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Chemistry Lecture: Dr. Lea Vacca Michel

  • Time:

    2:30 p.m.
  • Date:

    Friday, March 1, 2013
  • Location:

    Peckham Hall, Room 012/014

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Assessing the Orientation of Vaccine Candidate P6 in Nontypable Haemophilus influenzae

Lea Vacca Michel, Ph.D. Assistant Professor School of Chemistry and Material Science Rochester Institute of Technology (RIT)

While the vast majority of outer membrane lipoproteins in Gram-negative bacteria are tethered to the membrane via an attached lipid moiety and oriented facing in toward the periplasmic space of the cell, several lipoproteins have been shown to be surface exposed. The outer membrane lipoprotein P6 from the Gram-negative pathogenic bacteria nontypable Haemophilus influenzae (NTHi) is surface exposed and a leading vaccine candidate for prevention of NTHi infections. We recently found that P6 is not a transmembrane protein as previously thought (Michel et al Vaccine 2011; 29:1624-1627). However, studies suggest that P6 interacts with the peptidoglycan layer inside of the cell and monoclonal antibodies outside of the cell. Thus, an apparent contradiction is presented. If P6 does not span the outer membrane, how can P6 interact with both intracellular and extracellular molecules? Results from our experiments suggest that P6 exhibits two orientations in NTHi. Only one other lipoprotein (Lpp from Escherichia coli) has been shown to exist in two orientations, making this an exciting and relatively novel discovery with important implications in biology.

Lea Vacca Michel received her B.A. in Physics and Math from Colgate University. She received her Ph.D. in Biophysics from the University of Rochester under the advisement of Dr. Kara Bren (Department of Chemistry) where she studied the structure, function, and dynamics of c-heme proteins using nuclear magnetic resonance (NMR) spectroscopy and other biochemical techniques. Lea completed a postdoc with Dr. Linda Nicholson at Cornell University where she used NMR spectroscopy to study the dynamics of a protein proposed to be involved in the onset of Alzheimer's disease.

Event Info

Sponsored By:
Department of Chemistry and Biochemistry
Contact Information:
Stephen Beecher, Ph.D. 585-389-2581
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