Crystallization and preliminary X-ray analysis of human alpha-galactosidase A complex

Human alpha-galactosidase A (alpha-D-galactoside galactohydrolase; EC 3.2.1.22), the glycosylated lysosomal enzyme deficient in Fabry disease, has been crystallized as a complex with the inhibitor N-6-aminohexanoyl-alpha-D-galactopyranosylamine. The "hanging drop" method of vapor diffusion was used to grow crystals from solutions containing 50 mM sodium phosphate (pH 4.0 to 4.5), 120 to 170 mM ZnCl2 and 8 to 10% polyethylene glycol 3350. X-ray diffraction data collected from these crystals indicate that the crystals belong to the orthorhombic space group C222(1) with cell dimensions of a = 93.8 A, b = 141.1 A and c = 184.4 A. The crystals diffract to a resolution of 3 A and native data have been collected to 3.5 A resolution. Assuming one dimer per asymmetric unit with a total molecular mass of 110 kDa (with oligosaccharide chains), the Matthews' coefficient is Vm = 2.77 A3/dalton corresponding to a solvent content of 55% (v/v). The self-rotation function reveals that a non-crystallographic 2-fold axis relates the subunits of each dimer.