| Autor: |
Kafader JO; Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60208, United States., Durbin KR; Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60208, United States., Melani RD; Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60208, United States., Des Soye BJ; Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60208, United States., Schachner LF; Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60208, United States., Senko MW; Thermo Fisher Scientific, San Jose, California 95134, United States., Compton PD; Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60208, United States., Kelleher NL; Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60208, United States. |
| Abstrakt: |
Charge detection mass spectrometry (CDMS) is mainly utilized to determine the mass of intact molecules. Previous applications of CDMS have determined the mass-to-charge ratio and the charge of large polymers, DNA molecules, and native protein complexes, from which corresponding mass values could be assigned. Recent advances have demonstrated that CDMS using an Orbitrap mass analyzer yields the reliable assignment of integer charge states that enables individual ion mass spectrometry (I 2 MS) and spectral output directly into the mass domain. Here I 2 MS analysis was extended to isotopically resolved fragment ions from intact proteoforms for the first time. With a radically different bias for ion readout, I 2 MS identified low-abundance fragment ions containing many hundreds of residues that were undetectable by standard Orbitrap measurements, leading to a doubling in the sequence coverage of triosephosphate isomerase. Thus MS/MS with the detection of individual ions (MS/I 2 MS) provides a far greater ability to detect high mass fragment ions and exhibits strong complementarity to traditional spectral readout in this, its first application to top-down mass spectrometry. |
