| Start Date: | 10/30/2014 | Start Time: | 4:30 PM |
| End Date: | 10/30/2014 | End Time: | 5:30 PM |
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Event Description
Ekaterina V. Pletneva, PhD,
Department of Chemistry, Dartmouth College
"Becoming a peroxidase: conformational dynamics of a membrane-bound cytochrome c"
Interactions of cytochrome c (cyt c) with a mitochondrial membrane cardiolipin (CL) are important for both electron transfer and apoptotic functions of this protein. A sluggish peroxidase in its native state, when bound to CL, cyt c catalyzes CL peroxidation, which contributes to the protein apoptotic release. The details of the cyt c-CL interactions, however, are not clear, even more in living systems. The heterogeneous CL-bound cyt c ensemble is difficult to characterize with traditional structural methods and ensemble-averaged probes. We have employed time-resolved FRET measurements and fluorescence correlation spectroscopy (FCS) to evaluate structural properties of the CL-bound protein in dye-labeled variants of cyt c. Dye-to-heme distance distributions reveal a conformational diversity of the CL-bound cyt c ensemble with distinct populations of the polypeptide structures that vary in their degree of protein unfolding. A fraction of the ensemble is substantially unfolded; these largely open cyt c structures likely dominate the peroxidase activity of the CL-bound cyt c ensemble. We analyze the sequence of the protein unfolding events and effects of physiological modulators on the cyt c ensemble. Experiments with biological membranes test the developed mechanistic model in vivo. |
Contact Information:
Name: Prof. Frank Ji
Phone: 215.895.2562
Email: hj56@drexel.edu |
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Location:
Disque Hall, Room 109, 32 South 32nd Street, Philadelphia, PA 19135 |
Audience:
AlumniCurrent StudentsFacultyProspective StudentsGraduate Students |
Special Features:
Free Food |
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