119th General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation of Young Analytical Chemists Ⅱ
Room No. 303호
Time FRI 10:02-:
Code ANAL2.O-28
Subject mPE-MMR to increase sensitivity and accuracy in peptide identifications from co-fragmented tandem mass spectra
Authors Madar Inamul Hasan, 이상원*
고려대학교 화학과, Korea
Abstract Mass spectrometry (MS)-based proteomics, which uses high-resolution hybrid mass spectrometers such as the quadrupole-orbitrap mass spectrometer, can yield tens of thousands of tandem mass (MS/MS) spectra of high resolution during a routine shotgun proteomics experiment. Despite being a fundamental step in MS-based proteomics, the accurate determination and assignment of precursor monoisotopic masses to the MS/MS spectra remains difficult. The difficulties stem from imperfect isotopic envelopes of precursor ions, inaccurate charge states for precursor ions, and co-fragmentation of MS/MS spectra. Here, we describe a composite method of utilizing MS data to efficiently assign accurate monoisotopic masses to MS/MS spectra, including those subject to co-fragmentation and unassigned charge state. The method, “multiplexed post-experiment monoisotopic mass refinement” (mPE-MMR), consists of the following: multiplexing of precursor masses to assign multiple monoisotopic masses of co-fragmented peptides to the corresponding multiplexed MS/MS spectra, multiplexing of charge states to assign correct charges to the precursor ions of MS/MS spectra with no charge information, and mass correction for inaccurate monoisotopic peak picking. When combined with MS-GF+, a database search algorithm based on fragment mass difference, mPE-MMR effectively increases both sensitivity and accuracy in PSMs and peptide identification from complex high-throughput proteomics data compared to conventional methods.
E-mail inambioinfo@gmail.com