Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Photonoic Crystal Biosensors Detect Protein-DNA Interactions

24.09.2008
Scientists at the University of Illinois have developed a new class of disposable, microplate-based optical biosensors capable of detecting protein-DNA interactions.

Based on the properties of photonic crystals, the biosensors are suitable for the rapid identification of inhibitors of protein-nucleic acid and protein-protein interactions.

“Protein-DNA interactions are essential for fundamental cellular processes such as transcription, DNA damage repair and apoptosis,” said Paul Hergenrother, a professor of chemistry and an affiliate of the university’s Institute for Genomic Biology. “Screening for compounds that inhibit particular kinds of protein-DNA binding is a very important step in drug development.”

Developed by Brian Cunningham, a U. of I. professor of electrical and computer engineering, the photonic crystal biosensors consist of a low-refractive-index polymer grating coated with a film of high-refractive-index titanium oxide, attached to the bottom of a standard 384-well microplate. Each well functions as a tiny test tube with a biosensor in the bottom.

“First, we selectively attach a biomolecule, such as DNA, to the bottom of each well. Then we see how that biomolecule interacts with other molecules, including drugs,” said Cunningham, who also is affiliated with the university’s Beckman Institute, Micro and Nanotechnology Laboratory, and Institute for Genomic Biology.

By examining the light reflected from the photonic crystal, the researchers can tell when molecules are added to, or removed from, the crystal surface. The measurement technique can be used, for example, in a high-throughput screening mode to rapidly identify molecules and compounds that prevent DNA-protein binding.

The researchers demonstrated the new technology by examining two very different protein-DNA interactions. The first was the bacterial toxin-antitoxin system MazEF, which binds to DNA in a sequence-specific manner and is thought to be responsible for the maintenance of resistance-encoding plasmids in certain infectious bacteria. The second was the human apoptosis-inducing factor (AIF), a protein that binds to chromosomal DNA in a DNA-sequence-independent manner.

The photonic crystal biosensor technology was further utilized in a screen for inhibitors of the AIF-DNA interaction, and through this screen aurin tricarboxylic acid was identified as the first in vitro inhibitor of AIF.

“Aurin tricarboxylic acid displayed about 80 percent inhibition of AIF-DNA binding,” Hergenrother said. “Aurin tricarboxylic acid was the only compound to exhibit significant inhibition out of approximately 1,000 compounds screened.”

While the photonic crystal biosensor was demonstrated only for protein-DNA interactions, analogous experiments with protein-RNA interactions, and protein-protein interactions are also possible, Cunningham said. “We also could grow cancer cells on the photonic crystal surface, and see how different drugs affect cell growth.”

The researchers describe their work in the journal ACS Chemical Biology. With Cunningham and Hergenrother, the paper’s co-authors are graduate student and lead author Leo Chan, and graduate students Maria Pineda and James Heeres.

The work was funded by the National Institutes of Health.

Editor’s note: To reach Brian Cunningham, call 217-265-6291; bcunning@illinois.edu

James E. Kloeppel | University of Illinois
Further information:
http://www.illinois.edu

More articles from Physics and Astronomy:

nachricht Smallest transistor worldwide switches current with a single atom in solid electrolyte
17.08.2018 | Karlsruher Institut für Technologie (KIT)

nachricht Protecting the power grid: Advanced plasma switch for more efficient transmission
17.08.2018 | DOE/Princeton Plasma Physics Laboratory

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>