on 09-25-201306:52 AM - edited on 10-15-202106:22 AM by Closed Account
Shaw JB, Li W, Holden DD, Zhang Y, Griep-Raming J, Fellers RT, Early BP, Thomas PM, Kelleher NL, Brodbelt JS. J Am Chem Soc. 2013 Aug 28;135(34):12646-51. The top-down approach to proteomics offers compelling advantages due to the potential to provide complete characterization of protein sequence and post-translational modifications. Here we describe the implementation of 193 nm ultraviolet photodissociation (UVPD) in an Orbitrap mass spectrometer for characterization of intact proteins. Near-complete fragmentation of proteins up to 29 kDa is achieved with UVPD including the unambiguous localization of a single residue mutation and several protein modifications on Pin1 (Q13526), a protein implicated in the development of Alzheimer's disease and in cancer pathogenesis. The 5 ns, high-energy activation afforded by UVPD exhibits far less precursor ion-charge state dependence than conventional collision- and electron-based dissociation methods.