Detection of in situ derivatized peptides in microbial biofilms by laser desorption 7.87 eV postionizaton mass spectrometry.
A novel analytical method based on laser desorption postionization mass spectrometry (LDPI-MS) was developed to investigate the competence and sporulation factor-a pentapeptide of amino acid sequence ERGMT-within intact Bacillus subtilis biofilms. Derivatization of the neat ERGMT peptide with quinoline- and anthracene-based tags was separately used to lower the peptide ionization potential and permit direct ionization by 7.87-eV vacuum ultraviolet radiation. The techniques of mass shifting and selective ionization of the derivatized peptide were combined here to permit detection of ERGMT peptide within intact biofilms by LDPI-MS, without any prior extraction or chromatographic separation. Finally, imaging MS specific to the derivatized peptide was demonstrated on an intact biofilm using LDPI-MS. The presence of ERGMT in the biofilms was verified by bulk extraction/LC-MS. However, MALDI imaging MS analyses were unable to detect ERGMT within intact biofilms.
Edirisinghe
Praneeth D
PD
Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607-7061, USA.
Moore
Jerry F
JF
Skinner-Nemec
Kelly A
KA
Lindberg
Carl
C
Giometti
Carol S
CS
Veryovkin
Igor V
IV
Hunt
Jerry E
JE
Pellin
Michael J
MJ
Hanley
Luke
L
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000502:physiology*; D018441:Biofilms; D010455:Peptides / Q000032:analysis*; D053038:Quorum Sensing; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D010455:Peptides