PHOTOLYSIS OF THE CARBON-MONOXIDE COMPLEX OF MYOGLOBIN - NANOSECOND TIME-RESOLVED CRYSTALLOGRAPHY

The biological activity of macromolecules is accompanied by rapid stru ctural changes. The photosensitivity of the carbon monoxide complex of myoglobin was used al the European Synchrotron Radiation Facility to obtain pulsed, Laue x-ray diffraction data with nanosecond time resolu tion during the process of heme and protein relaxation after carbon mo noxide photodissociation and during rebinding. These time-resolved exp eriments reveal the structures of myoglobin photoproducts, provide a s tructural foundation to spectroscopic results and molecular dynamics c alculations, and demonstrate that time-resolved macromolecular crystal lography can elucidate the structural bases of biochemical mechanisms on the nanosecond time scale.