Upgraded with the Anderson−Evans polyoxotungstate [TeW6O24]6− (TEW) as universal additive, the XP Screen promotes protein crystallization even for most challenging targets and improves diffraction quality of protein crystals. Its potential has been shown in the new protein structures of aurone synthase from Coreopsis grandiflora[2-4] (PDB code: 4Z12, 4Z13) and mushroom tyrosinase PPO4 from Agaricus bisporus[6,7] (PDB code: 4OUA). The model protein lysozyme crystallized into a new crystal form (PDB code: 4PHI).
The XP Screen is a TEW-optimized JBScreen Basic: 96 of the most prominent crystallization conditions complemented with TEW as "glue" for protein molecules.
Protein-protein bridging by TEW in different orientations
Image from , used by courtesy of Prof. Annette Rompel, University of Vienna, Austria
 Bijelic et al. (2017) Ten Good Reasons for the Use of the Tellurium-Centered Anderson-Evans Polyoxotungstate in Protein Crystallography. Acc. Chem. Res. 50:1441.
 Molitor et al. (2016) Aurone synthase is a catechol oxidase with hydroxylase activity and provides insights into the mechanism of plant polyphenol oxidases. Proc. Natl. Acad. Sci. 113:E1806.
 Molitor et al. (2016) In situ formation of the first proteinogenically functionalized [TeW6O24O2(Glu)]7- structure reveals unprecedented chemical and geometrical features of the Anderson-type cluster. Chem. Commun. 52:12286.
 Molitor et al. (2015) Crystallization and preliminary crystallographic analysis of latent, active and recombinantly expressed aurone synthase, a polyphenol oxidase, from Coreopsis grandiflora. Acta Cryst. F 71:746.
 Bijelic et al. (2015) Hen Egg-White Lysozyme Crystallisation: Protein Stacking and Structure Stability Enhanced by a Tellurium(VI)-Centred Polyoxotungstate. ChemBioChem 16:233.
 Mauracher et al. (2014) Latent and active abPPO4 mushroom tyrosinase cocrystallized with hexatungstotellurate(VI) in a single crystal. Acta Cryst. D 70:2301.
 Mauracher et al. (2014) Crystallization and preliminary X-ray crystallographic analysis of latent isoform PPO4 mushroom (Agaricus bisporus) tyrosinase. Acta Cryst. F 70:263.