Electron microscopy revealed the presence of rigid, rod-like brushy glycoprotein (sugar-containing compounds) -- 30 billionths of a meter long -- similar to natural cell-surface proteins. Interaction between cells occurs when these rods stand up from the membranes, a property whose control remains poorly understood.
The surprise, Parthasarathy said, was that the sugar-laden rods stood up like trees rising in a forest only for particular fluorescent probes, which represented just 2 percent of the molecule's weight.
The big issue that surfaced from the project -- funded by the U.S. Department of Energy, National Science Foundation and the Alfred P. Sloan Foundation -- was that the slightest trepidation of a molecule's structure affects its orientation, he said.
The goal, Parthasarathy said, may be to determine how to control the orientation of the brush-like forest through either chemical or optical measures to, in turn, control cell interaction. Such control of artificially produced molecules, he added, could have huge potential applications in the electronics industry.
Parthasarathy's UO team is now looking at DNA anchored to membranes to compare the findings and see if such on-off switching of the orientation of molecules may be possible.
"There are brush-like proteins at cell surfaces that are really important for such things as cellular interactions within the immune system," Parthasarathy said. "At the surface of every cell is a forest of molecules to induce interactions. These proteins need to rise from the forest. What allows them to stick up or lie down? We've really had a poor idea of what's going on. Knowing the genome and what proteins are there is crucially important, but that information in itself does not tell you anything about the answer to the question."
|Contact: Jim Barlow|
University of Oregon