title: alpha-Synuclein enhances bioluminescent activity of firefly luciferase by facilitating luciferin localization.
abstract: alpha-Synuclein, the pathological component of Parkinson's disease, has been demonstrated to be highly interactive with various protein partners. alpha-Synuclein has been shown to exert a novel effect on the bioluminescence of firefly luciferase by stimulating the oxyluciferin formation from its substrate of luciferin, which results in a significant enhancement of the spike of flashing light via concomitant augmentation for both rapid rise and quick decay of the luminescence. Binding affinity between alpha-synuclein and luciferase was evaluated with K(d) of 8.1 microM based on a dose-dependent enhancement of the luciferase activity by alpha-synuclein. Kinetic analyses indicated that alpha-synuclein has facilitated luciferin localization to the luciferase by decreasing apparent K(m), which makes the maximum rate of bioluminescence no longer dependent upon ATP concentration. Catalytic consequences of the alpha-synuclein binding to luciferase have led to a delayed onset of the coenzyme A-mediated retardation of the quick decay of flashing light as well as a shift in the emission spectra of bioluminescence. Taken together, the novel effects of alpha-synuclein toward the bioluminescence of luciferase have been demonstrated to be initiated by the specific molecular interaction between the proteins which has influenced the substrate (luciferin) localization to the enzyme.
authors.affiliation: School of Chemical and Biological Engineering, College of Engineering, Seoul National University, Seoul 151-744, Korea.
authors.forename: Jehoon
authors.initials: J
authors.lastname: Kim
authors.forename: Chung Hee
authors.initials: CH
authors.lastname: Moon
authors.forename: Seunho
authors.initials: S
authors.lastname: Jung
authors.forename: Seung R
authors.initials: SR
authors.lastname: Paik
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D049454:Firefly Luciferin / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D049409:Luciferases, Firefly / Q000502:physiology*; D049449:Luminescence; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D051844:alpha-Synuclein / Q000502:physiology*
chemical_list: D011994:Recombinant Proteins; D051844:alpha-Synuclein; D049454:Firefly Luciferin; D000255:Adenosine Triphosphate; D049409:Luciferases, Firefly