PROTEIN CRYSTALLOGRAPHY WITH NON-DETERGENT SULFOBETAINES

The use in protein crystal growth of the newly described non-detergent solubilizers/stabilizers sulfobetaines (NDSB) has been investigated w ith crystallographic methods. In the classic model of egg white lysozy me crystallization by NaCl, NDSB increased the protein solubility and the crystal growth rate without influencing the quality of crystals as shown by Wilson plots. Sulphur anomalous X-ray scattering was used to show the absence of any bound NDSB in the crystals, A practical examp le of the use of NDSB is given for Desulfovibrio Gigas type II ferrodo xin, where NDSB contributed to reduction in crystal twinning and resul ted in the growth of a new crystal form. With their unique combination of solubilizing and stabilizing properties, the NDSB molecules might prove to be valuable additives for protein crystal growth.