title: Dithiol amino acids can structurally shape and enhance the ligand-binding properties of polypeptides.
abstract: The disulfide bonds that form between two cysteine residues are important in defining and rigidifying the structures of proteins and peptides. In polypeptides containing multiple cysteine residues, disulfide isomerization can lead to multiple products with different biological activities. Here, we describe the development of a dithiol amino acid (Dtaa) that can form two disulfide bridges at a single amino acid site. Application of Dtaas to a serine protease inhibitor and a nicotinic acetylcholine receptor inhibitor that contain disulfide constraints enhanced their inhibitory activities 40- and 7.6-fold, respectively. X-ray crystallographic and NMR structure analysis show that the peptide ligands containing Dtaas have retained their native tertiary structures. We furthermore show that replacement of two cysteines by Dtaas can avoid the formation of disulfide bond isomers. With these properties, Dtaas are likely to have broad application in the rational design or directed evolution of peptides and proteins with high activity and stability.
authors.affiliation: Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Shiyu
authors.identifier: 000000016578561X
authors.initials: S
authors.lastname: Chen
authors.affiliation: Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Ranganath
authors.initials: R
authors.lastname: Gopalakrishnan
authors.affiliation: HiQScreen, CH-1022 Vésenaz, Geneva, Switzerland.
authors.forename: Tifany
authors.initials: T
authors.lastname: Schaer
authors.affiliation: HiQScreen, CH-1022 Vésenaz, Geneva, Switzerland.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Marger
authors.affiliation: Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Ruud
authors.identifier: 0000000192586587
authors.initials: R
authors.lastname: Hovius
authors.affiliation: HiQScreen, CH-1022 Vésenaz, Geneva, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bertrand
authors.affiliation: Protein Crystallography Core Facility, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Florence
authors.initials: F
authors.lastname: Pojer
authors.affiliation: Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Heinis
mesh_terms: D000596:Amino Acids / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D020134:Catalytic Domain; D020916:Conotoxins / Q000737:chemistry / Q000378:metabolism; D018360:Crystallography, X-Ray; D004220:Disulfides / Q000737:chemistry; D007536:Isomerism; D008024:Ligands; D056004:Molecular Dynamics Simulation; D018733:Nicotinic Antagonists / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000737:chemistry / Q000378:metabolism
chemical_list: D000596:Amino Acids; D020916:Conotoxins; D004220:Disulfides; D008024:Ligands; D018733:Nicotinic Antagonists; D010455:Peptides; D015842:Serine Proteinase Inhibitors; D014568:Urokinase-Type Plasminogen Activator