CRYSTALLIZATION AND PRELIMINARY-X-RAY DIFFRACTION STUDIES OF A DEGLYCOSYLATED GLUCOSE-OXIDASE FROM PENICILLIUM-AMAGASAKIENSE

The dimeric glucose oxidase from Penicillium amagasakiense was deglycosylated, purified and crystallized as a complex with its coenzyme FAD. Deglycosylation and purification to isoelectric homogeneity were shown to be an important prerequisite step to obtain crystals suitable for X-ray investigations. Crystals of the deglycosylated enzyme were reproducibly grown using ammonium sulfate as precipitant at pH 7.4 to 7.5. Crystals diffract to at least 2.0 Å resolution and belong to the orthorhombic space group P212121, with refined lattice constants of a = 59.3 A ̊, b = 136.3 A ̊ and c = 156.7 A ̊. Assuming two monomers (≈ 135 kDa) per asymmetric unit the Vm value is 2.3 Å3/Da. © 1992.