title: Novel structural features of the immunocompetent ceramide phospho-inositol glycan core from Trichomonas vaginalis.
abstract: The ceramide phosphoinositol glycan core (CPI-GC) of the lipophosphoglycan of Trichomonas vaginalis is a major virulent factor of this common genitourinary parasite. While its carbohydrate composition has been reported before, its structure has remained largely unknown. We isolated the glycan portions of CPI-GC by nitrous acid deamination and hydrofluoric acid treatment and investigated their structures by methylation analysis and 1- and 2-D NMR. We found that the α-anomer of galactose is a major constituent of CPI-GC. The β-anomer was found exclusively at the non-reducing end of CPI-GC side chains. Furthermore the data showed that the rhamnan backbone is more complex than previously thought and that the inositol residue at the reducing end is linked to a 4-linked α-glucuronic acid (GlcA) residue. This appears to be the most striking and novel feature of this GPI-anchor type molecule.
authors.affiliation: Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA. Electronic address: cheiss@uga.edu.
authors.forename: Christian
authors.initials: C
authors.lastname: Heiss
authors.affiliation: Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA.
authors.forename: Zhirui
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA.
authors.forename: Ian
authors.initials: I
authors.lastname: Black
authors.affiliation: Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA.
authors.forename: Parastoo
authors.initials: P
authors.lastname: Azadi
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: Raina N
authors.initials: RN
authors.lastname: Fichorova
authors.affiliation: Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY 13210, USA. Electronic address: singhb@upstate.edu.
authors.forename: Bibhuti N
authors.initials: BN
authors.lastname: Singh
mesh_terms: D002518:Ceramides / Q000737:chemistry*; D007294:Inositol / Q000031:analogs & derivatives* / Q000737:chemistry / Q000276:immunology; D009682:Magnetic Resonance Spectroscopy; D009608:Nitrous Acid / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry* / Q000276:immunology*; D014246:Trichomonas vaginalis / Q000737:chemistry*
chemical_list: D002518:Ceramides; D011134:Polysaccharides; C068698:inositol-glycan; D007294:Inositol; D009608:Nitrous Acid
keywords: Glycoconjugates; NMR; Phospho-inositol glycan core; Trichomonas vaginalis