Structural biology has developed rapidly over the last decade, driven by the various genome projects around the world and by advances in the field of biomolecular crystallisation. X-ray diffraction from macromolecular crystals is used to reveal the atomic arrangement of proteins, nucleic acids and viruses. In this respect, macromolecular crystallography is a powerful tool in the drug-design process. The outstanding properties of the X-ray beams provided by synchrotron radiation sources are now essential for collecting high-quality diffraction data. Pharmaceutical companies appreciate the rapid data collection on very small crystals and at higher resolution than with conventional X-ray sources.

The ESRF's crystallography beamlines have seen a large increase in demand for beamtime from industry in recent years. Companies are also requesting faster access to the synchrotron facilities. Therefore, a data collection service was set up, whereby the user sends their frozen samples to ESRF. The experiments are carried out by two scientists (S. Monaco and E. Gordon, Figure 145) and the collected data are sent back to the users, usually within a few weeks. This procedure is advantageous for both parties since industrial personnel no longer have to travel to ESRF on a regular basis and they benefit from fast sample processing by on-site staff experienced in both crystallography and synchrotron radiation, while the ESRF improves the overall efficiency of its beamlines. This service is called MXpress. The pilot study began in February 2002 with a limited number of samples per month being sent by Aventis Pharma, Paris.

 

Fig. 145: Dr E. Gordon (left) and Dr S. Monaco (right), the two scientists taking care of the MXPress service.

 

Several tools for automation of the crystallography beamlines have been implemented over the last two years (see 'Further steps towards beamline automation' for more details). MXpress has been used as the test bench for some of these tools and has encouraged development of the others. PXweb (Figure 146), our beamlines Laboratory Information Management (LIM) system, is intimately linked to the MXpress service since it allows on-line reporting of the current experiment. As it is a Web service, users can provide ESRF staff with an exhaustive description of the dewar contents and follow the experiment being carried out in real time. During data collection they can retrieve their data through the internet and interact with the staff present on-site and so modify the experiment's progress. Other very recent tools are the automatic sample centring software from EMBL Grenoble currently available on ID14-3, and the DNA software for automated data collection and processing currently available on all ESRF MX beamlines. This software uses two reference diffraction patterns to deduce the crystal orientation in the beam and propose a data collection strategy. Finally the EMBL-ESRF sample changer has been available on ID14-3 since December 2003 and will be installed on the other beamlines starting mid 2004.

 

Fig. 146: Pxweb, the ESRF's Macromolecular crystallography LIM system.

 

The MXpress service was made available to other industrial companies in January 2003. There are now 10 different sites around the world sending samples to ESRF on a regular basis and over 600 samples were screened in 2003. Further developments and improvements may eventually lead to the possibility of offering a complete structure-determination service to industrial companies.

Authors
S. Monaco and E. Gordon.
ESRF