Department of Chemistry, Texas A and M University, College Station, Texas 77843, USA.
J Am Soc Mass Spectrom. 2010 Sep;21(9):1612-9. doi: 10.1016/j.jasms.2010.04.010. Epub 2010 Apr 24.
The off-line coupling of an isoelectric trapping device termed membrane separated wells for isoelectric focusing and trapping (MSWIFT) to mass spectrometry-based proteomic studies is described. The MSWIFT is a high capacity, high-throughput, mass spectrometry-compatible isoelectric trapping device that provides isoelectric point (pI)-based separations of complex mixtures of peptides. In MSWIFT, separation and analyte trapping are achieved by migrating the peptide ions through membranes having fixed pH values until the peptide pI is bracketed by the pH values of adjacent membranes. The pH values of the membranes can be tuned, thus affording a high degree of experimental flexibility. Specific advantages of using MSWIFT for sample prefractionation include: (1) small sample volumes (approximately 200 microL), (2) customized membranes over a large pH range, (3) flexibility in the number of desired fractions, (4) membrane compatibility with a variety of solvents systems, and (5) resulting fractions do not require sample cleanup before MS analysis. Here, we demonstrate the utility of MSWIFT for mass spectrometry-based detection of peptides in improving dynamic range and the reduction of ion suppression effects for high-throughput separations of tryptic peptides.
本文描述了一种称为膜分离 Wells 用于等电聚焦和捕获（MSWIFT）的非在线耦合设备与基于质谱的蛋白质组学研究的联用。MSWIFT 是一种高通量、大容量、兼容质谱的等电捕获设备，可提供基于等电点（pI）的复杂肽混合物分离。在 MSWIFT 中，通过穿过具有固定 pH 值的膜来实现分离和分析物捕获，直到肽的 pI 被相邻膜的 pH 值包围。膜的 pH 值可以进行调整，从而提供了高度的实验灵活性。使用 MSWIFT 进行样品预分级的具体优点包括：（1）小样品体积（约 200 μL），（2）在较大 pH 范围内定制膜，（3）所需分数数量灵活，（4）膜与多种溶剂系统兼容，以及（5）所得分数在进行 MS 分析之前不需要进行样品净化。在这里，我们展示了 MSWIFT 在基于质谱的肽检测中的应用，以提高动态范围并减少高通量胰蛋白酶肽分离中的离子抑制效应。
