Remote Physics Experiment at ESRF (Experimental Synchrotron Research Facility), Grenoble, France on NKN

An experiment has recently been conducted accessing the Synchrotron at Grenoble, France from Homi Bhabha National Institute (HBNI), Mumbai, on NKN, for protein crystallography studies. Radiation produced in a third generation synchrotron is available only in a very few countries. This radiation has been used to determine the three dimensional structure of molecules by crystallography, enabling studies on structure-function relationships in biological macromolecules and design of new drugs.

NKN connects the HBNI to FIP (French beam line for Investigation of Protein), Grenoble, France through 2.5 Gbps Trans Eurasia Information Network (TEIN3) link to GEANT network in Europe. The actual beamline used was the FIP beamline set-up by Dr. Jean-Luc Ferrer and his colleagues to study structures of proteins. The X-radiation for this beamline is fed by the bending magnet on port number 30, and therefore the beamline is also referred to as BM30A. The experimental station at the end of the beamline consists of: 1) cryo-dewar with liquid nitrogen to store sample-containing pucks, 2) a six-axis sample-changer robot for transferring back and forth samples from cryo-dewar to the diffractometer, 3) a M2 single-axis microdiffractometer, and 4) ADSC quantum detector to record the diffraction pattern.

The beamline is fully automated thereby allowing for its remote operation. The operation of the beamline is controlled by softwares Xnemo and Gonio developed by Dr. Jacques Joley. Gonio is the software that enables selection, mounting and positioning of samples stored in a cryo-dewar containing liquid nitrogen. An on-axis view of the sample is also provided by this software. Xnemo is the software that enables setting of data collection types and parameters including detector distance. The software Visu enables one to monitor sample changes and detector movements. It also allows one to check if there is ice-formation on the sample crystal. The software NXclient installed on the local PC at HBNI imports the desktops of computers d30pc5 and d30pc3 used to control the beamline and visualize diffraction data at Grenoble.

Since establishment of the Remote Data Collection Facility, fifteen good quality data sets, each data set comprising of 180 oscillation frames, have been collected on protein samples that are part of the collaboration between Dr. Hosur M. V. at BARC and Dr. Jean-Luc Ferrer at IBS/ESRF, Grenoble, France. For example, 180 frames, each for an oscillation angle of 1O, were collected on crystals of drug-resistant M36I mutant HIV-1 protease, and the structure could be refined to very low R-factors. The OMIT density for the mutation residue is very clearly seen in the electron density map (see Figure 3 below). More recently, data on HIV-1 protease substrate complexes have been collected, and the refined map shows clear density for the ligand molecules in the active site. Another advantage of remote data collection is that the younger members of the laboratory can participate and get trained in using the mega facility such as the ESRF synchrotron. The diffraction data collected is stored temporarily on local computer at ESRF, before it is transferred to HBNI computer through FTP.

Figure 1 shows the experimental station on the FIP beam line (French beam line for Investigation of Proteins), which is dedicated to crystallography of biological macromolecules. The quality of data has been very good as evidenced by the OMIT electron density for the isoleucine residue in the mutant protein M36I, as shown in the Figure 3. The structure has since been refined to a resolution of 1.6 , and the crystallographic R-factors are: R-work = 0.18, R-free = 0.20. This facility has evoked a very enthusiastic response from the researchers.


Figure 1. Panoramic view of the FIP beam line at ESRF, showing: a) sample changer robots, b) diffractometer and c) Quantum CCD detector.

                                                                                    Figure 2. Remote Station at HBNI


                                                                                                                 
                                                                                           Figure 3(a).


                                                                                         Figure 3(b).

Figure 3. Depicts a one degree oscillation photograph on crystals of HIV-1 PR M36I mutant recorded by remotely operating the FIP beamline at ESRF, and OMIT density for the mutation residue I. (Credits: Dr. Jean-Luc Ferrer, Dr. Michel Pirochi & Dr. Jacques Joley, IBS/ESRF, France, Solid State Physics Division & Computer Division, BARC)

The representative examples cited above, are indicative of a sound beginning. With the reach envisaged by the NKN, the possibilities of collaborative research with institutes both within and outside India are indeed enormous. With an impressive roadmap of enhanced speed and connectivity envisaged by NKN, collaborative research has a fascinating future ahead.

The remote usage of FIP beam line at ESRF synchrotron facility, Grenoble, France was demonstrated live during the Asia 2 2011 Joint CHAIN/EU-India Grid2 EPIKH School for Application Porting during the 15th and 16th of February at VECC, Kolkata, India. Many researchers from Saha Institute of Nuclear Physics, Kolkata and participants of the workshop conducted experiments by remotely operating the Robot at ESRF to center the single crystal and obtaining diffraction patterns. This was very enthusiastically received by the Audience and was well appreciated. About 40 researchers participated in this event, which lasted for two days. The beam line at ESRF France was made available to this event on 15th and 16th of February between 17:30 Hrs (IST) and 19:30 Hrs