New sensors streamline detection of estrogenic compounds

Aug 25, 2011

Researchers have engineered new sensors that fluoresce in the presence of compounds that interact with estrogen receptors in human cells. The sensors detect natural or human-made substances that alter estrogenic signaling in the body.

The study appears in the journal Biotechnology and Bioengineering.

Estrogen occurs naturally in the body (in the form of 17-beta-estradiol), and a variety of plants (such as soybeans), pharmaceuticals, microbial and (such as bisphenol A, in plastics) are also known to activate or block the activation of estrogen receptors in .

"There are so many estrogenic compounds in our environment, and some of them could be a danger to health," said University of Illinois chemical and biomolecular engineering professor Huimin Zhao, who led the research. Zhao also is an affiliate of the chemistry and biochemistry departments, the Center for Biophysics and , and the Institute for Genomic Biology, all at Illinois. "We are concerned about estrogenic compounds because they interact with the estrogen receptor, which plays an important role in many important biological processes, like reproduction, , and metabolism."

The estrogen receptor is also implicated in a majority of breast cancers, he said, with compounds that activate it potentially spurring the growth of .

The researchers used part of the itself in the design of their new sensors. They took the region of the receptor that binds to estrogenic compounds (called the "ligand-binding domain) and added two halves of a fluorescent protein that glows only when the halves are reunited. The ligand-binding domain changes its conformation when it binds to an estrogenic compound. This change, the researchers hoped, would draw the two parts of the fluorescent protein together to produce a signal.

In a series of trials, the researchers found that two of their sensors reliably signaled the presence of estrogenic compounds. The first, "sensor 2," differentiated between compounds that activate and those that block estrogen receptors, glowing more brightly in the presence of one and dimming when bound to the other. A second bioengineered molecule, "sensor 6," fluoresced in the presence of both types of compounds, making it a reliable indicator of chemicals that bind to the receptor.

When incubated in human cells, the sensors responded to estrogenic compounds within a few hours, Zhao said, with the fluorescent signals gradually increasing in strength up to 24 hours. "And also the sensitivity is pretty high," he said. "Of course it depends on the compound that you're testing; different compounds will have different affinities. But for a truly estrogenic compound, we can detect at the nanomolar level, a very low level."

These are the first such sensors to work in human cells without costly additional chemical steps, he said.

The new sensors will help researchers and clinicians quickly and efficiently determine whether a food, drug or chemical substance interacts with estrogen receptors in human cells, Zhao said.

Explore further: Study identifies highly efficient new Cas9 for in vivo genome editing

More information: "A New Fluorescence Complementation Biosensor for Detection of Estrogenic Compounds," onlinelibrary.wiley.com/doi/10… 2/bit.23254/abstract

Related Stories

Researchers improve design of genetic on-off switches

Apr 07, 2005

Researchers at the University of Illinois at Urbana-Champaign have set a new standard in the design and engineering of nuclear hormone receptor-based genetic on-off switches, without causing new problems or aggravating existing ...

Recommended for you

Longer DNA fragments reveal rare species diversity

10 hours ago

A challenge in metagenomics is that the more commonly used sequencing machines generate data in short lengths, while short-read assemblers may not be able to distinguish among multiple occurrences of the ...

Simplifying SNP discovery in the cotton genome

13 hours ago

The term "single-nucleotide polymorphism" (SNP) refers to a single base change in DNA sequence between two individuals. SNPs are the most common type of genetic variation in plant and animal genomes and are, thus, an important ...

Japanese company 'makes tear-free onions'

Mar 31, 2015

The sobbing of a chef as he chops onions in the kitchen could be a thing of the past thanks to one Japanese company which says it has produced a tear-free vegetable.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.