title: The structures of glycolipids isolated from the highly thermophilic bacterium Thermus thermophilus Samu-SA1.
abstract: Thermophiles constitute a class of microorganisms able to grow at extremely elevated temperatures. Some of these species are classified as Gram-negative bacteria, because of the presence of an outer membrane in the cell envelope, which is located on the top of a thick murein layer. Unlike typical Gram-negative bacteria, the outer membranes of Thermus species are not composed of lipopolysaccharides but of peculiar glycolipids (GL), whose structures seem to be strictly involved in the adaptation to high temperatures. In this work, the complete structures of the major GL components from the cell envelope of the thermophilic bacterium Thermus thermophilus Samu-SA1 are presented. Protocols conventionally adopted for Gram-negative bacteria were used, and, for the first time, GL from Thermus were analyzed in their native form. Two GL and one phosphoglycolipid (PGL) were detected and characterized. The two GL, analyzed by nuclear magnetic resonance (NMR) spectroscopy and electrospray ionization Fourier transform ion cyclotron resonance (ESI FT-ICR) mass spectrometry, possessed the same tetrasaccharide structure linked to a glycerol unit or, alternatively, to a long-chain diol. Moreover, a PGL from Thermus was characterized for the first time, in which N-glyceroyl-heptadecaneamine was present. These molecules are chemically related to other GL from thermophile bacteria, in which they play a crucial role in the adaptation of cell membranes to heat.
authors.affiliation: Dipartimento di Chimica Organica e Biochimica, Università degli Studi di Napoli Federico II, Via Cintia 4, I-80126 Napoli, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Leone
authors.forename: Antonio
authors.initials: A
authors.lastname: Molinaro
authors.forename: Buko
authors.initials: B
authors.lastname: Lindner
authors.forename: Ida
authors.initials: I
authors.lastname: Romano
authors.forename: Barbara
authors.initials: B
authors.lastname: Nicolaus
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Parrilli
authors.forename: Rosa
authors.initials: R
authors.lastname: Lanzetta
authors.forename: Otto
authors.initials: O
authors.lastname: Holst
mesh_terms: D017357:Cyclotrons; D005583:Fourier Analysis; D008401:Gas Chromatography-Mass Spectrometry; D006017:Glycolipids / Q000032:analysis* / Q000302:isolation & purification; D008563:Membrane Lipids / Q000032:analysis* / Q000302:isolation & purification; D015394:Molecular Structure; D008970:Molecular Weight; D019906:Nuclear Magnetic Resonance, Biomolecular; D010743:Phospholipids / Q000032:analysis* / Q000302:isolation & purification; D021241:Spectrometry, Mass, Electrospray Ionization; D016963:Thermus thermophilus / Q000737:chemistry* / Q000254:growth & development
chemical_list: D006017:Glycolipids; D008563:Membrane Lipids; D010743:Phospholipids