title: A liquid chromatography-mass spectrometric method for the detection of cyclic β-amino fatty acid lipopeptides.
abstract: Bacterial lipopeptides, which contain β-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 β-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 10-55eV were used to obtain the amino acid composition of the peptide macrocycle. However, fragmentation energies of 90-130eV were used to obtain an intense fragment specific for the β-amino fatty acid (CnH2n+2N(+)). The method allowed the number of carbons and consequently the length of the β-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.
authors.affiliation: Centre Algatech, Institute of Microbiology, The Czech Academy of Sciences (CAS), Opatovický mlýn, 379 81, Třeboň, Czech Republic.
authors.forename: Petra
authors.initials: P
authors.lastname: Urajová
authors.affiliation: Centre Algatech, Institute of Microbiology, The Czech Academy of Sciences (CAS), Opatovický mlýn, 379 81, Třeboň, Czech Republic; University of South Bohemia, Faculty of Science, Branišovská 1760, České Budějovice, Czech Republic; Biology Centre of CAS, v.v.i., Institute of Hydrobiology, Na Sádkách 7, 370 05 České Budějovice, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Hájek
authors.affiliation: Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Wahlsten
authors.affiliation: Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Jouni
authors.initials: J
authors.lastname: Jokela
authors.affiliation: Centre Algatech, Institute of Microbiology, The Czech Academy of Sciences (CAS), Opatovický mlýn, 379 81, Třeboň, Czech Republic; University of South Bohemia, Faculty of Science, Branišovská 1760, České Budějovice, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Galica
authors.affiliation: Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: David P
authors.initials: DP
authors.lastname: Fewer
authors.affiliation: Centre Algatech, Institute of Microbiology, The Czech Academy of Sciences (CAS), Opatovický mlýn, 379 81, Třeboň, Czech Republic; University of South Bohemia, Faculty of Science, Branišovská 1760, České Budějovice, Czech Republic; Biology Centre of CAS, v.v.i., Institute of Hydrobiology, Na Sádkách 7, 370 05 České Budějovice, Czech Republic.
authors.forename: Andreja
authors.initials: A
authors.lastname: Kust
authors.affiliation: Biology Centre of CAS, v.v.i., Institute of Hydrobiology, Na Sádkách 7, 370 05 České Budějovice, Czech Republic.
authors.forename: Eliška
authors.initials: E
authors.lastname: Zapomělová-Kozlíková
authors.affiliation: Centre Algatech, Institute of Microbiology, The Czech Academy of Sciences (CAS), Opatovický mlýn, 379 81, Třeboň, Czech Republic; University of South Bohemia, Faculty of Science, Branišovská 1760, České Budějovice, Czech Republic.
authors.forename: Kateřina
authors.initials: K
authors.lastname: Delawská
authors.affiliation: Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Kaarina
authors.initials: K
authors.lastname: Sivonen
authors.affiliation: Centre Algatech, Institute of Microbiology, The Czech Academy of Sciences (CAS), Opatovický mlýn, 379 81, Třeboň, Czech Republic; University of South Bohemia, Faculty of Science, Branišovská 1760, České Budějovice, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Kopecký
authors.affiliation: Centre Algatech, Institute of Microbiology, The Czech Academy of Sciences (CAS), Opatovický mlýn, 379 81, Třeboň, Czech Republic; University of South Bohemia, Faculty of Science, Branišovská 1760, České Budějovice, Czech Republic. Electronic address: hrouzekp@gmail.com.
authors.forename: Pavel
authors.initials: P
authors.lastname: Hrouzek
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000935:Antifungal Agents / Q000032:analysis; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002853:Chromatography, Liquid; D000458:Cyanobacteria / Q000737:chemistry; D005227:Fatty Acids / Q000032:analysis; D055666:Lipopeptides / Q000032:analysis*; D013058:Mass Spectrometry
chemical_list: D000596:Amino Acids; D000935:Antifungal Agents; D005227:Fatty Acids; D055666:Lipopeptides
keywords: Bacteria; Cyanobacteria; Fatty acid; LC-HRMS; Lipopeptides; Peptide