title: [Inhibitory effect and kinetic analysis of sodium quercetin-7,4'-disulphate on recombinant human protein kinase CK2 holoenzyme].
abstract: OBJECTIVE
  To study the direct effect and kinetics of sodium quercetin-7,4'-disulphate (SQDS) on recombinant human protein kinase CK2 holoenzyme.
  
  
  METHODS
  The recombinant human CK2 holoenzyme activity was assayed by detecting incorporation of 32P of [gamma-32P] ATP into the substrate in various conditions.
  
  
  RESULTS
  The recombinant human CK2 was a second messenger (Ca2+, cAMP and cGMP) independent protein kinase. The characterization and function of the reconstituted holoenzyme were consistent with those of native CK2. SQDS was shown to strongly inhibit the holoenzyme activity of recombinant human protein kinase CK2 with an IC50 of 4.4 mumol.L-1, which was more effective than DRB and A3, known CK2 special inhibitors. Kinetic studies of SQDS on recombinant human CK2 showed: the inhibition was competitive with ATP and noncompetitive with casein.
  
  
  CONCLUSIONS
  SQDS is a potent inhibitor of protein kinase CK2. This study provide experimental basis for the development of more effective inhibitors of CK2 and for clinical application of SQDS in the future.
authors.affiliation: Institute of Biochemistry and Molecular Biology, Guangdong Medical College, Zhanjiang 524023, China. xgliu@gdmc.edu.cn
authors.forename: Xin-guang
authors.initials: XG
authors.lastname: Liu
authors.forename: Nian-ci
authors.initials: NC
authors.lastname: Liang
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.forename: Ji
authors.initials: J
authors.lastname: She
authors.forename: Li-er
authors.initials: LE
authors.lastname: Mo
mesh_terms: D047390:Casein Kinase II; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011794:Quercetin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; C437392:disodium quercetin-7,4'-disulfate; D004004:Dichlororibofuranosylbenzimidazole; D011794:Quercetin; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases