title: Novel biocatalysts based on S-layer self-assembly of Geobacillus stearothermophilus NRS 2004/3a: a nanobiotechnological approach.
abstract: The crystalline cell-surface (S) layer sgsE of Geobacillus stearothermophilus NRS 2004/3a represents a natural protein self-assembly system with nanometer-scale periodicity that is evaluated as a combined carrier/patterning element for the conception of novel types of biocatalyst aiming at the controllable display of biocatalytic epitopes, storage stability, and reuse. The glucose-1-phosphate thymidylyltransferase RmlA is used as a model enzyme and chimeric proteins are constructed by translational fusion of rmlA to the C-terminus of truncated forms of sgsE (rSgsE (131-903), rSgsE(331-903)) and used for the construction of three principal types of biocatalysts: soluble (monomeric), self-assembled in aqueous solution, and recrystallized on negatively charged liposomes. Enzyme activity of the biocatalysts reaches up to 100 % compared to sole RmlA cloned from the same bacterium. The S-layer portion of the biocatalysts confers significantly improved shelf life to the fused enzyme without loss of activity over more than three months, and also enables biocatalyst recycling. These nanopatterned composites may open up new functional concepts for biocatalytic applications in nanobiotechnology.
authors.affiliation: University of Natural Resources and Applied Life Sciences, Center for NanoBiotechnology, Wien, Austria. christina.schaeffer@boku.ac.at
authors.forename: Christina
authors.initials: C
authors.lastname: Schäffer
authors.forename: René
authors.initials: R
authors.lastname: Novotny
authors.forename: Seta
authors.initials: S
authors.lastname: Küpcü
authors.forename: Sonja
authors.initials: S
authors.lastname: Zayni
authors.forename: Andrea
authors.initials: A
authors.lastname: Scheberl
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Friedmann
authors.forename: Uwe B
authors.initials: UB
authors.lastname: Sleytr
authors.forename: Paul
authors.initials: P
authors.lastname: Messner
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000648:ultrastructure; D001665:Binding Sites; D001709:Biotechnology / Q000379:methods*; D002384:Catalysis; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004800:Enzymes, Immobilized / Q000737:chemistry; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000648:ultrastructure; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D011485:Protein Binding; D013499:Surface Properties