George Rayfield's research area is membrane biophysics. The structure, interaction, and function of biologically relevant molecules is studied by using a variety of physical techniques. Two major research projects are under way -- one deals with the functional transport characteristic of membrane proteins (particularly bacteriorhodopsin) and the other with the study of molecular monolayers.
A particular light-activated proton pump, bacteriorhodopsin, provides investigators with an ideal system for study. Due to certain characteristics of this system, detailed knowledge about its molecular structure is emerging. Moreover, it is possible to obtain unique experimental data relevant to its functional properties. It is generally felt that there are basic structural functions common to many active pumps. Therefore, although this protein is of intrinsic interest in itself, it will probably yield clues necessary to unravel the general molecular process of active membrane transport.
Interactions between larger organic molecules are beginning to be studied at the molecular level by using statistical mechanics. Lipid-lipid and lipid-protein interactions are thought to play a significant role in the biological function of the cell wall. The lipid molecules that make up the cell wall are in a highly condensed state, so a theoretical study of their interactions is a formidable problem. Two-dimensional molecular monolayers (in a Langmuir trough) represent an ideal test system for these theories, because certain experimental parameters can be altered in a controlled way. Experimental studies of these systems' two-dimensional equations of state yield valuable information directly relevant to the theorecially derived partition functions. A sophisticated computer-controlled apparatus has been developed to make these measurements.