Nicole Pike
Staff Writer

William Dowhan, Ph.D., of the University of Texas Medical School in Houston, led a seminar this week on lipid-protein interactions as determinants of protein structure and function. Dowhan said lipids research is “the area to be in.” He should know, considering that he and his colleagues have made some of the most renowned breakthroughs in understanding how lipids function and how they interact with protein membranes.
Dowhan has a doctorate in biochemistry and molecular biology from the University of California at Berkeley and was a postdoctoral fellow at Harvard Medical School. He and his team recognized the diversity and challenges of functions of membrane lipids. From there, they discovered that lipids provide the solvent in which membrane proteins fold; likewise, lipids support and influence membrane associative functions. They also provide precursors for molecular synthesis and act as molecular signals in cell regulation.
The challenges that arise when studying the functions of lipids deal with them having no inherent catalytic activity. In addition, it is not always clear how to relate their in vitro properties to their in vivo function. Another issue involves the problem of lipids not being encoded by genes. When trying to combat this problem, Dowhan explained that genetic manipulation of lipid synthesis has global effects; therefore, a broad biochemical and molecular approach must be used.
Dowhan began a molecular genetic and biochemical approach in the early 90s to investigate polar lipid function. “Designer strains” of E. coli and yeast were developed with altered membrane lipid composition. They were used as “biological reagents” to correlate membrane lipid compatibility with phenotypes. Dowhan states that, “the important outcome of this study” is that final topology is established by protein-lipid interactions rather than only the translation.
Beth Mullin, a professor of biochemistry, cellular and molecular biology at the University of Tennessee, says that Dowhan’s research is “applicable to all living organisms.” What Dowhan and his colleagues have discovered about lipid-protein interactions directly relates to nutrition and health. Lipids are fats that are generally considered bad to any diet fanatic, but, as any health-conscious person knows, some fats are extremely healthy. Jeff Becker, the department head of microbiology at UT, said that “lipids help the membrane proteins fold correctly.” Without the good fats, our bodies could not properly make use of the proteins we put into them.
Dowhan’s seminar was just one of many being offered by the Department of Biochemistry and Cellular and Molecular Biology. The seminar series is a semester-long course being offered to graduate students, but enrollment is not required to attend. For more information on future speakers and topics, go to the BCMB’s Web site, http://www.bio.utk.edu/bcmb/.