title: Cytokinin-specific binding protein in etiolated mung bean seedlings.
abstract: We have found that a synthetic urea derivative, N-(2-chloro-4-pyridyl)-N'-phenylurea (4PU30, forchlorfenuron), has even higher cytokinin activity than N6-benzyladenine (BA). Using [3H]4PU30 (2.83 TBq/mmol) as a probe, we confirmed chromatographically the presence of a high-affinity cytokinin-specific binding protein (CSBP) in whole-cell extract from etiolated mung bean seedlings. The apparent molecular weight of CSBP was estimated to be 21 kDa. The association constants (Ka's) of CSBP for 4PU30 and BA were calculated to be 4 x 10(10) M-1 and 3 x 10(9) M-1, respectively. Various active cytokinins showed mutually competitive binding to CSBP, and their affinities for CSBP corresponded well to their cytokinin activities at the tissue level.
authors: Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
authors: R
authors: R
authors: Nagata
authors: E
authors: E
authors: Kawachi
authors: Y
authors: Y
authors: Hashimoto
authors: K
authors: K
authors: Shudo
mesh_terms: D029681:Arabidopsis Proteins; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002478:Cells, Cultured; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003583:Cytokinins / Q000378:metabolism*; D007887:Fabaceae; D008024:Ligands; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D010946:Plants, Medicinal
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D003583:Cytokinins; D008024:Ligands; D010940:Plant Proteins