Crystallography-assisted Raman spectroscopy: X-ray induced photodissociation monitored by Raman microscopy

Currently, few sites provide the possibility to perform simultaneous Raman/X-ray diffraction of single macromolecular crystals. In this recent Raman-assisted crystallography applications, Raman microscopy has been representing a fine servant of a dominant X-ray Crystallography, and its highest scope was the reinforcement of structural data [1, 2]. The strategy of our work is to overturn this paradigm, focusing Crystallography-assisted Raman on the rich spectroscopic information that are well transferable to many bio-analytical applications. A Synchrotron with available Raman microscope, SLS [3], has been used to collect high-resolution crystallographic data on unusual states of model biomolecules. Two cases of study are presented: a) NO photodissociation in hemoglobin crystal structure; b) ultra high resolution crystal structure (0.8 Å) of ribonuclease A at different X- ray doses. [1] Katona, G., et al. (2007) Science, 316, 449. [2] Vergara, A et al. (2010) J. Biol. Chem. 285,, 32568. [3] Owen, R. L., et al. (2009). J. Synchrotron Rad. 16, 173-182.