A novel BioXAS technique with sub-millisecond time resolution to track oxidation state and structural changes at biological metal centers.
Oxidation-state and structural changes at the metal center are crucial for the catalytic reactions of most metalloenzymes. The characterization of reaction intermediates is a prerequisite for understanding the catalytic mechanism. Frequently, intermediates are formed on the microsecond to millisecond timescale. To follow these reactions in real time represents a major challenge in structural biology. Time-resolved BioXAS is a particularly promising tool for resolving such intermediates. A novel approach for BioXAS, termed 'sampling-XAS', is presented. First room-temperature sampling-XAS results have been obtained for the manganese complex of oxygenic photosynthesis. Oxidation-state changes are monitored with a time resolution as good as 200 micros. The current prospects and limitations as well as future perspectives of time-resolved BioXAS are discussed.
Haumann
Michael
M
Freie Universität Berlin, FB Physik, Arnimallee 14, D-14195 Berlin, Germany. haumann@physik.fu-berlin.de
Müller
Claudia
C
Liebisch
Peter
P
Neisius
Thomas
T
Dau
Holger
H
D002384:Catalysis; D003198:Computer Simulation; D004798:Enzymes / Q000737:chemistry / Q000378:metabolism; D008345:Manganese / Q000378:metabolism*; D008667:Metalloproteins; D010084:Oxidation-Reduction; D045322:Photosynthetic Reaction Center Complex Proteins; D011487:Protein Conformation; D013057:Spectrum Analysis / Q000379:methods*; D014867:Water / Q000378:metabolism; D014965:X-Rays
D004798:Enzymes; D008667:Metalloproteins; D045322:Photosynthetic Reaction Center Complex Proteins; D014867:Water; D008345:Manganese