Jean Jakoncic Wins Esteemed Student Lecturer Award
From X6AWiki
National Synchrotron Light Source student researcher Jean Jakoncic has won the prestigious Margaret C. Etter Student Lecturer Award for researching the use of high-energy x-rays to prevent crystal damage in diffraction studies.
He received the award at the American Crystallographic Association national meeting, held in Honolulu, Hawaii, on July 22-27, where he also gave a talk on the subject. The Etter award, given out just once a year, recognizes achievement and future potential for scientists at an early stage in their independent careers.
Jakoncic, a graduate student from Joseph Fourier University working toward his Ph.D. in structural biology, came to the NSLS four years ago. Conducting research primarily at NSLS beamline X6A (under the supervision of Vivian Stojanoff), in addition to X17B1 and the European Synchrotron Radiation Facility (ESRF) beamline ID15B, Jakoncic helped to show that high-energy x-rays could be an option for the structural determination of radiation-sensitive proteins. In addition to Stojanoff, he worked with NSLS scientist Zhong Zhong and ESRF scientists Marco Di Michiel and Veijo Honkimaki.
Traditionally, people use medium- and low-energy x-rays for diffraction studies of protein samples, Jakoncic said. At these energies, there is a significant amount of energy deposited in the crystal and substantially there is radiation damage. We propose to use higher energies, where the energy deposition is about 10 to 15 times less than at lower-energy x-rays.
To visualize radiation damage, the group exposed lyzozyme crystals, which are standard test protein crystals, to high-energy and low-energy x-rays and compared the results. With the same resolution limit, we did not see any radiation damage at 55 keV, the high-energy data, while we observed radiation damage at 12 keV, Jakoncic said, adding that plans for additional testing with crystals from different proteins are underway. This is the first step, he said.
akoncic describes his efforts associated with the high-energy x-ray research as a satellite project in relation to his other scientific interests. His core research at the NSLS focuses on enzymes involved in the degradation of toxic compounds, in particular polycyclic aromatic hydrocarbons (PAH). He expects to defend his thesis on this topic in the following months.
ARTICLE BY: Kendra Snyder
