Novel Amphiphilic Molecules Mediate Membrane Protein Crystal Contacts

Abstract

There have been quite a few approaches developed over the last two decades towards the creation of structurally novel amphiphiles. Some of these reagents have found broad applications in membrane protein biochemistry, being used for the solubilization and stabilization of membrane proteins for functional studies. However, success has been very limited in using these novel amphiphiles to crystallize IMPs. The lack of success exemplifies the significant degree of challenge and makes it clear that other types of amphiphiles are needed. We have contributed hundreds of new detergents through our previous efforts in this area. These detergents have been tested for various purposes (e.g. solubilization, stabilization, NMR, crystallization), and several were found to perform as well or better than the most popular commercial detergents. In particular, the use of our newly designed cholesterol-like facial amphiphiles has facilitated the 3D crystallization and structural determination of several membrane proteins. Interestingly, we have found evidence that facial amphiphiles mediated protein crystal contact. These results open up the possibility for future investigations of using intelligently designed stabilization reagents to mediate membrane protein surface interactions so as to increase crystallization propensity and improve crystal diffraction.