A liquid chromatography-mass spectrometric method for the detection of cyclic beta-amino fatty acid lipopeptides

0464600 - MBÚ 2017 RIV NL eng J - Journal Article
Urajová, Petra - Hájek, Jan - Wahlsten, M. - Jokela, J. - Galica, Tomáš - Fewer, D.P. - Kust, Andreja - Zapomělová-Kozlíková, E. - Delawská, Kateřina - Sivonen, K. - Kopecký, Jiří - Hrouzek, Pavel
A liquid chromatography-mass spectrometric method for the detection of cyclic beta-amino fatty acid lipopeptides.
Journal of Chromatography A. Roč. 1438, MARCH 18 (2016), s. 76-83. ISSN 0021-9673. E-ISSN 1873-3778
R&D Projects: GA MŠMT(CZ) LO1416; GA ČR(CZ) GA14-18067S; GA ČR(CZ) GA16-09381S
Institutional support: RVO:61388971
Keywords : Lipopeptides * Bacteria * Cyanobacteria
Subject RIV: EE - Microbiology, Virology
Impact factor: 3.981, year: 2016

Bacterial lipopeptides, which contain beta-amino fatty acids, are an abundant group of bacterial secondary metabolites exhibiting antifungal and/or cytotoxic properties. Here we have developed an LC-HRMS/MS method for the selective detection of beta-amino fatty acid containing cyclic lipopeptides. The method was optimized using the lipopeptides iturin A and puwainaphycin F, which contain fatty acids of similar length but differ in the amino acid composition of the peptide cycle. Fragmentation energies of 10-55 eV were used to obtain the amino acid composition of the peptide macrocycle. However, fragmentation energies of 90-130 eV were used to obtain an intense fragment specific for the beta-amino fatty acid (CnH2n+2N+). The method allowed the number of carbons and consequently the length of the beta-amino fatty acid to be estimated. We identified 21 puwainaphycin variants differing in fatty acid chain in the crude extract of cyanobacterium Cylindrospermum alatosporum using this method. Analogously 11 iturin A variants were detected. The retention time of the lipopeptide variants showed a near perfect linear dependence (R-2=0.9995) on the length of the fatty acid chain in linear separation gradient which simplified the detection of minor variants. We used the method to screen 240 cyanobacterial strains and identified lipopeptides from 8 strains. The HPLC-HRMS/MS method developed here provides a rapid and easy way to detecting novel variants of cyclic lipopeptides.
Permanent Link: http://hdl.handle.net/11104/0263751