Poster Presentation HUPO 2019 - 18th Human Proteome Organization World Congress

Data-independent acquisition mass spectrometry(DIA-MS) accompanied with precursor mass assignment enhances peptide identification (#499)

Nam Dowoon 1 , Mun Dong-Gi 1 , Kim Hokeun 1 , Pandey Akhilesh 2 , Sang-Won Lee 1
  1. Korea University, Seongbukgu, SEOUL, South Korea
  2. Department of Laboratory Medicine and Pathology, Mayo Clinic, MN

Data-independent acquisition (DIA) has become promising strategy for both comprehensive identification and accurate quantification due to advanced mass spectrometers and up-to-date data analysis techniques. However, DIA produces highly complex multiplexed tandem MS spectra which makes it difficult to interpret. In order to facilitate robust and large-scale quantification along with exhaustive protein identification, different strategy for analyzing DIA data has to be developed. Here, we present a novel strategy based on unambiguous precursor mass assignment through the mPE-MMR (multiplexed post-experimental monoisotopic mass refinement) procedure combining with complementary multi-stage database searching. Accurate monoisotopic masses of multiple precursor ions are determined by mPE-MMR and resulting data were processed with multi-stage search involving Spectral library search (SLS), MS-GF+ and MODa/MODi. Precise precursor mass assignment prior to SLS resulted more sensitive and accurate peptide identification compared to conventional SLS. Moreover, assignment of precursor mass data to DIA tandem MS data allowed spectrum-centric database search engines, MS-GF+ and MODa/MODi, to applied and identified sample-specific mutated peptides and post-translational-modified peptides. This novel strategy shows considerable potential for interpreting DIA data and further exploited by adopting methods that support to obtain high-dynamic range of MS data.