Characterization and localization of fusicoccin-binding sites in leaf tissues of Vicia faba L. probed with a novel radioligand

摘要: Tritiated 9′-nor-fusicoccin-8′-alcohol provides a highly bioactive radioligand of high specific activity which is easily prepared by oxidation fusicoccin and subsequent reduction with tritiated sodium borohydride. Using this radioligand, we have identified characterized selective binding site for (Ka [3H]-9′-nor-fusicoccin-8′-alcohol=0.20·109 M-1; Ka, apparent fusicoccin=0.21·109 M-1) located at the plasmalemma Vicia faba leaf tissue. The thermolabile, readily degraded trypsin apoplastic face based on results obtained using right-side-out vesicles aqueous two-phase partitioning macromolecular fusicoccin-derivatives. binding-protein present in guard cells faba, as shown use purified guard-cell protoplasts.