title: Self-organization of glucose oxidase-polymer surfactant nanoconstructs in solvent-free soft solids and liquids.
abstract: An anisotropic glucose oxidase-polymer surfactant nanoconjugate is synthesized and shown to exhibit complex temperature-dependent phase behavior in the solvent-free state. At close to room temperature, the nanoconjugate crystallizes as a mesolamellar soft solid with an expanded interlayer spacing of ca. 12 nm and interchain correlation lengths consistent with alkyl tail-tail and PEO-PEO ordering. The soft solid displays a birefringent spherulitic texture and melts at 40 °C to produce a solvent-free liquid protein without loss of enzyme secondary structure. The nanoconjugate melt exhibits a birefringent dendritic texture below the conformation transition temperature (Tc) of glucose oxidase (58 °C) and retains interchain PEO-PEO ordering. Our results indicate that the shape anisotropy of the protein-polymer surfactant globular building block plays a key role in directing mesolamellar formation in the solvent-free solid and suggests that the microstructure observed in the solvent-free liquid protein below Tc is associated with restrictions in the intramolecular motions of the protein core of the nanoconjugate.
authors.affiliation: Centre for Organized Matter Chemistry and Centre for Protolife Research, School of Chemistry, ‡Bristol Centre for Functional Nanomaterials, and §School of Cellular and Molecular Medicine, University of Bristol , Bristol BS8 1TS, United Kingdom.
authors.forename: Kamendra P
authors.initials: KP
authors.lastname: Sharma
authors.forename: Yixiong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Michael R
authors.initials: MR
authors.lastname: Thomas
authors.forename: Alex P S
authors.initials: AP
authors.lastname: Brogan
authors.forename: Adam W
authors.initials: AW
authors.lastname: Perriman
authors.forename: Stephen
authors.initials: S
authors.lastname: Mann
mesh_terms: D002152:Calorimetry, Differential Scanning; D005949:Glucose Oxidase / Q000737:chemistry* / Q000378:metabolism; D058726:Nanoconjugates / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D053838:Scattering, Small Angle; D055672:Static Electricity; D013501:Surface-Active Agents / Q000737:chemistry*; D044366:Transition Temperature; D014961:X-Ray Diffraction
chemical_list: D058726:Nanoconjugates; D011108:Polymers; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; D005949:Glucose Oxidase