The first crystallization of a vanadium‐dependent peroxidase

Single crystals of a vanadium‐containing peroxidase from the brown alga Ascophyllum nodosum have been grown by the vapour diffusion technique using polyethylene glycol 6000 along with sodium chloride as precipitant. The crystals belong to the monoclinic space group P2 1 . X‐ray diffraction extends to at least 2.4 Å. The cell dimensions a = 173.0, b = 164.9, c =68.5 Å, β=94.5° indicate that there are four molecules of 100 kDa per asymmetric unit, suggesting that the native enzyme might occur as a tetramer.