Zhang Youyi

Revealing binding interaction between seven drugs and immobilized β2-adrenoceptor by high-performance affinity chromatography using frontal analysis.

The development of new approaches to study the affinity between ligands and G‐protein‐coupled receptors proves to be of growing interest for pharmacologists, chemists, and biologists. The aim of this work was to determine the binding of seven drugs to β2‐adrenoceptors by frontal analysis using immobilized receptor stationary phase. The dissociation constants (Kd) were determined to be (3.16 ± 0.09) × 10−4 M for salbutamol, (4.29 ± 0.12) × 10−4 M for terbutaline, (6.19 ± 0.16) × 10−4 M for methoxyphenamine, (2.11 ± 0.07) × 10−4 M for tulobuterol, (1.82 ± 0.11) × 10−4 M for fenoterol, (9.75 ± 0.24) × 10−6 M formoterol, and (9.84 ± 0.26) × 10−5 M for clenbuterol. These results showed a good correlation with the data determined by radioligand binding assay. Further investigations revealed that the dissociation constant mainly attributed to the number of hydrogen bonds in the structures of ligands. This study indicates that affinity chromatography using immobilized receptor stationary phase can be used for the direct determination of drug‐receptor binding interactions and has the potential to become a reliable alternative for quantitative studies of ligand–receptor interactions. Copyright

Chromatography studies on bioaffinity of nine ligands of α1 adrenoceptor to α1D subtypes overexpressed in cell membrane

To improve selectivity and specificity of cell membrane chromatography (CMC), the chromatography affinities of nine ligands of α1-adrenergic receptor(AR)to α1D-AR subtype were investigated. The human embryonic kidney (HEK) 293 cells expressed by cDNA of α1D-AR subtypes were cultured and cell membrane stationary phase (CMSP) was prepared. Then the interactions between ligands and α1D-AR in CMSP were investigated using CMC. The affinity rank order to α1D-AR subtype obtained from CMC for the nine α1-adrenoceceptor ligands is: prazosin, BMY7378, phentolamine, oxymetazoline, 5-methylurapidil, norepinephrine, phenylephrine, methoxamine, RS-17053. The affinity rank order is similar and correlates well with that obtained from others’ radioligand binding assays (RBA). CMSP prepared by transfected HEK293 cells with α1D-adrenoceptor cDNA and CMC method could be used to evaluate affinities of drug-receptor and drug-receptor subtypes and to screen drugs selective to α1D-AR.