Damon Griffiths, Juan P Rincon Pabon, Charlotte Guffick, Argyris Politis
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引用次数: 0
Abstract
Hydrogen/deuterium exchange mass spectrometry (HDX-MS) is a powerful technique for studying protein structural dynamics. A critical step in the HDX-MS workflow is generating a peptide map from nondeuterated samples, which serves as the reference for identifying and monitoring peptides in subsequent deuterium-labeled experiments. Maximizing peptide identifications improves sequence coverage and redundancy, enhancing the information content and spatial resolution of the HDX-MS data. However, peptide identification is often limited by suboptimal peptide separation/fragmentation. In other proteomic workflows, longer liquid chromatography (LC) gradients are commonly used to improve the peptide identification by increasing resolution. However, in HDX-MS workflows, such gradients are generally incompatible due to time constraints imposed by deuterium/hydrogen back-exchange. To address this, we introduce a flexible workflow that uses long-gradients during initial peptide mapping, followed by retention time (RT) interpolation for application in subsequent short-gradient HDX-MS. By performing both long- and short-gradient peptide mapping, we used shared peptides to generate a regression model that predicts short-gradient RTs for all peptides identified in the long-gradient experiment. This enables the use of the richer peptide maps provided by long-gradient chromatography without compromising the deuterium retention. The method is implemented by RTinterpolator, a freely available R script compatible with widely used HDX analysis platforms that rely on reference RT values for peptide monitoring in deuterium-labeled data. By providing predicted RTs aligned to short gradients, RTinterpolator offers a practical, accessible, and instrument-independent way of increasing sequence coverage and redundancy in HDX-MS experiments, particularly for large or complex proteins susceptible to the limitations of short-gradient chromatography.
期刊介绍:
The Journal of the American Society for Mass Spectrometry presents research papers covering all aspects of mass spectrometry, incorporating coverage of fields of scientific inquiry in which mass spectrometry can play a role.
Comprehensive in scope, the journal publishes papers on both fundamentals and applications of mass spectrometry. Fundamental subjects include instrumentation principles, design, and demonstration, structures and chemical properties of gas-phase ions, studies of thermodynamic properties, ion spectroscopy, chemical kinetics, mechanisms of ionization, theories of ion fragmentation, cluster ions, and potential energy surfaces. In addition to full papers, the journal offers Communications, Application Notes, and Accounts and Perspectives