Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA 90095, USA.
Analyst. 2010 Apr;135(4):767-72. doi: 10.1039/b923303b.
An electrospray-assisted laser desorption/ionization source with an infrared OPO laser (IR-ELDI) was constructed and optimized for peptide and protein mass spectrometry analysis. Similar to ELDI with an ultraviolet laser, IR-ELDI generates multiply charged molecules for peptides and proteins measured under ambient sampling conditions. Both samples in the dried state and analyte solutions can be directly measured by IR-ELDI without the presence of a conventional MALDI matrix. However, the analysis of sample solutions is shown to greatly enhance the sensitivity of the mass spectrometry measurement, as a 100-fold sensitivity gain for peptide measurements was measured. The limit of detection of IR-ELDI was determined to be 250 fmol for bradykinin (1.1 kDa), 100 fmol for ubiquitin (8.6 kDa), and 500 fmol for carbonic anhydrase (29 kDa). IR-ELDI is amenable for MS and MSn analysis for proteins up to 80 kDa transferrin. IR-ELDI-MS may be a useful tool for protein sequencing analysis from complex biological matrices, with minimal sample preparation required.
构建并优化了一种基于红外光参量振荡器（IR-OPO）激光的电喷雾辅助激光解吸/电离源，用于肽和蛋白质的质谱分析。与紫外激光的 ELDI 类似，IR-ELDI 在环境采样条件下可产生用于测量肽和蛋白质的多电荷分子。无需传统的 MALDI 基质，IR-ELDI 可直接测量干燥状态的样品和分析物溶液。然而，对样品溶液的分析表明，这极大地提高了质谱测量的灵敏度，因为测量到肽的灵敏度提高了 100 倍。IR-ELDI 的检测限为：缓激肽（1.1 kDa）为 250 fmol，泛素（8.6 kDa）为 100 fmol，碳酸酐酶（29 kDa）为 500 fmol。IR-ELDI 适用于 MS 和 MSn 分析，可分析高达 80 kDa 的转铁蛋白。IR-ELDI-MS 可能是从复杂生物基质中进行蛋白质测序分析的有用工具，所需的样品制备最少。
