IUCr Webinar on Morpheus by Dr Fabrice Gorrec

Available to view now online

Earlier in the summer, Dr Fabrice Gorrec gave an IUCr webinar describing the methodology behind his popular Morpheus® screens. That Webinar is now available to view at the IUCr's YouTube channel, together with a video describing the four-corner method for optimizing Morpheus® hit conditions.

As our customers will know, Molecular Dimensions has a successful collaboration with Dr Gorrec to commercialize several of his very popular and successful screens. As a companion to these webinars, we review all 5 of Dr Gorrec's screens developed at the world-renowned MRC Laboratory of Molecular Biology, Cambridge, UK and exclusively licensed by them to Molecular Dimensions.

1. Morpheus®
2. Morpheus® II
3. Morpheus® Additive
4. The LMB Crystallization screen
5. The Angstrom Additive™ screen

1) Morpheus®

Available as 10 mL, HT-96 and FX-plate formulation. Single reagents and stock solutions available for hit optimisation.
This ever popular screen incorporates a range of low molecular weight compounds that were identified as frequently occurring ordered ligands in more than 33,000 structures from the PDB (PDB data from 2009). This unique screen aims to access novel chemical space left unexplored in conventional screens, primarily by integrating PDB-derived ligands in 8 additive mixes. Each mix contains a number of additives of the same chemical class.

The screen has been optimized in many ways, including maximising the concentration of additives and ensuring all conditions are cryoprotected. A number of biological buffers are among the pdb-derived ligands and have been used to build three buffer systems (for example MOPS/HEPES-Na). The resulting simplified and systematic screen formulation (a 96-well 3D grid screen) facilitates the preparation of conditions during the optimization of initial hits.

Morpheus® promotes crystal formation and increases lattice stability for more useful hits and higher resolution data. With PEG-based precipitant mixes the screen is ideal for both soluble and membrane proteins.

Reference: Gorrec, F. The MORPHEUS protein crystallization screen. Journal Applied Crystallography 42: 1035-42 (2009).

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2) Morpheus® II

Available as 10 mL, HT-96 and FX-plate formulation. Single reagent and stock solutions available for optimization.
A follow-up to the popular Morpheus® screen, Morpheus® II has been developed using the same approach (including low molecular weight compounds identifed as protein ligands in the PDB in 2015). However, in Morpheus® II, reagents not usually found in initial screens have been integrated to access new areas of crystallization space and provide useful hits when other screens have failed.

The 96 conditions include NDSBs, polyamines, amino acids and monosaccharides to increase protein solubility and stability. As with Morpheus®, these are combined in several mixes for efficient screening. Glycerol-like polyols are used for cryoprotection and some heavy atoms are included to aid experimental phasing. Finally, more innovative buffer systems are used.

References: Gorrec, F. The Morpheus II protein crystallization screen. Acta Crystallographica section F Structural Biology Communications 71: 831-837 (2015).
Gorrec, F. The current approach to initial crystallization screening of proteins is under-sampled. Journal of Applied Crystallography 46: 795-7 (2013).

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3) The Morpheus® Additive Screen

Available as a 96-well, 100 uL additive screen.
The Morpheus® Additive screen provides all the reagents employed to formulate the Morpheus® and Morpheus® II screens (including the PDB-derived ligands). The screen includes a large range of precipitants, buffers, nucleants, phasing compounds, cryoprotectants and surfactants to enhance the stability and solubility of your protein. This screen is ideal for optimizing your initial crystal hits.

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4) The LMB Crystallisation Screen

Available in 10 mL, HT-96 and FX-plate formulations, single reagents available for hit optimization.
This screen formulation is based on an analysis of the 1,440 conditions routinely used for screening between 2002 and 2009 at the MRC-LMB in Cambridge. Optimized conditions that led to structure deposition were used to create a 96-well sparse matrix screen. The screen is biased towards soluble proteins and their complexes.

Reference: Gorrec, F. Protein crystallization screens developed at the MRC Laboratory of Molecular Biology. Drug Discovery Today 21: 819-825 (2016).

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5) The Angstrom Additive Screen

Available as 96-well 1 mL deep-well block and 100 uL FX-plate.
Polyols can mediate protein-protein interactions via their multiple hydroxyl groups. This makes them great optimization reagents as they can readily enhance protein and lattice stability thus increasing crystal quality. The Angstrom Additive kit provides 30 different polyols at a range of concentrations. As an additional benefit of this additive screen, every polyol provided is a cryoprotectant, with some being as effective as glycerol (including those illustrated on the right).

Reference:Gorrec, F. Protein crystallization screens developed at the MRC Laboratory of Molecular Biology. Drug Discovery Today 21: 819-825 (2016).

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All the screens described here were developed at the MRC-LMB, Cambridge, UK and exclusively licensed to Molecular Dimensions by MRC Technology.