164 research outputs found
Accuracy of SUPREX (stability of unpurified proteins from rates of H/D exchange) and MALDI mass spectrometry-derived protein unfolding free energies determined under non-EX2 exchange conditions
Protein conformations can be probed in top-down HDX MS experiments utilizing electron transfer dissociation of protein ions without hydrogen scrambling
Discrimination among IgG1-κ monoclonal antibodies produced by two cell lines using charge state distributions in nanoESI-TOF mass spectra
Using metal-catalyzed oxidation reactions and mass spectrometry to identify amino acid residues within 10 Ã… of the metal in Cu-binding proteins
Modifying the charge state distribution of proteins in electrospray ionization mass spectrometry by chemical derivatization
Electron capture dissociation distinguishes a single D-amino acid in a protein and probes the tertiary structure
Oxidative protein labeling in mass-spectrometry-based proteomics
Oxidation of proteins and peptides is a common phenomenon, and can be employed as a labeling technique for mass-spectrometry-based proteomics. Nonspecific oxidative labeling methods can modify almost any amino acid residue in a protein or only surface-exposed regions. Specific agents may label reactive functional groups in amino acids, primarily cysteine, methionine, tyrosine, and tryptophan. Nonspecific radical intermediates (reactive oxygen, nitrogen, or halogen species) can be produced by chemical, photochemical, electrochemical, or enzymatic methods. More targeted oxidation can be achieved by chemical reagents but also by direct electrochemical oxidation, which opens the way to instrumental labeling methods. Oxidative labeling of amino acids in the context of liquid chromatography(LC)–mass spectrometry (MS) based proteomics allows for differential LC separation, improved MS ionization, and label-specific fragmentation and detection. Oxidation of proteins can create new reactive groups which are useful for secondary, more conventional derivatization reactions with, e.g., fluorescent labels. This review summarizes reactions of oxidizing agents with peptides and proteins, the corresponding methodologies and instrumentation, and the major, innovative applications of oxidative protein labeling described in selected literature from the last decade
Irreversible thermal denaturation of cytochrome c studied by electrospray mass spectrometry
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