MALDI-TOF-MS detection of the low molecular weight neurotoxins anatoxin-a and homoanatoxin-a on lyophilized and fresh filaments of axenic Oscillatoria strains.
Anatoxin-a (ANTX) and homoanatoxin-a (HANTX) are low molecular weight neurotoxic secondary amines of 165 and 179 Da, respectively. We applied matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) for the detection of ANTX and HANTX directly on lyophilized and fresh filaments of axenic strains of the genus Oscillatoria, using 2,5-dihydroxybenzoic acid as matrix and purified ANTX and HANTX as references. To counteract the span of low molecular mass ions (< m/z 1000) generated by the matrix, we induced the matrix-suppression effect to obtain high quality ANTX/HANTX MALDI signals. MALDI desorption/ionization of the matrix-ANTX and the matrix-HANTX generated protonated molecules [M+H](+) at m/z 166.12322 and 180.1372, respectively. The masses obtained from the analysis of lyophilized filaments of the ANTX-producer Oscillatoria sp. strain PCC 9240 (m/z 166.15) and of fresh filaments of the HANTX-producers Oscillatoria sp. strains PCC 6506 (m/z 180.1375), PCC 9029 (m/z 180.1334) and PCC 10111 (m/z 180.13996) corresponded to the protonated molecular ions of ANTX and HANTX, respectively. Therefore, the application of MALDI-TOF-MS for the detection of cyanobacterial anatoxins in clonal and axenic strains of the cyanobacterial culture collections worldwide may help to assess ANTX/HANTX incidence among cyanobacteria.
Aráoz
Rómulo
R
CNRS, Institut de Neurobiologie Alfred Fessard - FRC2118, Laboratoire de Neurobiologie Cellulaire et Moléculaire - UPR9040, 91198 Gif sur Yvette, France. araoz@nbcm.cnrs-gif.fr
Guérineau
Vincent
V
Rippka
Rosmarie
R
Palibroda
Nicolae
N
Herdman
Michael
M
Laprevote
Olivier
O
von Döhren
Hans
H
de Marsac
Nicole Tandeau
NT
Erhard
Marcel
M
D017033:Anabaena / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000032:analysis* / Q000737:chemistry; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000032:analysis* / Q000737:chemistry; D000087522:Cyanobacteria Toxins; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D008970:Molecular Weight; D009498:Neurotoxins / Q000032:analysis* / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014326:Tropanes / Q000032:analysis* / Q000737:chemistry
D001427:Bacterial Toxins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D000087522:Cyanobacteria Toxins; D009498:Neurotoxins; D014326:Tropanes; C524097:homoanatoxin-a; C509783:anatoxin a