Scientists Develop New Surface Patterning Method for Carb Chip

Newswise — Although the application of microarray chip technology to the study of carbohydrates is relatively new, it holds great promise for disease detection and vaccine development in animals and humans.

A research team led by Nicola Pohl, an assistant professor of chemistry at Iowa State University, has developed a new surface patterning method to make carbohydrate chips for bioscreening.

"The success of DNA and protein microarrays in chip format for biosample screening using small sample volumes has led to a variety of technologies that diagnose many diseases," Pohl said. "Extending this concept to other biomolecules has been challenging."

The new method developed by Pohl and graduate students Kwang-Seuk and Firoz Jaipuri is based on a fluorous Teflon®-pan like surface interacting with fluorous-tagged compounds. Unlike most other molecules, these fluorous-tailed sugars stick to the Teflon-type surface, which allows the tagged carbohydrates to be immobilized in a microarray format on standard glass microscope slides.

"The surprising part was that this fluorous interaction was strong enough to allow standard bioassays on the chips without rinsing away the sugars," Pohl said.

The Teflon-like tail also can be used to speed up the synthesis of complex carbohydrates. The fluorous-based microarray method should rival the speed and ease of solid-phase synthesis currently used for the commercial production of DNA and peptides, Pohl said.

"It will allow a whole range of carbohydrate chips to be produced, including chips that contain sugars of particular interest to plant scientists," said Pohl, a researcher associated with Iowa State's Plant Sciences Institute.

The method should also work with other molecules, such as peptides, on the same chip to screen for antibodies correlated with diseases such as bacterial or fungal infections and diseases with known biomarkers (molecular indicators) such as cancer. And the new chips can help screen new biocatalysts that act on carbohydrates and discover new proteins, such as plant lectins, that bind to specific carbohydrate sequences.

The researchers' initial work demonstrating the fluorous-based carbohydrate chip method was published in the Sept. 2 online edition of the Journal of the American Chemical Society. The research showed how two plant proteins (from jack beans and a bushy plant) only bind to specific sugar structures.

"The same principle can be used to screen for antibodies that bind to certain sugar structures on pathogens to let us know that that person or animal has come in contact with the pathogen and to let us know which carbohydrates the person or animal generates an immune response against in order to develop carbohydrate-based human and animal vaccines," Pohl said.