Purification, crystallization and preliminary crystallographic study of neuraminidase from Vibrio cholerae and Salmonella typhimurium LT2.

The nanH genes of Vibrio cholerae and Salmonella typhimurium LT2 coding neuraminidase were cloned separately in Escherichia coli, and the expression products purified. Single crystals of the V. cholerae neuraminidase were obtained using the hanging drop vapour diffusion method with polyethylene glycol as precipitant at pH 7.2. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit cell dimensions a = 71.9 A, b = 79.0 A, c = 165.7 A, and with one molecule in the asymmetric unit. Diffraction extends to at least 2.5 A. Single crystals of the S. typhimurium neuraminidase were obtained by hanging drop with potassium phosphate as precipitant at pH 7.2. The crystals also belong to the orthorhombic space group P2(1)2(1)2(1), with unit cell dimensions a = 47.4 A, b = 82.8 A, c = 92.4 A, and with one molecule in the asymmetric unit. Diffraction extends to at least 1.8 A.