer (SCLC), was used to exemplify the mSPE platform. Four different mMIPs were synthesized, and an mSPE method was developed and optimized for the extraction of low concentrations of tryptic peptides from human serum. The mSPE method enabled the selective extraction of the ProGRP signature peptide, the nonapeptide NLLGLIEAK, prior to quantification of the target via LC-MS/MS. Overall, the mSPE method demonstrated its potential as a low cost, rapid, and straightforward sample preparation method, with demonstrably strong binding, acceptable recoveries, and good compatibility with MS. mMIPs are a potential low-cost alternative to current clinical methods for biomarker analysis.

中文翻译：

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磁性合成受体，用于蛋白质生物标志物定量中的选择性清除。

通过质谱（MS）进行生物标记分析可以快速定量低丰度的生物标记。然而，人类血清的复杂性是基于MS的生物分析的限制因素。因此，新颖的生物标记物富集策略是令人感兴趣的，特别是如果该富集策略成本低并且易于使用。一种这样的策略涉及使用分子印迹聚合物（MIP）作为生物标记富集的合成受体。在本研究中，公开了一种基于磁性MIP（mMIP）吸附剂的磁性固相萃取（mSPE）平台，可用于自下而上方法基于MS的蛋白质定量。前胃泌素释放肽（ProGRP）是一种针对小细胞肺癌（SCLC）的低丰度且临床敏感的生物标志物，被用于例证mSPE平台。合成了四种不同的mMIP，并开发了mSPE方法并对其进行了优化，以从人血清中提取低浓度的胰蛋白酶肽。mSPE方法能够在通过LC-MS / MS定量目标之前，选择性提取ProGRP标志肽，即非肽NLLGLIEAK。总的来说，mSPE方法具有低成本，快速，简单的样品制备方法的潜力，具有很强的结合力，可接受的回收率以及与MS的良好兼容性。mMIPs是目前用于生物标志物分析的临床方法的潜在低成本替代品。通过LC-MS / MS对靶标进行定量之前，先使用九肽NLLGLIEAK。总的来说，mSPE方法具有低成本，快速，简单的样品制备方法的潜力，具有很强的结合力，可接受的回收率以及与MS的良好兼容性。mMIPs是目前用于生物标志物分析的临床方法的潜在低成本替代品。通过LC-MS / MS对靶标进行定量之前，先使用九肽NLLGLIEAK。总的来说，mSPE方法具有低成本，快速，简单的样品制备方法的潜力，具有很强的结合力，可接受的回收率以及与MS的良好兼容性。mMIPs是目前用于生物标志物分析的临床方法的潜在低成本替代品。