Work

An Improved Measurement of Isotopic Ratios by High Resolution Mass Spectrometry

Year: 2013

Type: article

Abstract: The study of protein kinetics requires an accurate measurement of isotopic ratios of peptides. Although Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometers yield accurate mass measurements of analytes, the isotopologue ratios are consistently lower than predicted. Recently, we demonstrated that the magnitude of the spectral error in the FT-ICR mass spectrometer is proportional to the scan duration of ions. Here, we present a novel isotopic ratio extrapolation (IRE) method for obtaining accurate isotopic ratio measurements. Accuracy is achieved by performing scans with different duration and extrapolation of the data to the initial moment of the ion rotation; IRE minimizes the absolute isotopic ratio error to ≤1%. We demonstrate the application of IRE in protein turnover studies using (2)H(2)O-metabolic labeling. Overall, this technique allows accurate measurements of the isotopic ratios of proteolytic peptides, a critical step for enabling routine studies of proteome dynamics.

Source: Journal of the American Society for Mass Spectrometry

DOI: 10.1007/s13361-012-0536-2

Authors: Serguei Ilchenko, Stephen F. Previs, Nadia Rachdaoui, Belinda Willard, Arthur J. McCullough, Takhar Kasumov

Institutions: Case Western Reserve University, Merck & Co., Inc., Rahway, NJ, USA (United States), Cleveland Clinic

Language: English

Topic: Mass Spectrometry Techniques and Applications

Subfield: Spectroscopy

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funders: National Heart, Lung, and Blood Institute, National Center for Research Resources

Awards: Enabling studies of proteome dynamics, Mitochondrial Proteome Dynamics in Heart Failure Assessed with Heavy Water