Structural investigation of cyclic peptidolipids from Bacillus subtilis by high-energy tandem mass spectrometry.
The natural products belonging to the surfactin family are cycloheptapeptides bearing a long beta-hydroxy-fatty acyl chain at the N-terminal position. The structure of these compounds, often isolated as complex mixtures, can be elucidated by high-energy tandem mass spectrometry (MS/MS). The protonated molecules generated by cesium ion bombardment (LSIMS) undergo charge-proximate fragmentations leading to the b- and y-type ion series useful for the sequence determination. The sodium-cationised molecules show a radically different behaviour towards high-energy collisional activation. Besides the well-known charge-remote dissociation products of the alkyl side chain, complete series of d- and w-type fragments allow easy distinction between leucine and isoleucine. The complementary MS/MS data obtained from the protonated and cationised molecules prove to be of great interest for the structural characterisation of this type of compounds.
Hue
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Institut de Chimie des Substances Naturelles, CNRS, avenue de la Terrasse, 91198 Gif-sur-Yvette, France.
Serani
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Laprévote
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O
D001412:Bacillus subtilis / Q000737:chemistry*; D001426:Bacterial Proteins / Q000032:analysis*; D055666:Lipopeptides; D008074:Lipoproteins / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*; D010456:Peptides, Cyclic; D011487:Protein Conformation; D013501:Surface-Active Agents / Q000032:analysis*
D001426:Bacterial Proteins; D055666:Lipopeptides; D008074:Lipoproteins; D010456:Peptides, Cyclic; D013501:Surface-Active Agents; C009365:surfactin peptide