Synthesis of a Cytokinin Linked by a Spacer to Dexamethasone and Biotin: Conjugates to Detect Cytokinin-Binding Proteins.
Yeast cells expressing cDNA libraries have provided two new approaches to facilitate further identification of cytokinin-binding proteins and receptors. These are the yeast three hybrid (Y3H) system and fluorescence activated cell sorting (FACS). The Y3H system requires a synthetic hybrid ligand comprising an "anchor" moiety (e.g., dexamethasone) linked to a cytokinin via a spacer. In the yeast nucleus, this ligand by binding connects two fusion proteins leading to a reporter gene activation and detection and characterisation of cytokinin binding proteins. Herein is reported the first synthesis of dexamethasone-cytokinin ligands with a spacer linkage. This was attached to the purine ring of 6-benzylaminopurine (BAP) at positions 2, 8 or 9. To achieve this, dexamethasone was modified by periodate oxidation yielding a carboxylic group used for conjugation to the spacer by amide formation. Biotinyl derivatives of cytokinins for FACS included those synthesised by reaction of an activated ester of biotin with 8-(10-amino-decylamino) derivatives of BAP and BAP 9-riboside. Properties of the conjugates and some biological situations where they could be applicable are discussed briefly.
['Wang|You|Y|', 'Letham|David S|DS|', 'John|Peter C L|PC|', 'Zhang|Ren|R|']
D001593:Benzyl Compounds D001710:Biotin D003583:Cytokinins D003907:Dexamethasone D005434:Flow Cytometry D017930:Genes, Reporter D015394:Molecular Structure D011485:Protein Binding D011506:Proteins D011687:Purines D011993:Recombinant Fusion Proteins D020798:Two-Hybrid System Techniques
cytokinin-binding proteins yeast three hybrid 6-benzylaminopurine (BAP) BAP-biotin conjugates BAP-dexamethasone conjugates