Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005, USA.
J Am Soc Mass Spectrom. 2010 Apr;21(4):550-8. doi: 10.1016/j.jasms.2009.12.016. Epub 2010 Jan 4.
Mass analysis of proteolytic fragment peptides following hydrogen/deuterium exchange offers a general measure of solvent accessibility/hydrogen bonding (and thus conformation) of solution-phase proteins and their complexes. The primary problem in such mass analyses is reliable and rapid assignment of mass spectral peaks to the correct charge state and degree of deuteration of each fragment peptide, in the presence of substantial overlap between isotopic distributions of target peptides, autolysis products, and other interferant species. Here, we show that at sufficiently high mass resolving power (m/Delta m(50%) > or = 100,000), it becomes possible to resolve enough of those overlaps so that automated data reduction becomes possible, based on the actual elemental composition of each peptide without the need to deconvolve isotopic distributions. We demonstrate automated, rapid, reliable assignment of peptide masses from H/D exchange experiments, based on electrospray ionization FT-ICR mass spectra from H/D exchange of solution-phase myoglobin. Combined with previously demonstrated automated data acquisition for such experiments, the present data reduction algorithm enhances automation (and thus expands generality and applicability) for high-resolution mass spectrometry-based analysis of H/D exchange of solution-phase proteins.
肽的酶解片段经氢/氘交换后的质量分析可提供溶液相蛋白质及其复合物的溶剂可及性/氢键（以及因此构象）的一般测量方法。在目标肽、自解产物和其他干扰物质的同位素分布有很大重叠的情况下，这种质量分析的主要问题是可靠和快速地将质谱峰分配给每个片段肽的正确电荷状态和氘化程度。在这里，我们表明，在足够高的质量分辨率（m/Delta m(50%)>或=100,000）下，有可能解析足够多的重叠，从而可以在无需解卷积同位素分布的情况下，基于每个肽的实际元素组成实现自动化数据减少。我们展示了基于溶液相肌红蛋白的 H/D 交换的电喷雾电离 FT-ICR 质谱，实现了从 H/D 交换实验中自动、快速、可靠地分配肽质量。与之前证明的此类实验的自动数据采集相结合，本数据减少算法增强了基于高分辨率质谱的溶液相蛋白质 H/D 交换分析的自动化（从而扩展了通用性和适用性）。
