Dewald AH, Hodges JC, Columbus L. Biophysical Journal 100:2131 – 2140.
The spontaneous folding of two Neisseria outer membrane proteins, opacity-associated (Opa)60 and Opa50 into lipid vesicles was investigated by systematically varying bulk and membrane properties. Centrifugal fractionation coupled with sodium dodecyl sulfate polyacrylamide gel electrophoresis mobility assays enabled the discrimination of aggregate, unfolded membrane-associated, and folded membrane-inserted protein states as well as the influence of pH, ionic strength, membrane surface potential, lipid saturation, and urea on each. Protein aggregation was reduced with increasing lipid chain length, basic pH, low salt, the incorporation of negatively charged guest lipids, or by the addition of urea to the folding reaction. Insertion from the membrane-associated form was improved in shorter chain lipids, with more basic pH and low ionic strength; it is hindered by unsaturated or ether-linked lipids. The isolation of the physical determinants of insertion suggests that the membrane surface and dipole potentials are driving forces for outer membrane protein insertion and folding into lipid bilayers.
Jackie Hodges
Alison and Jackie’s paper #15 of the “Top 25 Hottest Articles” in Biophysical Journal
According to Science Direct, from April to June 2011
Physical Determinants of Beta-Barrel Membrane Protein Folding in Lipid Vesicles
Biophysical Journal, Volume 100, Issue 9, May 2011, Pages 2131-2140
Dewald, Alison H.; Hodges, Jacqueline C.; Columbus, L.
is 15th in the “Top 25 Hottest Articles” of Biophysical Journal.
Jackie recieves CSS and nanoSTAR research funds
Jackie (3rd year chemistry major at UVA) received a stipend from the College Science Scholar Program and the nanoSTAR Undergraduate Summer Research Fund to continue her studies on determining the binding interactions between Opa proteins and the human cognate receptors.
Jackie receive a Harrison Award
Jackie was one of twenty-four University of Virginia undergraduates that received Harrison Undergraduate Research Awards for independent research this summer. Her research focuses on quantifying the interaction between an Opa protein from Neisseria gonorrhoeae and the human heparan sulfate proteoglycan receptor in vitro using heparin, a known competitive inhibitor of the interaction.
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Alison and Jackie receive a UVA Double Hoo Fellowship
The University of Virginia has awarded eight “Double-’Hoo” research awards, which fund pairings of undergraduate and graduate students who collaborate on research projects. Each project is awarded up to $5,000 toward research expenses, as well as an additional $500 for the faculty mentor overseeing the project. Jackie, a second-year chemistry-biochemistry major, and Alison, a fourth-year Ph.D. candidate in the Department of Chemistry, will study proteins found in the outer membrane of bacterial pathogens to understand how these proteins infect and colonize human cells.
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Undergraduate Student – Fourth Year
Chemistry major with biochemistry focus
Distinguished Major Program
Jackie is studying the direct binding of OpaHS (Opa50) to heparansulfate proteoglycan receptors (HSPGs) using fluorescence techniques and heparin, a structural analog of HSPGs. She aims to confirm a selective interaction between this membrane protein and the host receptor and quantify the binding affinity. Further understanding of the intrinsic protein and receptor properties that determine this selectivity will enhance studies of the protein-triggered engulfment of the pathogens.
Jackie receives College Science Scholar Stipend
Jackie (1st year at UVA) will join the Columbus Lab this summer to begin research on the reconstitution of Opa protiens into lipid vesicles. She received a stipend from the College Science Scholar Program.