title: A unique glyceryl diglycoside identified in the thermophilic, radiation-resistant bacterium Rubrobacter xylanophilus.
abstract: The solute pool of the actinobacterium Rubrobacter xylanophilus has been investigated as a function of the growth temperature and concentration of NaCl in the medium (Empadinhas et al. Extremophiles 11: 667-673, 2007). Changing the carbon source from glucose to maltose in a minimal growth medium led to the accumulation of an unknown organic compound whose structure was investigated by NMR and confirmed by chemical synthesis in the present study as: (2R)-2-(1-O-α-D-mannopyranosyl)-3-(1-O-α-D-glucopyranosyl)-D-glycerate (MGlyG). In addition to this newly identified diglycoside, the solute pool of R. xylanophilus included trehalose, mannosylglycerate, di-myo-inositol phosphate and di-N-acetyl-glucosamine phosphate. The structure of MGlyG was established by NMR and confirmed by chemical synthesis. The availability of g-amounts of the synthetic material allowed us to perform stabilization tests on three model enzymes (malate dehydrogenase, staphylococcal nuclease, and lysozyme), and compare the efficacy of MGlyG with other natural glyceryl glycosides, such as α-D-mannosyl-D-glycerate, α-D-glucosyl-D-glycerate and α-D-glucosyl-(1 → 6)-α-D-glucosyl-(1 → 2)-D-glycerate.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República-EAN, Apartado 127, 2780-157, Oeiras, Portugal, lamosa@itqb.unl.pt.
authors.forename: Pedro
authors.initials: P
authors.lastname: Lamosa
authors.forename: Eva C
authors.initials: EC
authors.lastname: Lourenço
authors.forename: Filipa
authors.initials: F
authors.lastname: d'Avó
authors.forename: Ana
authors.initials: A
authors.lastname: Nobre
authors.forename: Tiago M
authors.initials: TM
authors.lastname: Bandeiras
authors.forename: Milton S
authors.initials: MS
authors.lastname: da Costa
authors.forename: M Rita
authors.initials: MR
authors.lastname: Ventura
authors.forename: Helena
authors.initials: H
authors.lastname: Santos
mesh_terms: D039903:Actinobacteria / Q000737:chemistry / Q000378:metabolism*; D002240:Carbohydrate Sequence; D005988:Glyceric Acids / Q000737:chemistry* / Q000378:metabolism; D006017:Glycolipids / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D006027:Glycosides / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data
chemical_list: D005988:Glyceric Acids; D006017:Glycolipids; D006027:Glycosides