Metalloprotein structures at ambient conditions and in real-time: biological crystallography and spectroscopy using X-ray free electron lasers.
Although the structure of enzymes and the chemistry at the catalytic sites have been studied intensively, an understanding of the atomic-scale chemistry requires a new approach beyond steady state X-ray crystallography and X-ray spectroscopy at cryogenic temperatures. Following the dynamic changes in the geometric and electronic structure of metallo-enzymes at ambient conditions, while overcoming the severe X-ray-induced changes to the redox active catalytic center, is key for deriving reaction mechanisms. Such studies become possible by the intense and ultra-short femtosecond (fs) X-ray pulses from an X-ray free electron laser (XFEL) by acquiring a signal before the sample is destroyed. This review describes the recent and pioneering uses of XFELs to study the protein structure and dynamics of metallo-enzymes using crystallography and scattering, as well as the chemical structure and dynamics of the catalytic complexes (charge, spin, and covalency) using spectroscopy during the reaction to understand the electron-transfer processes and elucidate the mechanism.
Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA. Electronic address: JFKern@LBL.GOV.
Jan
J
Kern
Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Electronic address: VKYachandra@LBL.GOV.
Vittal K
VK
Yachandra
Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Electronic address: JYano@LBL.GOV.
Junko
J
Yano
D001665:Binding Sites; D018360:Crystallography, X-Ray; D007834:Lasers; D008667:Metalloproteins / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D013057:Spectrum Analysis; D013696:Temperature
D008667:Metalloproteins; D008670:Metals