title: A synthetic peptide encompassing the binding site of the second zinc atom (the 'structural' zinc) of alcohol dehydrogenase.
abstract: A 23-residue peptide was synthesized that incorporates the loop which binds the structural zinc atom of mammalian alcohol dehydrogenases and contributes, in part, to subunit interactions in the native enzyme. Neither the amino acid composition nor the sequence of the peptide resemble those of zinc fingers. The reduced peptide stoichiometrically binds zinc or cobalt to form stable complexes with a dissociation constant of the peptide/CO2+ complex of 2.1 microM at pH 7.5. EDTA disrupts the complex. The absorption and magnetic circular dichroic spectra of the cobalt-peptide are indicative of a tetrahedral coordination geometry, and are similar to those of the cobalt-substituted structural site of horse and human (beta 1 beta 1) liver alcohol dehydrogenases. Consequently, the synthetic peptide can serve as a model for the metal-binding segment of alcohol dehydrogenase and for studies of fundamental problems concerning protein/metal interactions.
authors.affiliation: Department of Chemistry I, Karolinska Institutet, Stockholm, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Bergman
authors.forename: H
authors.initials: H
authors.lastname: Jörnvall
authors.forename: B
authors.initials: B
authors.lastname: Holmquist
authors.forename: B L
authors.initials: BL
authors.lastname: Vallee
mesh_terms: D000426:Alcohol Dehydrogenase / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D001665:Binding Sites; D002942:Circular Dichroism; D003035:Cobalt / Q000378:metabolism; D004492:Edetic Acid / Q000494:pharmacology; D007700:Kinetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation; D013053:Spectrophotometry; D015032:Zinc / Q000378:metabolism*
chemical_list: D010446:Peptide Fragments; D003035:Cobalt; D004492:Edetic Acid; D000426:Alcohol Dehydrogenase; D015032:Zinc