title: Selection of novel structural zinc sites from a random peptide library.
abstract: Zinc ion (Zn(2+)) can be coordinated with four or three amino acid residues to stabilize a protein's structure or to form a catalytic active center. We used phage display selection of a dodecamer random peptide library with Zn(2+) to identify structural zinc sites. The binding specificity for Zn(2+) of selected sequences was confirmed using enzyme-linked immunosorbent and competitive inhibition assays. Circular dichroism spectra indicated that the interaction with Zn(2+) induced a change in conformation, which means the peptide acts as a structural zinc site. Furthermore, a search of protein databases revealed that two selected sequences corresponded to parts of natural zinc sites of copper/zinc superoxide dismutase and zinc-containing ferredoxin. We demonstrated that Zn(2+)-binding sequences selected from the random combinatorial library would be candidates for artificial structural zinc sites.
authors.affiliation: Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan. matsubara@bio.keio.ac.jp
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Matsubara
authors.forename: Yuko
authors.initials: Y
authors.lastname: Hiura
authors.forename: Osamu
authors.initials: O
authors.lastname: Kawahito
authors.forename: Mikito
authors.initials: M
authors.lastname: Yasuzawa
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Kawashiro
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D002942:Circular Dichroism; D004797:Enzyme-Linked Immunosorbent Assay; D005288:Ferredoxins / Q000235:genetics / Q000378:metabolism; D019216:Metals, Heavy / Q000378:metabolism; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D015032:Zinc / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005288:Ferredoxins; D019216:Metals, Heavy; D019151:Peptide Library; D010455:Peptides; D013482:Superoxide Dismutase; D015032:Zinc