ABSTRACT
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 17beta-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 5h 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.
