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Hungerford, United Kingdom

Shaw Stewart P.,Douglas Instruments Ltd. | Mueller-Dieckmann J.,University of Hamburg
Acta Crystallographica Section F:Structural Biology Communications

Crystallization remains the bottleneck in the crystallographic process leading from a gene to a three-dimensional model of the encoded protein or RNA. Automation of the individual steps of a crystallization experiment, from the preparation of crystallization cocktails for initial or optimization screens to the imaging of the experiments, has been the response to address this issue. Today, large high-throughput crystallization facilities, many of them open to the general user community, are capable of setting up thousands of crystallization trials per day. It is thus possible to test multiple constructs of each target for their ability to form crystals on a production-line basis. This has improved success rates and made crystallization much more convenient. High-throughput crystallization, however, cannot relieve users of the task of producing samples of high quality. Moreover, the time gained from eliminating manual preparations must now be invested in the careful evaluation of the increased number of experiments. The latter requires a sophisticated data and laboratory information-management system. A review of the current state of automation at the individual steps of crystallization with specific attention to the automation of optimization is given. © 2014 International Union of Crystallography All rights reserved. Source

Kolek S.A.,Douglas Instruments Ltd. | Brauning B.,TU Munich | Shaw Stewart P.D.,Douglas Instruments Ltd.
Acta Crystallographica Section:F Structural Biology Communications

Random microseed matrix screening (rMMS), in which seed crystals are added to random crystallization screens, is an important breakthrough in soluble protein crystallization that increases the number of crystallization hits that are available for optimization. This greatly increases the number of soluble protein structures generated every year by typical structural biology laboratories. Inspired by this success, rMMS has been adapted to the crystallization of membrane proteins, making LCP seed stock by scaling up LCP crystallization conditions without changing the physical and chemical parameters that are critical for crystallization. Seed crystals are grown directly in LCP and, as with conventional rMMS, a seeding experiment is combined with an additive experiment. The new method was used with the bacterial integral membrane protein OmpF, and it was found that it increased the number of crystallization hits by almost an order of magnitude: without microseeding one new hit was found, whereas with LCP-rMMS eight new hits were found. It is anticipated that this new method will lead to better diffracting crystals of membrane proteins. A method of generating seed gradients, which allows the LCP seed stock to be diluted and the number of crystals in each LCP bolus to be reduced, if required for optimization, is also demonstrated. © 2016 International Union of Crystallography. Source

Garcia-Caballero A.,Instituto Andaluz Of Ciencias Of La Tierra Csic Ugr | Gavira J.A.,Instituto Andaluz Of Ciencias Of La Tierra Csic Ugr | Pineda-Molina E.,Instituto Andaluz Of Ciencias Of La Tierra Csic Ugr | Chayen N.E.,Imperial College London | And 19 more authors.
Crystal Growth and Design

Protein crystallization has gained a new strategic and commercial relevance in the postgenomic era due to its pivotal role in structural genomics. Producing high quality crystals has always been a bottleneck to efficient structure determination, and this problem is becoming increasingly acute. This is especially true for challenging, therapeutically important proteins that typically do not form suitable crystals. The OptiCryst consortium has focused on relieving this bottleneck by making a concerted effort to improve the crystallization techniques usually employed, designing new crystallization tools, and applying such developments to the optimization of target protein crystals. In particular, the focus has been on the novel application of dual polarization interferometry (DPI) to detect suitable nucleation; the application of in situ dynamic light scattering (DLS) to monitor and analyze the process of crystallization; the use of UV-fluorescence to differentiate protein crystals from salt; the design of novel nucleants and seeding technologies; and the development of kits for capillary counterdiffusion and crystal growth in gels. The consortium collectively handled 60 new target proteins that had not been crystallized previously. From these, we generated 39 crystals with improved diffraction properties. Fourteen of these 39 were only obtainable using OptiCryst methods. For the remaining 25, OptiCryst methods were used in combination with standard crystallization techniques. Eighteen structures have already been solved (30% success rate), with several more in the pipeline. © 2011 American Chemical Society. Source

Gavira J.A.,Instituto Andaluz Of Ciencias Of La Tierra Csic Ugr | Hernandez-Hernandez M.A.,Instituto Andaluz Of Ciencias Of La Tierra Csic Ugr | Gonzalez-Ramirez L.A.,Instituto Andaluz Of Ciencias Of La Tierra Csic Ugr | Briggs R.A.,Douglas Instruments Ltd. | And 2 more authors.
Crystal Growth and Design

A new method of increasing the success rate in protein crystallization screening experiments by combining microseeding with counter-diffusion crystallization in capillaries (SCD) is presented. We have investigated the number of crystallization hits obtained with and without microseeding with 10 model proteins. For the cases studied, SCD generally increases the number of hits and is particularly useful when only relatively low protein concentration stocks are available, either because the stocks were prepared for, e.g., vapor diffusion experiments, or because the protein is poorly soluble. In either case, the addition of seeds becomes necessary to overcome the nucleation energy barrier so that crystal growth can take place even when the wave of supersaturation that passes along the capillary is insufficient to promote nucleation. © 2011 American Chemical Society. Source

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