Open AccessFluorescent anticytokinins as a probe for binding
Author(s) -
HAMAGUCHI Nobuko,
IWAMURA Hajime,
FUJITA Toshio
Publication year - 1985
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1985.tb09338.x
Subject(s) - chemistry , ligand binding assay , fluorescence , binding site , ribosome , biochemistry , pyrimidine , ligand (biochemistry) , receptor , biological activity , biophysics , in vitro , biology , rna , physics , quantum mechanics , gene
4‐Substituted 2‐methylthiopyrido[2,3‐ d ]pyrimidines, a series of recently developed anticytokinins, have been found in fluoresce strongly in water and to be useful as probes for binding studies. The binding activity of the soluble proteins and particulate fraction of tobacco callus cells to the biologically most active member of the family, 4‐ n ‐butylamino‐2‐methylthiopyrido[2,3‐ d ]pyrimidine (BAMPP), was studied fluorimetrically. We found that the binding activity is better monitored in terms of saturable binding rather than in terms of the amount of bound ligand, a conventional method used in isolation studies of hormone receptor proteins. Using this technique we isolated two kinds of high‐affinity cytokinin‐binding proteins from the soluble fraction and identified a high‐affinity binding site on ribosomes.