Analytical Sciences

Abstract − Analytical Sciences, 19(10), 1355 (2003).

Piezo Electric Sensor for Endocrine-Disrupting ChemicalsUsing Receptor-co-factor Interaction
Masaharu MURATA,*  Chifumi GOUDA,* Kentaro YANO,* Shinichiro KUROKI,* Tatsuo SUZUTANI,** and Yoshiki KATAYAMA*
*Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan
**Department of Microbiology, School of Medicine, Fukushima Medical University, 1 Hikarigaoka, Fukushima 960-1295, Japan
In vitro screening assays are useful techniques for the determination of receptor-mediated activities in environmental samples. In order to define whether environmental chemicals act as an agonist or antagonist to the human estrogen receptor (hER), we have constructed a biosensor based on ligand-inducible interactions between hER and relative proteins on a quartz crystal microbalance (QCM). The his-tagged proteins, which were expressed in E. coli by recombinant DNA technology, were immobilized on an Au-electrode with Ni(II)-mediated chemisorption using the histidine tag and thiol-modified iminodiacetic acid. The resonance-frequency change of the protein-modified electrode was caused by association or dissociation with the hER relative proteins on the surface in the presence of estrogen. These results suggest that this sensor is applicable as a large-scale screening tool for estrogenic compounds.