Crystallization and preliminary X-ray analysis of a vanadium-dependent peroxidase from Ascophyllum nodosum

Peroxidase from the brown alga Ascophyllum nodosum, a non-heme vanadium-dependent haloperoxidase, has been purified to homogeneity and crystallized from ammonium sulfate solutions in a form suitable for X-ray diffraction analysis. The crystals have been grown by the vapour-diffusion technique using the sitting-drop method. X-ray diffraction studies show that the crystals belong to the tetragonal space group P4₁2₁2 or P4₃2₁2 with a = b = 114.3 and c = 276.0 Å. The crystals diffract to at least 2.4 Å resolution.