title: A glycoconjugate of Haemophilus influenzae Type b capsular polysaccharide with tetanus toxoid protein: hydrodynamic properties mainly influenced by the carbohydrate.
abstract: Three important physical properties which may affect the performance of glycoconjugate vaccines against serious disease are molar mass (molecular weight), heterogeneity (polydispersity), and conformational flexibility in solution. The dilute solution behaviour of native and activated capsular polyribosylribitol (PRP) polysaccharides extracted from Haemophilus influenzae type b (Hib), and the corresponding glycoconjugate made by conjugating this with the tetanus toxoid (TT) protein have been characterized and compared using a combination of sedimentation equilibrium and sedimentation velocity in the analytical ultracentrifuge with viscometry. The weight average molar mass of the activated material was considerably reduced (Mw ~ 0.24 × 10(6) g.mol(-1)) compared to the native (Mw ~ 1.2 × 10(6) g.mol(-1)). Conjugation with the TT protein yielded large polydisperse structures (of Mw ~ 7.4 × 10(6) g.mol(-1)), but which retained the high degree of flexibility of the native and activated polysaccharide, with frictional ratio, intrinsic viscosity, sedimentation conformation zoning behaviour and persistence length all commensurate with highly flexible coil behaviour and unlike the previously characterised tetanus toxoid protein (slightly extended and hydrodynamically compact structure with an aspect ratio of ~3). This non-protein like behaviour clearly indicates that it is the carbohydrate component which mainly influences the physical behaviour of the glycoconjugate in solution.
authors.affiliation: National Centre for Macromolecular Hydrodynamics, University of Nottingham, Sutton Bonington LE12 5RD, UK.|Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.
authors.forename: Ali Saber
authors.initials: AS
authors.lastname: Abdelhameed
authors.affiliation: National Centre for Macromolecular Hydrodynamics, University of Nottingham, Sutton Bonington LE12 5RD, UK.|Insulin and Diabetes Experimental Research (IDER) Group, University of Nottingham, Faculty of Medicine and Health Science, Clifton Boulevard, Nottingham, NG7 2RD UK.
authors.forename: Gary G
authors.initials: GG
authors.lastname: Adams
authors.affiliation: National Centre for Macromolecular Hydrodynamics, University of Nottingham, Sutton Bonington LE12 5RD, UK.|Department of Chemical Sciences, School of Applied Science, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK.
authors.forename: Gordon A
authors.initials: GA
authors.lastname: Morris
authors.affiliation: National Centre for Macromolecular Hydrodynamics, University of Nottingham, Sutton Bonington LE12 5RD, UK.
authors.forename: Fahad M
authors.initials: FM
authors.lastname: Almutairi
authors.affiliation: GSK Vaccines, Rue de l'Institut 89, B-1330 Rixensart, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Duvivier
authors.affiliation: GSK Vaccines, Rue de l'Institut 89, B-1330 Rixensart, Belgium.
authors.forename: Karel
authors.initials: K
authors.lastname: Conrath
authors.affiliation: National Centre for Macromolecular Hydrodynamics, University of Nottingham, Sutton Bonington LE12 5RD, UK.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Harding
mesh_terms: D000942:Antigens, Bacterial / Q000276:immunology / Q000502:physiology*; D002499:Centrifugation, Density Gradient; D006001:Glycoconjugates / Q000276:immunology / Q000502:physiology*; D018073:Haemophilus Vaccines / Q000276:immunology; D019741:Haemophilus influenzae type b / Q000276:immunology / Q000472:pathogenicity*; D006801:Humans; D057446:Hydrodynamics; D011135:Polysaccharides, Bacterial / Q000276:immunology / Q000502:physiology*; D013745:Tetanus Toxoid / Q000276:immunology / Q000378:metabolism; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D006001:Glycoconjugates; D018073:Haemophilus Vaccines; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid; D018074:Vaccines, Conjugate