부산대학교 도서관

CK2 is a pleiotropic, constitutively active protein kinase responsible for the phosphorylation of more than 300 physiological substrates. Typically, this enzyme is found in tetrameric form consisting of two regulatory subunits CK2[beta] and two catalytic subunits CK2[alpha] or CK2[alpha]'. Several natural occurring flavonoids were tested for their ability to inhibit both CK2 holoenzymes, CK2[alpha].sub.2[beta].sub.2 and CK2[alpha]'.sub.2[beta].sub.2. We identified few substances selectively inhibiting only the [alpha]' subunit. Other compounds showed similar effect towards all four isoforms. In some cases, like chrysoeriol, pedalitin, apigenin, and luteolin, the [alpha].sub.2[beta].sub.2 holoenzyme was at least six times better inhibited than the free [alpha] subunit. Otherwise, we have found a luteolin derivative decreased the kinase activity of CK2[alpha]' with an IC.sub.50 value of 0.8 [mu]M, but the holoenzyme only with 9.5 [micro]M.
Author(s): Andrea Baier [sup.1] , Jolanta Nazaruk [sup.2] , Anna Galicka [sup.3] , Ryszard Szyszka [sup.1] Author Affiliations: (Aff1) 0000 0001 0664 8391, grid.37179.3b, Department of Molecular Biology, The John [...]