Detection and identification of Bacteriovorax stolpii UKi2 sphingophosphonolipid molecular species

Abstract

Bacteriovorax stolpii is a predator of larger gram-negative bacteria and lives as a parasite in the intraperiplasmic space of the host cell. This bacterium is unusual among prokaryotes in that sphingolipids comprise a large proportion of its lipids. We here report the presence of 18 molecular species of B. stolpii UKi2 sphingophosphonolipids (SPNLs).31 P NMR spectroscopy and analysis of P i released by a differential hydrolysis protocol confirmed the phosphonyl nature of these lipids. The SPNLs were dominated by those with 1-hydroxy-2-aminoethane phosphonate (hydroxy-aminoethylphosphonate) polar head groups; aminoethylphosphonate was also detected in minor SPNL components. The long-chain bases (LCBs) were dominated by C 17 iso-branched phytosphingosine; C 17 iso-branched dihydrosphingosine was also present in some SPNLs. The N-linked fatty acids were predominantly iso-branched and most contained an ␣-hydroxy group (C 15 ␣-hydroxy fatty acid was the major fatty acid). Minor molecular species containing nonhydroxy fatty acids were also detected. The definitive iso-structures of the predominant fatty acids and LCBs present in the B. stolpii SPNLs were established using 13 C and 3 H nuclear magnetic resonance spectroscopy; less than 20% were unbranched. Detection and analyses of intact compounds by MS-MS were performed by a hybrid quadrupole time-of-flight (Q-TOF-II) MS equipped with an electrospray ionization source. Analyses of peracetylated derivatives verified the structural assignments of these lipids. (J Am Soc Mass Spectrom 2007, 18, 394 -403)

Unusual Outer Membrane Lipid Composition of the Gram-negative, Lipopolysaccharide-lacking Myxobacterium Sorangium cellulosum So ce56

“…They were only described in the sea anemone Metridium senile (42), the bacterium Bacteriovorax stolpii (43), and the protozoan Tetrahymena thermophila (44). Interestingly, phosphonosphingolipids of Bacteriovorax stolpii UKi2 show sensitivity to phospholipase C and resistance to phospholipase D (45). In this context, the close phylogenetic relationship of myxobacteria to Bacteriovorax has to be mentioned (5).…”

Bacterial Predators Possess Unique Membrane Lipid Structures

“…Sphingophosphonolipids (SPNL) were separated from the glycerophospholipid (GPL) species by mild alkaline methanolysis [9] or by incubation of a total phospholipid extract with lipase D (personal communication, Sabine Schiller, Department of Biology, Humboldt-Universität zu Berlin). For the enzymatic assay, 0.3 mg of a total phospholipid extract were dissolved in 183.3 ll of ethyl acetate and 83.3 ll of an acetate buffer (0.2 M sodium acetate, 40 mM calcium chloride, pH 8.0) were added.…”

A Validated Time of Flight Mass Spectrometry for Quantitative Determination of Amantadine Hydrochloride and Memantine Hydrochloride

“…Time-of-flight mass spectrometer (TOF-MS) delivers high sensitivity, resolution, and exact mass measurements. A variety of ion source and software options makes MS a versatile choice for a range of analytical challenges [1][2][3][4].…”