RESUMEN
A platform was developed to analyze MS/MS spectra from large peptides with low part-per-million mass accuracy, including a commercial-grade software suite. Termed Middle Down Proteomics, this platform identified 7454 peptides from 2-20 kDa (1472 unique) from 555 proteins after 23 LC-MS/MS injections of Lys-C digests of HeLa-S3 nuclear proteins. Along with greatly increased confidence for both peptide identification (expectation values from 10(-89) to 10(-4)) and characterization (up to 18% of peptides were modified in some LC-MS/MS runs), fragmentation data with <2 ppm accuracy enabled error tolerant and routine multiplexed database searching-all clearly demonstrated in this study.
Asunto(s)
Péptidos/química , Espectrometría de Masas en Tándem/métodos , Algoritmos , Secuencia de Aminoácidos , Bases de Datos de Proteínas , Células HeLa , Humanos , Espectrometría de Masas/métodos , Datos de Secuencia Molecular , Procesamiento Proteico-Postraduccional , Proteínas/análisis , Proteómica/métodos , Reproducibilidad de los Resultados , Programas InformáticosRESUMEN
ProSight PTM 2.0 (http://prosightptm2.scs.uiuc.edu) is the next generation of the ProSight PTM web-based system for the identification and characterization of proteins using top down tandem mass spectrometry. It introduces an entirely new data-driven interface, integrated Sequence Gazer for protein characterization, support for fixed modifications, terminal modifications and improved support for multiple precursor ions (multiplexing). Furthermore, it supports data import and export for local analysis and collaboration.
