Characterization of the ribosomal protein biomarkers of Actinobacteria via genomics and MALDI-TOF MS techniques

Abstract:

[Objective] Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) technique provides mass spectral fingerprints of characteristic proteins for microbial identification. This study aims to characterize the ribosomal protein biomarkers from Actinobacteria via genomics and MALDI-TOF MS techniques. [Methods] Actinobacteria representatives were chosen from MALDI-TOF MS spectral library. By searching against genome database, we acquired the ribosomal protein sequences from the target or reference strains of target species and calculated the theoretical molecular masses. The mass peaks in the MALDI-TOF mass spectra of target strains were annotated with the calculated molecular masses of ribosomal proteins. [Results] Mass peaks annotated in the spectra of 142 strains of 114 species, 53 genera, 24 families from 8 orders were assigned to 31 ribosomal proteins. The number of annotated ribosomal proteins varied significantly among strains. The number of mass peak annotations also varied considerably among different subunit proteins. A total of 15 ribosomal proteins were annotated in over half of the spectra, and the ribosomal protein with the most mass peak annotations was L36. [Conclusion] This study identified 15 common ribosomal protein mass peaks in MALDI-TOF mass spectra of Actinobacteria. The results can support the establishment of a method for the identification of Actinobacteria by matching characteristic mass peaks of ribosomal protein biomarkers in MALDI-TOF mass spectra.