Identification of Pseudomonas aeruginosa exopolysaccharide Psl in biofilms using 3D OrbiSIMS
Volume
18
Publisher
DOI
10.1116/6.0002604
Journal
Biointerphases
Issue
ISSN
1934-8630
Metadata
Show full item recordAbstract
Secondary ion mass spectrometry (SIMS) offers advantages over both liquid extraction mass spectrometry and matrix assisted laser desorption mass spectrometry in that it provides the direct in situ analysis of molecules and has the potential to preserve the 3D location of an
analyte in a sample. Polysaccharides are recognized as challenging analytes in the mass spectrometry of liquids and are also difficult to identify and assign using SIMS. Psl is an exopolysaccharide produced by Pseudomonas aeruginosa, which plays a key role in biofilm formation
and maturation. In this Letter, we describe the use of the OrbiTrap analyzer with SIMS (3D OrbiSIMS) for the label-free mass spectrometry
of Psl, taking advantage of its high mass resolving power for accurate secondary ion assignment. We study a P. aeruginosa biofilm and
compare it with purified Psl to enable the assignment of secondary ions specific to the Psl structure. This resulted in the identification of 17
peaks that could confidently be ascribed to Psl fragments within the biofilm matrix. The complementary approach of the following neutral
loss sequences is also shown to identify multiple oligosaccharide fragments without the requirement of a biological reference sample.
Authors
Khateb, H; Hook, AL; Kern, S; Watts, JA; Singh, S; Jackson, D; Marinez-Pomares, L; Williams, P; Alexander, MRCollections
- Awaiting Allocation [225]