JBScreen Pentaerythritol has been designed for efficient crystallization screening of biological macromolecules based on pentaerythritol polymers as precipitants. The screen was developed by Ulrike Demmer from the Max-Planck-Institute for Biophysics in Frankfurt.
The choice of a suitable precipitant is of crucial importance for the crystallization of proteins. JBScreen Pentaerythritol utilizes two novel precipitating agents, i.e. pentaerythritol propoxylate and pentaerythritol ethoxylate. Both are branched polymers containing a pentaerythritol backbone. Thus they differ from more traditional precipitants like MPD and PEG’s in size and nature.
In addition, pentaerythritol polymers function as cryoprotectants. Protein crystals grown in high concentrations of these precipitants can be frozen directly from the crystallization drop. The successful application of pentaerythritol polymers to yield protein crystals was first described by Gulick et al. . Furthermore, this class of precipitants has been used for membrane crystallization: The X-ray structure of cbb3 Cytochrome Oxidase was published in Science in 2010. Crystals of this proton pumping membrane protein were successfully grown using pentaerythritol ethoxylate as precipitation agent .
JBScreen Pentaerythritol comprises of 96 unique conditions, based on 4 different pentaerythritol polymers as precipitating agent:
Bulk – 24 or 96 screening solutions in 10 ml aliquots
HTS – 96 screening solutions delivered in a deep-well block, 1.7 ml per well
 Gulick et al. (2002) Pentaerythritol propoxylate: a new crystallization agent and cryoprotectant induces crystal growth of 2-methylcitrate dehydratase. Acta Cryst. D58:306.
 Buschmann et al. (2010) The Structure of cbb3 Cytochrome Oxidase Provides Insights into Proton Pumping. Science 329:327.