Properties of a high-affinity cytokinin-binding protein from wheat germ

✍ Scribed by Gideon M. Polya; Andrew W. Davis

• Book ID: 104750573
• Publisher: Springer-Verlag
• Year: 1978
• Tongue: English
• Weight: 851 KB
• Volume: 139
• Category: Article
• ISSN: 0032-0935
• DOI: 10.1007/bf00387139

✦ Synopsis

A soluble protein that interacts with a range of cytokinins was extensively purified from wheat (Triticum aestivum L.) germ. This protein has a Ke for kinetin of 2• 10 -7 M. The binding of kinetin to the protein is inhibited by low concentrations of synthetic and naturally-occurring cytokinins including N6-benzyladenine, N6-benzyladenosine, kinetin riboside, N6-dimethylallyladenine, N6-dimethylallyladenosine, zeatin, zeatin riboside, N6-dimethyladenine and N6-dimethyladenosine. Adenine, adenosine and several non-N6-substituted adenine derivatives were ineffective as inhibitors of kinetin binding. While N 6butyryl-3',5'-eyclic AMP, N6,2-O'-dibutyryl-3',5'-cyclic AMP and 2',3'-cyclic AMP inhibited binding of kinetin to the protein, 3',5"-cyclic AMP was ineffective. The kinetin-binding protein is heat-labile and pronase-sensitive. Kinetin-binding activity exactly cochromatographs with a single peak of carbohydrate and protein on gel-filtration and is displaced from concanavalin A-Sepharose 4B by e-methylglucoside. On gel filtration, the kinetin-binding protein behaves as a soluble protein with an apparent molecular weight of 180,000 daltons.