Monitoring the preparation of protein derivative crystals via Raman-microscopy

Raman microscopy is having increasing applications into molecular biology. Primary structure features can be analyzed, such as Se-Met labeled protein crystals to be used for MAD crystallography [1] or to check heavy metal incorporation in isomorphous derivative crystals. Secondary structure modification can be clearly identified according to relationships between amide band frequencies and Ramachandran angles [2]. Ligand binding [3] and protein dynamics/reactivity can also be efficiently followed. The combined Raman and X-ray crystallography approach reinforces the interpretation of biophysical data. In particular, reactivity and dynamics of metal proteins have been investigated. This approach is particularly informative and well developed for hemoproteins [4, 5]. [1] A. Vergara, A. Merlino, E. Pizzo, G. D'Alessio, L. Mazzarella, Acta Cryst. D. (2008) D64, 167-171. [2] A. Merlino, F. Sica, A. Zagari, L. Mazzarella, A. Vergara, Biophys. Chem. (2008), 137, 24-27. [3] P. R. Carey, Ann. Rev. Phys. Chem. 2006, 57, 527-554. [4] L. Vitagliano, A. Vergara, G. Bonomi, A. Merlino, G. Smulevich, B. Howes, G. di Prisco, C. Verde, L. Mazzarella, J. Am. Chem. Soc. (2008) 130, 10527-10535. [5] A. Merlino, L. Vitagliano, B. Howes, C. Verde, G. di Prisco, G. Smulevich, F. Sica, A. Vergara, Biopolymers (2009), 91(12), 1117-1125. PRIN is acknowledged for financial support. Keywords: metal protein, ligand soaking, secondary structur