title: Aequorin variants with improved bioluminescence properties.
abstract: The photoprotein aequorin has been widely used as a bioluminescent label in immunoassays, for the determination of calcium concentrations in vivo, and as a reporter in cellular imaging. It is composed of apoaequorin (189 amino acid residues), the imidazopyrazine chromophore coelenterazine and molecular oxygen. The emission characteristics of aequorin can be changed by rational design of the protein to introduce mutations in its structure, as well as by substituting different coelenterazine analogues to yield semi-synthetic aequorins. Variants of aequorin were created by mutating residues His16, Met19, Tyr82, Trp86, Trp108, Phe113 and Tyr132. Forty-two aequorin mutants were prepared and combined with 10 different coelenterazine analogues in a search for proteins with different emission wavelengths, altered decay kinetics and improved stability. This spectral tuning strategy resulted in semi-synthetic photoprotein mutants with significantly altered bioluminescent properties.
authors.affiliation: Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA.
authors.forename: E
authors.initials: E
authors.lastname: Dikici
authors.forename: X
authors.initials: X
authors.lastname: Qu
authors.forename: L
authors.initials: L
authors.lastname: Rowe
authors.forename: L
authors.initials: L
authors.lastname: Millner
authors.forename: C
authors.initials: C
authors.lastname: Logue
authors.forename: S K
authors.initials: SK
authors.lastname: Deo
authors.forename: M
authors.initials: M
authors.lastname: Ensor
authors.forename: S
authors.initials: S
authors.lastname: Daunert
mesh_terms: D000331:Aequorin / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D001059:Apoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001407:Bacillus / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D007093:Imidazoles / Q000737:chemistry / Q000378:metabolism; D049408:Luminescent Agents / Q000737:chemistry / Q000378:metabolism; D008164:Luminescent Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010100:Oxygen / Q000378:metabolism; D055550:Protein Stability; D011719:Pyrazines / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D001059:Apoproteins; D007093:Imidazoles; D049408:Luminescent Agents; D008164:Luminescent Proteins; D011719:Pyrazines; D011994:Recombinant Proteins; C060014:apoaequorin; C017144:coelenterazine; D000331:Aequorin; D010100:Oxygen