Mazelike course sorts membrane proteins

Abstract

Two Stanford University researchers have demonstrated a fundamentally new approach for separating biomolecules such as the proteins found in cell membranes. method can separate these lipid-soluble molecules in a membranelike environment and can do it continuously, unlike separation methods that work in batches [ Science , 285 , 1046 (1999)] The ability to separate membrane-associated molecules is extremely important because they play a vital role in the life of the cell and have proven exceptionally difficult to purify, characterize, and study, says Stanford chemistry professor Steven G. Boxer. To demonstrate the new approach, Boxer and postdoctoral associate Alexander van Oudenaarden built a device called a two-dimensional geometrical Brownian ratchet. Such a device is discussed in several theoretical papers published recently by physicists. ratchet is basically a mazelike obstacle course that the molecules to be separated must stumble through under the competing influences of an electric field...