New Bacteria Aid in Hazard Detection, Drug Discovery

Researchers in chemical and biomolecular engineering are developing completely new methods for engineering bacteria that can detect and identify hormone-like drugs and pollutants.

David W. Wood, associate professor, and his colleagues create complex new proteins and enzymes by combining functional pieces of proteins and enzymes found in nature.

For example, the estrogen hormone receptor protein in human cells is involved in vital life functions such as development, reproduction and metabolism, and many drug treatments for various illnesses target this receptor. However, hormone receptors also are affected by natural and synthetic hormone-like chemicals, and these interactions have been connected to breast cancer, decreased fertility and other disorders. One of these chemicals is BPA, which leaches from some types of plastics and has been blamed for adverse health effects in humans.

Detecting and identifying chemicals that interact with the human estrogen receptor proteins is important in the medical field, but most existing methods for accomplishing this are complex and expensive and often involve animals.

Wood and fellow engineers have created a simple method for detecting hormone-like compounds by combining the human estrogen receptor protein with an enzyme found in E. coli. The resulting chimera protein is then made by these simple bacterial cells, which causes them to react to the presence of hormone-like chemicals by changing their growth rate. Thus, the researchers can use these cells as biosensors to detect estrogenic chemicals.

Because these biosensing bacteria are simple and relatively inexpensive to create, researchers can use them for a wide variety of applications to determine whether a given chemical is affecting an important hormone target. Further, these bacterial cells are much easier to use than animal models. Wood’s team has now made bacteria with the estrogen receptors of several animals and with several other human hormone receptors. The researchers’ goal is to use this general approach to create new methods for identifying hazards in industrial and environmental chemicals and to find new hormone-like drugs for humans and animals.