Stemmler E A, Hettich R L, Hurst G B, Buchanan M V
Department of Chemistry, Bowdoin College, Brunswick, ME 04011.
Rapid Commun Mass Spectrom. 1993 Sep;7(9):828-36. doi: 10.1002/rcm.1290070910.
Conditions for the matrix-assisted laser desorption/ionization (MALDI) of oligodeoxyribonucleotides at 355 nm, developed using a 3-Tesla Fourier-transform ion cyclotron resonance mass spectrometer (FTMS), are reported. Efficient ion trapping and matrix selection are critical to the desorption and detection of oligonucleotides by FTMS. The achievable upper mass limit for the MALDI-FTMS of biomolecules on our 3-Tesla system has been extended from approximately 2 kDa to 6 kDa through the use of pulsed-trapping-plate ion deceleration techniques. By implementing the deceleration techniques, molecular ions for bovine insulin (MW = 5733.5), an oligodeoxythymidylic acid, pd[T]10 (MW = 3060.0), and a mixed-base 12-mer (MW = 3611.5) have been measured. For the analysis of oligonucleotides by FTMS, selection of an appropriate MALDI matrix is essential for the generation of [M-H]- ions. 3-Hydroxypicolinic acid provides a significant improvement over 2,5-dihydroxybenzoic acid for production of deprotonated molecules particularly for mixed-base oligomers. MALDI studies using FTMS have been duplicated using a newly constructed time-of-flight mass spectrometer (TOFMS) and oligonucleotide fragmentation on the TOFMS is reduced relative to that observed by FTMS. This may be a consequence of the longer times (milliseconds) required for FTMS detection.
报道了使用3特斯拉傅里叶变换离子回旋共振质谱仪（FTMS）在355nm波长下对寡脱氧核糖核苷酸进行基质辅助激光解吸/电离（MALDI）的条件。高效的离子捕获和基质选择对于FTMS对寡核苷酸的解吸和检测至关重要。通过使用脉冲捕获板离子减速技术，我们3特斯拉系统上生物分子的MALDI-FTMS可实现的质量上限已从约2 kDa扩展到6 kDa。通过实施减速技术，已测量了牛胰岛素（MW = 5733.5）、寡聚脱氧胸苷酸pd[T]10（MW = 3060.0）和混合碱基12聚体（MW = 3611.5）的分子离子。对于通过FTMS分析寡核苷酸，选择合适的MALDI基质对于生成[M-H]-离子至关重要。3-羟基吡啶甲酸比2,5-二羟基苯甲酸在生成去质子化分子方面有显著改进，特别是对于混合碱基寡聚物。使用新构建的飞行时间质谱仪（TOFMS）重复了使用FTMS的MALDI研究，并且TOFMS上的寡核苷酸碎片化相对于FTMS观察到的有所减少。这可能是FTMS检测所需时间较长（毫秒）的结果。
