Protein Robots

Researchers are facing difficulties in improving the properties and response rates of chemomechanical andelectrochemomechanical systems based on polymer gels or proteins that are intended to be used as actuators in robotics. Lack of mechanical toughness and long-term durability are other problems to be solved. A basic improvement in the low efficiency... 

A regularly formed crystal of reasonable size (typically >500 pm in each dimension) is required for X-ray diffraction. Samples of pure protein are screened against a matrix of buffers, additives, or precipitants for conditions under which they form crystals. This can require many thousands of trials and has benefited from increased automation over the past five years. Most large crystallographic laboratories now have robotics systems, and the most sophisticated also automate the visualization of the crystallization experiments, to monitor the appearance of crystalline material. Such developments [e.g., Ref. 1] are adding computer visualization and pattern recognition to the informatics requirements. 

Londo, T., Lynch, R, Kehoe, T., Meys, M., and Gordon, N., Accelerated recombinant protein purification process development. Automated, robotics-based intergration of chromatographic purification and analysis, /. Chromatogr. A, 798, 73, 1998. 

Directed evolution relies on the analysis of large numbers of clones to enable the discovery of rare variants with unproved function. In order to analyze these large libraries, methods of screening or selection have been developed, many of which use specialized equipment or automation. These range from the use of multichannel pipettes, all the way up to robotics, depending on the level of investment [59]. Specialized robotic systems are available to perform tasks such as colony picking, cell culture, protein purification, and cell-based assays. 

The European Molecular Biology Laboratory s (EMBL s) offers a well-equipped pro-teomics laboratory in its facilities at the Proteomics Visitor Facility (Heidelberg, Germany). The services in MB concern protein isolation, imaging, and robotics sample preparation, supported by some other analytical facilities. 

Typical protein precipitation procedures use one volume of plasma plus three to six volumes of acetonitrile or methanol (or a mixture) with the internal standard at an appropriate concentration for the assay. Poison et al.102 reported that protein precipitation using acetonitrile eliminates at least 95% of the proteins after filtration or centrifugation, the supernatant can often be directly injected into the HPLC/MS/MS system. Usually this step is performed using 96-well plates that are ideal for semi-automation of sample preparation. Briem et al.103 reported on a robotic sample preparation system for plasma based on a protein precipitation step and a robotic liquid handling system that increased throughput by a factor of four compared to a manual system. 

Microbatch crystallization has recently become a popular choice, for a number of reasons. First, microbatch generally uses much less protein and reagents than vapor diffusion. In addition, microbatch is much more amenable to using robotics, and there are a number of proteomics groups that have turned to microbatch for their high-throughput programs. Lastly, microbatch will often yield different crystallization conditions than vapor diffusion (Baldock et al., 1996), so the two methods can be complementary to each other. 

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