title: Purification of an inhibitor of DNA photolyase with fluorescent spectra similar to those of the enzyme.
abstract: 1. The binding of DNA photolyase, the enzyme which uncouples cyclobutadipyrimidines in DNA upon illumination, to its substrate was enhanced by a substance isolated from acidified autolysates of baker's yeast. 2. This substance, referred to as activator, was partially purified by chloroform extraction, ion-exchange chromatography on Dowex 50 and DEAE-cellulose, and gel filtration on Sephadex G-10. Upon lyophilization and storage at -20 degrees C, it was converted to a potent inhibitor of enzyme binding to substrate. 3. The inhibitor appeared as a single band in two thin-layer chromatography systems and was detected by ultraviolet absorbance, fluorescence, and ninhydrin staining. 4. The similarity between the fluorescence spectra of the inhibitor and the enzyme suggested that the inhibitor was structurally analogous to a chromophore in the enzyme and that the activator from which the inhibitor was derived may be the active chromophore of the enzyme.
mesh_terms: D001681:Biological Assay; D002852:Chromatography, Ion Exchange; D004247:DNA / Q000528:radiation effects; D004260:DNA Repair; D004789:Enzyme Activation / Q000187:drug effects; D005656:Fungal Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D006193:Haemophilus influenzae / Q000378:metabolism; D008190:Lyases / Q000037:antagonists & inhibitors*; D011830:Radiation Effects; D012441:Saccharomyces cerevisiae / Q000032:analysis*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays
chemical_list: D005656:Fungal Proteins; D004247:DNA; D008190:Lyases