title: Anti-microtubule 'plinabulin' chemical probe KPU-244-B3 labeled both alpha- and beta-tubulin.
abstract: Plinabulin (1, NPI-2358), a potent microtubule-targeting agent derived from the natural diketopiperazine 'phenylahistin' with a colchicine-like tubulin depolymerization activity, is an anticancer agent undergoing Phase II clinical trials in four countries including the United States. In order to understand the precise binding mode of plinabulin with tubulin, a new bioactive biotin-tagged photoaffinity probe 4 (KPU-244-B3) was designed and synthesized. Probe 4 showed significant binding affinity to tubulin in a binding assay, and selectively bound to tubulin in an HT-1080 cell lysate without photo-irradiation. In a tubulin photoaffinity labeling study, probe 4 labeled both alpha- and beta-tubulin subunits and these interactions were competitively inhibited by plinabulin during photo-irradiation. These results suggest that plinabulin binds in the boundary region between alpha- and beta-tubulin near the colchicine binding site, and not inside the colchicine binding cavity.
authors.affiliation: Department of Medicinal Chemistry, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Makiko
authors.initials: M
authors.lastname: Sumikura
authors.forename: Koushi
authors.initials: K
authors.lastname: Hidaka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yasui
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kiso
authors.forename: Fumika
authors.initials: F
authors.lastname: Yakushiji
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hayashi
mesh_terms: D001667:Binding, Competitive; D015153:Blotting, Western; D045744:Cell Line, Tumor; D054659:Diketopiperazines; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007093:Imidazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D019920:Photoaffinity Labels / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D010879:Piperazines / Q000737:chemistry / Q000494:pharmacology*; D010880:Piperidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D014404:Tubulin / Q000737:chemistry* / Q000187:drug effects
chemical_list: D054659:Diketopiperazines; D007093:Imidazoles; C551970:KPU-244-B3; C514351:NPI 2358; D019920:Photoaffinity Labels; D010879:Piperazines; D010880:Piperidines; D014404:Tubulin