title: Discovery of 12-mer peptides that bind to wood lignin.
abstract: Lignin, an abundant terrestrial polymer, is the only large-volume renewable feedstock composed of an aromatic skeleton. Lignin has been used mostly as an energy source during paper production; however, recent interest in replacing fossil fuels with renewable resources has highlighted its potential value in providing aromatic chemicals. Highly selective degradation of lignin is pivotal for industrial production of paper, biofuels, chemicals, and materials. However, few studies have examined natural and synthetic molecular components recognizing the heterogeneous aromatic polymer. Here, we report the first identification of lignin-binding peptides possessing characteristic sequences using a phage display technique. The consensus sequence HFPSP was found in several lignin-binding peptides, and the outer amino acid sequence affected the binding affinity of the peptides. Substitution of phenylalanine7 with Ile in the lignin-binding peptide C416 (HFPSPIFQRHSH) decreased the affinity of the peptide for softwood lignin without changing its affinity for hardwood lignin, indicating that C416 recognised structural differences between the lignins. Circular dichroism spectroscopy demonstrated that this peptide adopted a highly flexible random coil structure, allowing key residues to be appropriately arranged in relation to the binding site in lignin. These results provide a useful platform for designing synthetic and biological catalysts selectively bind to lignin.
authors.affiliation: Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan.
authors.forename: Asako
authors.initials: A
authors.lastname: Yamaguchi
authors.affiliation: Institute for Chemical Research, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Isozaki
authors.affiliation: Institute for Chemical Research, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Institute for Chemical Research, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Takaya
authors.affiliation: Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001665:Binding Sites; D056804:Biofuels; D018533:Biomass; D002942:Circular Dichroism; D008031:Lignin / Q000737:chemistry*; D008958:Models, Molecular; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D017433:Protein Structure, Secondary; D014934:Wood / Q000737:chemistry*
chemical_list: D056804:Biofuels; D019151:Peptide Library; D010455:Peptides; D008031:Lignin