| Abstract
| - Characteristic ions in the MALDI TOF mass spectra frombacterial cells have been associated with four knownproteins. The proteins, observed both from cells and infiltered cellular suspensions, were isolated by HPLC andidentified on the basis of their mass spectra and theirpartial amino acid sequence, determined using theEdman method (10−15 residues). The acid resistanceproteins HdeA and HdeB give rise to ions near m/z 9735and 9060 in MALDI TOF mass spectra from cells andfrom extracts of both Escherichiacoli 1090 andShigellaflexneri PHS-1059. However, the proteinsassociated with proteolytic cleavage by the peptidase Lep,rather than the precursor proteins, were observed, bothusing cells and from cellular extracts. A cold-shockprotein, CspA, was associated with the ion near m/z 7643from Pseudomonasaeruginosa. Similarly, a cold-acclimation protein, CapB, was identified as the source ofthe ion near m/z 7684 in P. putida. This last proteinwas homologous with a known CapB from P. fragi. Whilethese experiments involved the detection of known orhomologous proteins from typical bacteria, this sameapproach could also be applied to the detection of uniqueproteins or biomarker proteins associated with otherbacteria of public health significance.
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