title: A cobalt complex that selectively disrupts the structure and function of zinc fingers.
abstract: Zinc finger domains are structures that mediate sequence recognition for a large number of DNA-binding proteins. These domains consist of sequences of amino acids containing cysteine and histidine residues tetrahedrally coordinated to a zinc ion. In this report, we present a means to selectively inhibit a zinc finger transcription factor with cobalt(III) Schiff-base complexes. 1H NMR spectroscopy confirmed that the structure of a zinc finger peptide is disrupted by axial ligation of the cobalt(III) complex to the nitrogen of the imidazole ring of a histidine residue. Fluorescence studies reveal that the zinc ion is displaced from the model zinc finger peptide in the presence of the cobalt complex. In addition, gel-shift and filter-binding assays reveal that cobalt complexes inhibit binding of a complete zinc finger protein, human transcription factor Sp1, to its consensus sequence. Finally, a DNA-coupled conjugate of the cobalt complexes selectively inhibited Sp1 in the presence of several other transcription factors.
authors.affiliation: Division of Biology, Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: A Y
authors.initials: AY
authors.lastname: Louie
authors.forename: T J
authors.initials: TJ
authors.lastname: Meade
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D003035:Cobalt / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D016335:Zinc Fingers
chemical_list: D004268:DNA-Binding Proteins; D010455:Peptides; D003035:Cobalt