When Dr. McConnell moved to Stanford University in 1964, he began to use the methods of physical chemistry to study biological problems. There, he introduced a method called spin labels, in which electron and NMR spectra are used to study the structure and kinetics of proteins and lipids. His work showed how to measure the movement of molecules through and within membranes in the laboratory; this was later shown by many researchers to apply to living cell membranes. His research also showed how a protein present in the body combines with that of a foreign peptide on the cell membrane to enable the body to recognize a pathogenic invader.
Some of these discoveries are critical to understanding many properties of membranes, says Dr. McConnell, and a large portion of biology takes place in and on membranes, so understanding them is crucial.
Dr. McConnells recent work has focused on the behavior of cholesterol in membranes. Discoveries by his team concerning the properties of monomolecular films on the surface of water have shed light on cholesterol-phospholipid interactions that previously had puzzled scientists in several different fields of research.
Cholesterol forms special condensed complexes, says Dr. McConnell. By describing them mathematically, one can predict many of the properties that have been observed regarding cholesterol and phospholipid mixtures, which are major components of animal cell membranes. He believes th
Contact: Melissa Quiroz
The Welch Foundation