Mass spectrometric analysis of biomarkers from actinomycetes
Chih-Chia Hsu1,2, Ming F. Tam2, Chau-Chung Han 3, T. H. Hsue1
1Department of Life science, National Tsing Hua University, HsinChu 300, Taiwan, ROC
2Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan, ROC
3Institute of Atomic and molecular sciences, Academia Sinica, Taipei 11529, Taiwan, ROC
Intact actinomycetes and their cellular extracts were analyzed directly on a matrix-assisted laser desorption/ionization time-of-flight（MALDI-TOF）mass spectrometer. Experiments were designed to identify biomarkers from different genera of actinomycetes. A biomarker of 7026 ± 2 Da was detected in the mass spectra of three species that belong to the genus Microbispora. Two other polypeptides of 5667 ± 1 and 7222 ± 1 Da were identified in two species of actinomycetes from the genus Dactylosporangium. After chromatography separation, the biomarker from Microbispora was subjected to protease digestion and ‘peptide mapping’ analysis. The results were used in database search. Furthermore, partial sequencing data were obtained by conventional Edman degradation and analyses of post source decay (PSD) and collision induced dissociation (CID) fragment ion spectra. From these analyses, we suggest the biomarker from Microbispora is a homolog of cold shock protein and mass spectrometry can provide a sensitive and accurate method for identifying microorganisms.