title: Structural basis of IL-23 antagonism by an Alphabody protein scaffold.
abstract: Protein scaffolds can provide a promising alternative to antibodies for various biomedical and biotechnological applications, including therapeutics. Here we describe the design and development of the Alphabody, a protein scaffold featuring a single-chain antiparallel triple-helix coiled-coil fold. We report affinity-matured Alphabodies with favourable physicochemical properties that can specifically neutralize human interleukin (IL)-23, a pivotal therapeutic target in autoimmune inflammatory diseases such as psoriasis and multiple sclerosis. The crystal structure of human IL-23 in complex with an affinity-matured Alphabody reveals how the variable interhelical groove of the scaffold uniquely targets a large epitope on the p19 subunit of IL-23 to harness fully the hydrophobic and hydrogen-bonding potential of tryptophan and tyrosine residues contributed by p19 and the Alphabody, respectively. Thus, Alphabodies are suitable for targeting protein-protein interfaces of therapeutic importance and can be tailored to interrogate desired design and binding-mode principles via efficient selection and affinity-maturation strategies.
authors.affiliation: 1] COMPLIX N.V., Technology Park 4, 9052 Ghent, Belgium [2].
authors.forename: Johan
authors.initials: J
authors.lastname: Desmet
authors.affiliation: 1] Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Department of Biochemistry and Microbiology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium [2].
authors.forename: Kenneth
authors.initials: K
authors.lastname: Verstraete
authors.affiliation: Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Department of Biochemistry and Microbiology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.
authors.forename: Yehudi
authors.initials: Y
authors.lastname: Bloch
authors.affiliation: COMPLIX N.V., Technology Park 4, 9052 Ghent, Belgium.
authors.forename: Eric
authors.initials: E
authors.lastname: Lorent
authors.affiliation: 1] Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Department of Biochemistry and Microbiology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium [2] Unit for Biological Mass spectrometry and Proteomics, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Department of Biochemistry and Microbiology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.
authors.forename: Yurong
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Unit for Biological Mass spectrometry and Proteomics, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Department of Biochemistry and Microbiology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: Devreese
authors.affiliation: COMPLIX N.V., Technology Park 4, 9052 Ghent, Belgium.
authors.forename: Karen
authors.initials: K
authors.lastname: Vandenbroucke
authors.affiliation: COMPLIX N.V., Technology Park 4, 9052 Ghent, Belgium.
authors.forename: Stefan
authors.initials: S
authors.lastname: Loverix
authors.affiliation: COMPLIX N.V., Technology Park 4, 9052 Ghent, Belgium.
authors.forename: Thore
authors.initials: T
authors.lastname: Hettmann
authors.affiliation: COMPLIX N.V., Technology Park 4, 9052 Ghent, Belgium.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Deroo
authors.affiliation: COMPLIX N.V., Technology Park 4, 9052 Ghent, Belgium.
authors.forename: Klaartje
authors.initials: K
authors.lastname: Somers
authors.affiliation: COMPLIX N.V., Technology Park 4, 9052 Ghent, Belgium.
authors.forename: Paula
authors.initials: P
authors.lastname: Henderikx
authors.affiliation: COMPLIX N.V., Technology Park 4, 9052 Ghent, Belgium.
authors.forename: Ignace
authors.initials: I
authors.lastname: Lasters
authors.affiliation: Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Department of Biochemistry and Microbiology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.
authors.forename: Savvas N
authors.initials: SN
authors.lastname: Savvides
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D004353:Drug Evaluation, Preclinical; D006801:Humans; D053759:Interleukin-23 / Q000037:antagonists & inhibitors*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000627:therapeutic use; D011565:Psoriasis / Q000517:prevention & control
chemical_list: D053759:Interleukin-23; D010455:Peptides