THE PRODUCTION AND X-RAY STRUCTURE DETERMINATION OF PERDEUTERATED STAPHYLOCOCCAL NUCLEASE

Staphylococcal diffraction data quality using fully perdeuterated prot ein. Large quantities of the protein were expressed in Escherichia col i grown in medium containing deuterated amino acids and deuterated wat er (D2O) and then purified. The mean perdeuteration level of the non-e xchangable sites in the protein was found to be 96% by electrospray io nization mass spectrometry. The perdeuterated enzyme was crystallized and its X-ray structure determined. Crystals of perdeuterated SNase ha ve been grown to 1.5 mm(3). Crystallization conditions, space group an d cell parameters were found to be the same for both native and perdeu terated forms of the protein. Comparison of these two forms of SNase r evealed no significant structural differences between them at the atom ic resolution of 1.9 Angstrom. Data collection using crystals of the p erdeuterated protein is scheduled at the Brookhaven High Flux Beam Rea ctor.