title: Artificial Avidin-Based Receptors for a Panel of Small Molecules.
abstract: Proteins with high specificity, affinity, and stability are needed for biomolecular recognition in a plethora of applications. Antibodies are powerful affinity tools, but they may also suffer from limitations such as low stability and high production costs. Avidin and streptavidin provide a promising scaffold for protein engineering, and due to their ultratight binding to D-biotin they are widely used in various biotechnological and biomedical applications. In this study, we demonstrate that the avidin scaffold is suitable for use as a novel receptor for several biologically active small molecules: Artificial, chicken avidin-based proteins, antidins, were generated using a directed evolution method for progesterone, hydrocortisone, testosterone, cholic acid, ketoprofen, and folic acid, all with micromolar to nanomolar affinity and significantly reduced biotin-binding affinity. We also describe the crystal structure of an antidin, sbAvd-2(I117Y), a steroid-binding avidin, which proves that the avidin scaffold can tolerate significant modifications without losing its characteristic tetrameric beta-barrel structure, helping us to further design avidin-based small molecule receptors.
authors.affiliation: BioMediTech, University of Tampere , Biokatu 6, FI-33014 Tampere, Finland.
authors.forename: Soili I
authors.initials: SI
authors.lastname: Lehtonen
authors.affiliation: VTT Technical Research Centre of Finland , Tietotie 2, FI-02044 Espoo, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Tullila
authors.affiliation: Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , Tykistökatu 6A, FI-20520 Turku, Finland.
authors.forename: Nitin
authors.initials: N
authors.lastname: Agrawal
authors.affiliation: BioMediTech, University of Tampere , Biokatu 6, FI-33014 Tampere, Finland.|Fimlab Laboratories , Biokatu 4, FI-33520 Tampere, Finland.
authors.forename: Sampo
authors.initials: S
authors.lastname: Kukkurainen
authors.affiliation: BioMediTech, University of Tampere , Biokatu 6, FI-33014 Tampere, Finland.
authors.forename: Niklas
authors.initials: N
authors.lastname: Kähkönen
authors.affiliation: BioMediTech, University of Tampere , Biokatu 6, FI-33014 Tampere, Finland.
authors.forename: Masi
authors.initials: M
authors.lastname: Koskinen
authors.affiliation: VTT Technical Research Centre of Finland , Tietotie 2, FI-02044 Espoo, Finland.
authors.forename: Tarja K
authors.initials: TK
authors.lastname: Nevanen
authors.affiliation: Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , Tykistökatu 6A, FI-20520 Turku, Finland.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Johnson
authors.affiliation: Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , Tykistökatu 6A, FI-20520 Turku, Finland.
authors.forename: Tomi T
authors.initials: TT
authors.lastname: Airenne
authors.affiliation: BioMediTech, University of Tampere , Biokatu 6, FI-33014 Tampere, Finland.
authors.forename: Markku S
authors.initials: MS
authors.lastname: Kulomaa
authors.affiliation: BioMediTech, University of Tampere , Biokatu 6, FI-33014 Tampere, Finland.
authors.forename: Tiina A
authors.initials: TA
authors.lastname: Riihimäki
authors.affiliation: BioMediTech, University of Tampere , Biokatu 6, FI-33014 Tampere, Finland.|Fimlab Laboratories , Biokatu 4, FI-33520 Tampere, Finland.
authors.forename: Vesa P
authors.initials: VP
authors.lastname: Hytönen
mesh_terms: D000818:Animals; D001360:Avidin / Q000737:chemistry / Q000378:metabolism*; D001681:Biological Assay / Q000379:methods*; D002152:Calorimetry, Differential Scanning; D002645:Chickens; D018360:Crystallography, X-Ray; D005470:Fluorometry; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D062165:Receptors, Artificial / Q000737:chemistry / Q000187:drug effects*; D054852:Small Molecule Libraries / Q000737:chemistry / Q000378:metabolism*
chemical_list: D062165:Receptors, Artificial; D054852:Small Molecule Libraries; D001360:Avidin