CRYSTALLIZATION AND PRELIMINARY-X-RAY ANALYSIS OF HUMAN ALPHA-GALACTOSIDASE A-COMPLEX

Human α-galactosidase Å (α-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-α-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 orthorbombic space group C2221 with cell dimensions of a = 93.8 Å, b = 141.1 Å and c = 184.4 Å. The crystals diffract to a resolution of 3 Å and native data have been collected to 3.5 Å resolution. Assuming one dimer per asymmetric unit with a total molecular mass of 110 kDa (with oligosaccharide chains), the Matthews' coefficient is V(m) = 2.77 Å3/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. © 1994 Academic Press Limited.