title: Structural and immunological studies of an exopolysaccharide from Acinetobacter junii BB1A.
abstract: A water-soluble heteropolysaccharide (PS) was isolated from extracellular polymeric substances (EPS) produced by a novel metal tolerant bacterium, Acinetobacter junii BB1A. Sugar analysis showed that the PS was composed of mannose, galactose and arabinose in a molar ratio of nearly 3:1:1. Structural characterization of the PS was carried out using methylation analysis, periodate oxidation, Smith degradation and 1D/2D NMR experiments. Methylation analysis revealed that the PS was consisted of 2,4-linked-mannopyranosyl, 3,4-linked-mannopyranosyl, 2-linked-galactopyranosyl, terminal mannopyranosyl and arabinopyranosyl residues in a relative proportion of nearly 1:1:1:1:1. Smith degradation of the PS showed the presence of hydrated glyceraldehyde containing disaccharide unit consisting of α-d-Manp-(1→and→4)-α-d-Manp-(1→residues where the later was directly attached to a hydrated glyceraldehyde moiety. This polysaccharide showed significant in vitro splenocyte, thymocyte, and macrophage activations with optimum dose of 100 μg/mL for macrophage and 25 μg/mL both for the splenocyte and thymocyte.
authors.affiliation: Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore 721102, West Bengal, India.
authors.forename: Ipsita Kumar
authors.initials: IK
authors.lastname: Sen
authors.forename: Amit Kumar
authors.initials: AK
authors.lastname: Mandal
authors.forename: Ranadhir
authors.initials: R
authors.lastname: Chakraborty
authors.forename: Birendra
authors.initials: B
authors.lastname: Behera
authors.forename: Krishna Kant
authors.initials: KK
authors.lastname: Yadav
authors.forename: Tapas Kumar
authors.initials: TK
authors.lastname: Maiti
authors.forename: Syed Sirajul
authors.initials: SS
authors.lastname: Islam
mesh_terms: D000150:Acinetobacter / Q000737:chemistry*; D000818:Animals; D002240:Carbohydrate Sequence; D002460:Cell Line; D004187:Disaccharides / Q000378:metabolism; D008262:Macrophage Activation / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D004187:Disaccharides; D011135:Polysaccharides, Bacterial
keywords: Acinetobacter junii BB1A; Heteropolysaccharide; Immunoactivation; NMR; Structural characterization