Scientists alter membrane proteins to make them easier to study
About 30 percent of the proteins encoded by the human genome are membrane proteins — proteins that span the cell membrane so they can facilitate communication between cells and their environment. These molecules are critical for learning, seeing, and sensing odors, among many other functions. Despite the prevalence of these proteins, scientists have had difficulty studying their structures and functions because the membrane-bound portions are very hydrophobic, so they cannot be dissolved in water. This makes it much harder to do structural analyses, such as X-ray crystallography. In an advance that could make it easier to perform this type of structural study, MIT researchers have developed a way to make these proteins water-soluble by swapping some of their hydrophobic amino acids for hydrophilic ones. The technique is based on a code that is much simpler than previously developed methods for making these proteins soluble, which rely on computer algorithms that have to...