February 13, 2009: Researchers from the Nano-Science Center at the University of Copenhagen and the National Center for Scientific Research in France have developed a general method to study membrane proteins that can be used to screen several thousand proteins. According to the researchers, the method will substantially cut down on the time it takes to develop useful drugs.
The research results are published in the scientific journal, Proceedings of the National Academy of Sciences in the US (PNAS).
Membrane proteins are located at the surface of cells and they have a very important role in the communication between the cells in our body. Defective membrane proteins are involved in diseases such as cancer, cardiovascular diseases and neurological diseases, just to mention at few. The researchers have developed a system, where they tie a tag to the protein that attach it to a surface and make it possible to investigate it in the laboratories.
Until now membrane proteins have been difficult to study when they are away from their natural environment in the cell, where there a belt of lipids surrounds them. This belt is essential for their survival and proper function.
“With our new method we can study membrane proteins faster and more accurate using less material than before,” researcher Karen Martinez of the University of Copenhagen said in a news release. “We are using a kind of swimsuit for the proteins called amphipols. The amphipol substitute for the lipids, surround the membrane protein, and make it soluble in water while keeping its function intact. We attach a tag to the amphipol that will assemble to a surface like a key-lock system. When we have attached the proteins to a surface they can be adapted to several measuring instruments.”
The researchers have tested their method on several different proteins and the results are very promising. When looking for new drugs, the researchers wants to study the interaction between membrane proteins and other molecules – e.g. potential drugs. It can also be used for the detection of virus, bacteria and parasites.
An antibody recognizes a membrane protein dressed in an amphipol “swimsuit” attached to a solid surface. (Photo by Delphine Charvolin)