Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States.
Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27659, United States.
J Am Soc Mass Spectrom. 2022 Jun 1;33(6):1031-1037. doi: 10.1021/jasms.2c00087. Epub 2022 May 19.
Native mass spectrometry (MS) and charge detection-mass spectrometry (CD-MS) have become versatile tools for characterizing a wide range of proteins and macromolecular complexes. Both commonly use nanoelectrospray ionization (nESI) from pulled borosilicate needles, but some analytes are known to nonspecifically adsorb to the glass, which may lower sensitivity and limit the quality of the data. To improve the sensitivity of native MS and CD-MS, we modified the surface of nESI needles with inert surface modifiers, including polyethylene-glycol. We found that the surface modification improved the signal intensity for native MS of proteins and for CD-MS of adeno-associated viral capsids. Based on mechanistic comparisons, we hypothesize that the improvement is more likely due to an increased flow rate with coated ESI needles rather than less nonspecific adsorption. In any case, these surface-modified needles provide a simple and inexpensive method for improving the sensitivity of challenging analytes.
原位质谱（MS）和电荷检测质谱（CD-MS）已成为广泛用于表征各种蛋白质和大分子复合物的多功能工具。这两种方法通常都使用从拉制的硼硅酸盐针中进行的纳升电喷雾（nESI），但已知某些分析物会非特异性地吸附到玻璃上，这可能会降低灵敏度并限制数据的质量。为了提高原位 MS 和 CD-MS 的灵敏度，我们用惰性表面修饰剂（包括聚乙二醇）修饰了 nESI 针的表面。我们发现，表面修饰提高了蛋白质的原位 MS 和腺相关病毒衣壳的 CD-MS 的信号强度。基于机理比较，我们假设这种改进更可能是由于涂覆的 ESI 针的流速增加，而不是非特异性吸附减少。无论如何，这些表面修饰的针提供了一种简单且廉价的方法，可用于提高具有挑战性的分析物的灵敏度。
