[en] Acetylene hydratase, a tungsten-containing hydroxylase that converts acetylene to acetaldehyde, has been purified and crystallized under anaerobic conditions

[en] The physiologically active form of nitrous oxide reductase was isolated and crystallized under strict exclusion of dioxygen and diffraction data were collected from crystals belonging to two different space groups. Nitrous oxide reductase (N₂OR) from Pseudomonas stutzeri catalyzes the final step in denitrification: the two-electron reduction of nitrous oxide to molecular dinitrogen. Crystals of the enzyme were grown under strict exclusion of dioxygen by sitting-drop vapour diffusion using 2R,3R-butanediol as a cryoprotectant. N₂OR crystallized in either space group P1 or P6₅. Interestingly, the key determinant for the resulting space group was the crystallization temperature. Crystals belonging to space group P1 contained four 130 kDa dimers in the asymmetric unit, while crystals belonging to space group P6₅ contained a single dimer in the asymmetric unit. Diffraction data were collected to resolutions better than 2 Å

[en] Human recombinant EF-hand Ca²⁺-binding protein S100B has been purified and crystallized. A complete data set was recorded to 1.9 Å. S100B, a Ca²⁺-binding protein, acts intracellularly as a Ca²⁺-signalling protein but is also secreted to the extracellular space, acting in a cytokine-like manner through its receptor RAGE. Recombinant human S100B has been purified and crystallized in the Ca²⁺-bound state. Size-exclusion chromatography indicates that S100B can exist as a dimer and as a multimer in solution. Crystals of S100B diffract to 1.9 Å and belong to space group P2₁, with unit-cell parameters a = 63.4, b = 81.6, c = 71.5 Å, α = 90, β = 107, γ = 90°. Preliminary analysis of the X-ray data indicate that there are four homodimers per asymmetric unit