Berlin 2018 – wissenschaftliches Programm
KFM 23.2: Vortrag
Donnerstag, 15. März 2018, 10:00–10:20, EMH 025
3D printing at the diffraction limit: sample injection for time-resolved serial crystallography — •Michael Heymann — MPI of Biochemistry, Am Klopferspitz 18, 82152 Martinsried
Continuous injection using the Gas Dynamic Virtual Nozzle (GDVN) is a proven sample delivery method for biological imaging using X-ray free-electron lasers. However, many important aspects of GDVN functionality have yet to be thoroughly understood and/or refined due to fabrication limitations. We report the application of 2-photon polymerization as a form of high-resolution 3D printing to fabricate GDVNs with submicron resolution. This allows rapid prototyping of a wide range of nozzle designs from standard CAD drawings to iteratively optimize crucial dimensions for optimal performance. To understand enzyme catalysis and protein conformational changes at the atomic scale, we pioneered mixing-injectors for time-resolved structural biology to record molecular movies of substrate turn-over. We experimentally validate 3D print accuracy, as well as fluid mixing dynamics using X-ray tomographic imaging. We developed mixing-injectors to mix nanocrystals with substrate and to subsequently deliver them into the X-ray interaction region just milliseconds after mixing. This method can determine the structures of transient states and thereby kinetic mechanisms. In a proof of principle experiment, we could follow the catalytic reaction of the M. tuberculosis β-lactamase with the 3rd generation antibiotic ceftriaxone by time-resolved serial crystallography with millisecond to second time resolution at 2Å spatial resolution.