用于 MALDI-MS 分析中肽的一步式富集和脱盐的超疏水 candle soot/PDMS 基底。

Superhydrophobic candle soot/PDMS substrate for one-step enrichment and desalting of peptides in MALDI MS analysis.

机构信息

State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, PR China.

出版信息

Talanta. 2018 Dec 1;190:23-29. doi: 10.1016/j.talanta.2018.07.066. Epub 2018 Jul 21.

DOI:10.1016/j.talanta.2018.07.066

PMID:30172504

Abstract

Superhydrophobic substrate is applied in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) detection due to its confinement effect. The weak interaction of superhydrophobic surface with water/salts makes it potential in one-step enrichment and desalting of peptide in MALDI MS analysis. We fabricate a superhydrophobic substrate by spin-coating poly(dimethyl siloxane) (PDMS) on a candle soot layer. On this substrate, the peptide analytes can be confined and enriched in a small area due to the confinement effect and its strong hydrophobic interactions with PDMS. Meanwhile, the desalting can be easily realized by removing the residual solution after the absorption of analyst molecules due to the weak interaction between water/salt contaminants and the superhydrophobic surface. Using this substrate, angiotensin III (Ang III) in the presence of salt with high concentration (2 M or saturated) can be analyzed, and the peptide sequence coverage of 10 μg/mL myoglobin (MYO) and bovine serum albumin (BSA) digests is enhanced to 51% and 26%, which is 37% and 21% analyzed with the commercial ZipTipC pipette tips. The LOD of bacitracin A (Bac A) in milk with this substrate is 100 pM and nearly 360 times lower than the LOD of standard testing method. This substrate has potential practical applications in proteomics research and actual sample analysis.

摘要

超疏水基底因其限制效应而被应用于基质辅助激光解吸/电离质谱（MALDI MS）检测中。超疏水表面与水/盐的弱相互作用使其在 MALDI MS 分析中具有一步式富集和脱盐肽的潜力。我们通过在烛煤层上旋涂聚二甲基硅氧烷（PDMS）来制造超疏水基底。在这个基底上，由于限制效应和 PDMS 与其之间的强疏水相互作用，肽分析物可以被限制和富集在一个小区域内。同时，由于水/盐污染物与超疏水表面之间的弱相互作用，在吸收分析物分子后，很容易去除残留溶液，从而实现脱盐。使用这个基底，即使在高浓度（2 M 或饱和）盐存在的情况下，也可以分析血管紧张素 III（Ang III），并且 10 μg/mL 肌红蛋白（MYO）和牛血清白蛋白（BSA）消化物的肽序列覆盖率分别提高到 51%和 26%，而使用商业的 ZipTipC 吸液管 tips 进行分析时，分别为 37%和 21%。用这种基底在牛奶中检测杆菌肽 A（Bac A）的 LOD 为 100 pM，比标准检测方法的 LOD 低近 360 倍。该基底在蛋白质组学研究和实际样品分析中具有潜在的实际应用价值。