title: Pickering stabilized peptide gel particles as tunable microenvironments for biocatalysis.
abstract: We demonstrate the preparation of peptide gel microparticles that are emulsified and stabilized by SiO2 nanoparticles. The gels are composed of aromatic peptide amphiphiles 9-fluorenylmethoxycarbonyldiphenylalanine (Fmoc-FF) coassembled with Fmoc-amino acids with different functional groups (S: serine; D: aspartic acid; K: lysine; and Y: tyrosine). The gel phase provides a highly hydrated matrix, and peptide self-assembly endows the matrix with tunable chemical environments which may be exploited to support and stabilize proteins. The use of Pickering emulsion to stabilize these gel particles is advantageous through avoidance of surfactants that may denature proteins. The performance of enzyme lipase B immobilized in pickering/gel microparticles with different chemical functionalities is investigated by studying transesterification in heptane. We show that the use of Pickering particles enhances the performance of the enzyme, which is further improved in gel-phase systems, with hydrophilic environment provided by Fmoc-FF/S giving rise to the best catalytic performance. The combination of a tunable chemical environment in gel phase and Pickering stabilization described here is expected to prove useful for areas where proteins are to be exploited in technological contexts such as biocatalysis and also in other areas where protein performance and activity are important, such as biosensors and bioinspired solar fuel devices.
authors.affiliation: WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, U.K.
authors.forename: Gary
authors.initials: G
authors.lastname: Scott
authors.forename: Sangita
authors.initials: S
authors.lastname: Roy
authors.forename: Yousef M
authors.initials: YM
authors.lastname: Abul-Haija
authors.forename: Scott
authors.initials: S
authors.lastname: Fleming
authors.forename: Shuo
authors.initials: S
authors.lastname: Bai
authors.forename: Rein V
authors.initials: RV
authors.lastname: Ulijn
mesh_terms: D055162:Biocatalysis; D002210:Caprylates / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D004951:Esterification; D005449:Fluorenes / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D005782:Gels; D006536:Heptanes / Q000737:chemistry; D008049:Lipase / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry; D000442:Octanols / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: C496789:9-fluorenylmethoxycarbonyl; D002210:Caprylates; D004800:Enzymes, Immobilized; D005449:Fluorenes; D005656:Fungal Proteins; D005782:Gels; D006536:Heptanes; D000442:Octanols; D010455:Peptides; D012822:Silicon Dioxide; D008049:Lipase; C431349:lipase B, Candida antarctica; C031492:octanoic acid