Session V19: Focus Session: Ultrafast Dynamics using X-rays and Electrons II

11:15 AM–2:15 PM, Thursday, March 8, 2007
Colorado Convention Center - 104

Sponsoring Unit: DCP
Chair: Christoph Rose-Petruck, Brown University

Abstract ID: BAPS.2007.MAR.V19.3

Abstract: V19.00003 : Watching proteins function with 150-ps time-resolved X-ray crystallography

12:27 PM–1:03 PM

Preview Abstract

Author:

  Philip Anfinrud
    (National Institutes of Health/NIDDK/LCP)

We have used time-resolved Laue crystallography to characterize ligand migration pathways and dynamics in wild-type and several mutant forms of myoglobin (Mb), a ligand-binding heme protein found in muscle tissue. In these pump-probe experiments, which were conducted on the ID09B time-resolved beamline at the European Synchrotron and Radiation Facility, a laser pulse photodissociates CO from an MbCO crystal and a suitably delayed X-ray pulse probes its structure via Laue diffraction. Single-site mutations in the vicinity of the heme pocket docking site were found to have a dramatic effect on ligand migration. To visualize this process, time-resolved electron density maps were stitched together into movies that unveil with $<$2-{\AA} spatial resolution and 150-ps time-resolution the correlated protein motions that accompany and/or mediate ligand migration. These studies help to illustrate at an atomic level relationships between protein structure, dynamics, and function.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.MAR.V19.3