Improved isotopic abundance measurements for high resolution Fourier transform ion cyclotron resonance mass spectra via time-domain data extraction
Improved isotopic abundance measurements for high resolution Fourier transform ion cyclotron resonance mass spectra via time-domain data extraction
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DOI：
10.1016/s1044-0305(98)00047-6
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发表时间：
1998-08-01
影响因子：
3.2
通讯作者：
Smith, RD
中科院分区：
文献类型：
--
作者：
Bresson, JA;Anderson, GA;Smith, RD
傅立叶变换离子回旋共振质谱仪与电喷雾的温和电离相结合，可以同时进行高分辨率和准确的质量测量，对蛋白质、多肽和寡核苷酸的表征具有吸引力，包括用于指定碎片质量的多级质谱仪测量，以及对结构测量的更大信心。对回旋加速器在较长时间段(某些情况下为几分钟)运动的探测允许更高的分辨率和质量精确度。一般来说，信号持续时间被认为主要受背景压力的限制，离子-中性碰撞会导致回旋加速器运动的减少和退相，从而导致信号损失。然而，最近的理论工作表明，作为高性能测量的先决条件的离子云稳定性高度依赖于离子云产生的电场，从而产生扩展时域信号所需的最少数量的电荷或离子。报道了离子布居对离子云稳定性和信号持续时间的影响，以及随后对分辨率和测量的同位素丰度的影响。提取了牛胰岛素同位素峰的单独的时间域信号，以便比较每个离子云的阻尼率，并且测量的时间域幅度极大值与理论预测的胰岛素同位素丰度提供了更好的匹配。这些结果表明，质量非常相似但离子云群大小不同的离子的不同阻尼率可以对观测到的同位素模式产生显著影响。此外，通过校正针对不同离子群大小观察到的不同阻尼率的影响，可以产生更准确、更高分辨率的光谱。(C)1998年美国质谱学学会。
The simultaneous high resolution and accurate mass measurements possible with Fourier transform ion cyclotron resonance mass spectrometry coupled with the gentle ionization of electrospray hold attractions for protein, peptide, and oligonucleotide characterization, including multistage-mass spectrometry measurements for assignment of fragment masses and greater confidence in structural measurements. The detection of cyclotron motion over extended periods of time (in some cases for several minutes) allows higher resolution and mass accuracy. Generally, signal duration has been considered to be limited primarily by background pressure, with ion-neutral collisions leading to the reduction and dephasing of cyclotron motion, causing signal loss. However, recent theoretical work has shown that the ion cloud stability that is a prerequisite for high performance measurements is highly dependent on the electric field generated by the ion cloud, thus giving rise to a minimum number of charges or ions required for extended time-domain signals. The effects of ion population on ion cloud stability and signal duration, and the subsequent effects on resolution and measured isotopic abundances are reported. Individual time-domain signals for bovine insulin isotopic peaks were extracted to allow a comparison of the damping rates for each of these ion clouds and the measured time-domain amplitude maxima are shown to provide a better match with the theoretically predicted isotopic abundances for insulin. These results show that different damping rates of ions of very similar mass, but different ion cloud population sizes, can have dramatic effects on the observed isotopic patterns. Additionally, more accurate, high resolution spectra can be produced by correcting for the effects of the different damping rates that are observed for different ion population sizes. (C) 1998 American Society for Mass Spectrometry.