Discovery of key protein's shape could lead to improved bacterial pneumon...( s. Our work confirmed that the pn...),Health

"Our work confirmed that the pneumococcus uses CbpA to bind to human cells," said Beth Mann, a research laboratory specialist in Tuomanen's lab who developed the bacteria carrying mutated CbpA. Mann, co-author of the paper, also showed that the long, paddle-shaped extensions of the protein must be folded in a specific way in order for CbpA to work.

The discovery of the actual shape of CbpA was made using nuclear magnetic resonance (NMR) spectroscopy and circular dishroism (CD). NMR combines radio wave emissions and a powerful magnetic field to determine the structure of proteins suspended in solutions, while CD measures differences in the absorption of different types of polarized light by molecules to determine their shape. It also can show how that shape can change when the protein interacts with another molecule. "This work required that we develop new NMR methods in order to determine the shape of this protein, which undergoes changes as it interacts with pIgR," said Rensheng Luo, Ph.D., a post-doctoral fellow in St. Jude Structural Biology and Infectious Diseases and first author of the paper.

Other authors of the paper are William S. Lewis, Richard Heath, Siva Sivakolundu, Eilyn R. Lacy (St. Jude); Arthur Rowe (University of Nottingham, Leicestershire, UK); Agnes E. Hamburger (California Institute of Technology, Pasadena, Calif.) and Pamela J. Bjorkman (Howard Hughes Medical Institute, California Institute of Technology).

'"/>

Contact: Bonnie Cameron
bonnie.cameron@stjude.org
901-495-4815
St. Jude Children's Research Hospital
21-Dec-2004