title: Extracting biomolecule collision cross sections from the high-resolution FT-ICR mass spectral linewidths.
abstract: It is known that the ion collision cross section (CCS) may be calculated from the linewidth of a Fourier transform ion cyclotron resonance (FT-ICR) mass spectral peak at elevated pressure (e.g., ∼10(-6) Torr). However, the high mass resolution of FT-ICR is sacrificed in those experiments due to high buffer gas pressure. In this study, we describe a linewidth correction method to eliminate the windowing-induced peak broadening effect. Together with the energetic ion-neutral collision model previously developed by our group, this method enables the extraction of CCSs of biomolecules from high-resolution FT-ICR mass spectral linewidths, obtained at a typical operating buffer gas pressure of modern FT-ICR instruments (∼10(-10) Torr). CCS values of peptides including MRFA, angiotensin I, and bradykinin measured by the proposed method agree well with ion mobility measurements, and the unfolding of protein ions (ubiquitin) at higher charge states is also observed.
authors: School of Life Science, Beijing Institute of Technology, Haidian, Beijing 100081, China. weixu@bit.edu.cn.
authors: Ting
authors: T
authors: Jiang
authors: The Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors: Yu
authors: Y
authors: Chen
authors: School of Life Science, Beijing Institute of Technology, Haidian, Beijing 100081, China. weixu@bit.edu.cn.
authors: Lu
authors: L
authors: Mao
authors: Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA. marshall@magnet.fsu.edu and Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
authors: Alan G
authors: AG
authors: Marshall
authors: School of Life Science, Beijing Institute of Technology, Haidian, Beijing 100081, China. weixu@bit.edu.cn.
authors: Wei
authors: W
authors: Xu
mesh_terms: D000803:Angiotensin I / Q000737:chemistry*; D001920:Bradykinin / Q000737:chemistry*; D017357:Cyclotrons; D045304:Cytochromes c / Q000737:chemistry*; D005583:Fourier Analysis; D013058:Mass Spectrometry; D011312:Pressure; D025801:Ubiquitin / Q000737:chemistry*
chemical_list: D025801:Ubiquitin; D045304:Cytochromes c; D000803:Angiotensin I; D001920:Bradykinin