Electrochemical detection of wild type Saccharomyces cerevisiae responses to estrogens

The presence of an estrogen binding protein (EBP) and an endogenous ligand in three yeast species was first reported in 1982/1983. The ligand was shown to be 17β-estradiol and the binding affinities of EBP were demonstrated to be similar to those of rat estrogen receptors. This report describes detection of the behaviour of a putative estrogen binding protein in Saccharomyces cerevisiae using a double mediator electrochemical detection system. The response to estrogen is shown to be quantitative with signals detectable from 10−8 to 10−14 M. An incubation period of 5 h is established and a method to block electrochemical signals produced by the catabolism of exogenous substrates is demonstrated to be effective. The system provides a method that permits the use of wild type S. cerevisiae to quantify estrogens.