Göttingen scientists use BESSY II to decode basic mechanism underlying biochemical reactions
Structure of the sugar molecule bound by the enzyme transketolase immediately prior to its being split
Enzymes are life’s molecular catalysts and figure prominently in cellular metabolism. It has been speculated that in the course of a biochemical reaction enzymes physically bend their substrates to split them. Now for the first time ever, scientists at the Göttingen Center for Molecular Biosciences (GZMB) have successfully used BESSY II's MX beamline to unequivocally confirm this hypothesis. The results from this study have been published in the renowned scientific journal Nature Chemistry.
The Göttingen team around Prof. Dr. Kai Tittmann and Prof. Dr. Ralf Ficner started out by growing high order protein crystals of the human enzyme transketolase, which plays a central role in human metabolism during sugar processing. Natural sugar substrates were added to the protein crystals. Analysis of the enzyme’s crystalline structure was subsequently performed at electron storage ring BESSY II's MX beamline and in French Grenoble. The scientists were able to determine the structure of the sugar molecule bound by the enzyme immediately prior to its being split in half at an ultrahigh spatial resolution of 0.1 nanometers. “The snapshot we got of an enzyme at work, which really is unprecedented in terms of resolution, unequivocally reveals how the sugar substrate is being bent by the enzyme, similar to a vise clamping a work piece,” Prof. Tittmann explains.
In many cases, enzymes are drug targets. Which is why these new insights are important for the development of customized, highly specific active substances like those used in cancer therapy. “Even the human transketolase used in this study plays a key role in cancer cell metabolism,” says Prof. Tittmann.
Source: Göttingen University
- Freeze casting - a guide to creating hierarchically structured materialsFreeze casting is an elegant, cost-effective manufacturing technique to produce highly porous materials with custom-designed hierarchical architectures, well-defined pore orientation, and multifunctional surface structures. Freeze-cast materials are suitable for many applications, from biomedicine to environmental engineering and energy technologies. An article in "Nature Reviews Methods Primer" now provides a guide to freeze-casting methods that includes an overview on current and future applications and highlights characterization techniques with a focus on X-ray tomoscopy.
- IRIS beamline at BESSY II extended with nanomicroscopyThe IRIS infrared beamline at the BESSY II storage ring now offers a fourth option for characterising materials, cells and even molecules on different length scales. The team has extended the IRIS beamline with an end station for nanospectroscopy and nanoimaging that enables spatial resolutions down to below 30 nanometres. The instrument is also available to external user groups.
- A simpler way to inorganic perovskite solar cellsInorganic perovskite solar cells made of CsPbI3 are stable over the long term and achieve good efficiencies. A team led by Prof. Antonio Abate has now analysed surfaces and interfaces of CsPbI3 films, produced under different conditions, at BESSY II. The results show that annealing in ambient air does not have an adverse effect on the optoelectronic properties of the semiconductor film, but actually results in fewer defects. This could further simplify the mass production of inorganic perovskite solar cells.