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An alternate sucrose binding mode in the E203Q Arabidopsis invertase mutant: An X-ray crystallography and docking study KU Leuven

Janka Matrai, Willem Lammens, Abel Jonckheer, Katrien Le Roy, Anja Rabijns, Wim Van den Ende, Marc De Maeyer
In the present study, we report on the X-ray crystallographic structure of a GH32 invertase mutant, (i.e., the Arabidopsis thaliana cell-wall invertase 1-E203Q, AtcwINV1-mutant) in complex with sucrose. This structure was solved to reveal the features of sugar binding in the catalytic pocket. However, as demonstrated by the X-ray structure the sugar binding and the catalytic pocket arrangement is significantly altered as compared with what was ...

Expression, purification and X-ray crystallographic analysis of the Helicobacter pylori blood group antigen-binding adhesin BabA Vrije Universiteit Brussel

Suresh Subedi, Kristof Moonens, Ema Romao, Alvin Wei Han Lo, Guy Vandenbussche, Jeanna Bugaytsova, Serge Muyldermans, Thomas Borén, Han Remaut

Helicobacter pylori is a human pathogen that colonizes about 50% of the world's population, causing chronic gastritis, duodenal ulcers and even gastric cancer. A steady emergence of multiple antibiotic resistant strains poses an important public health threat and there is an urgent requirement for alternative therapeutics. The blood group antigen-binding adhesin BabA mediates the intimate attachment to the host mucosa and forms a major ...

Crystallization and preliminary X-ray crystallographic analysis of putative tRNA-modification enzymes from Pyrococcus furiosus and Thermus thermophilus Vrije Universiteit Brussel

Marcus Fislage, M. Roovers, Stefan Münnich, L. Droogmans, Wim Versées
Methyltransferases form a major class of tRNA-modifying enzymes that are needed for the proper functioning of tRNA. Here, the expression, purification and crystallization of two related putative tRNA methyltransferases from two kingdoms of life are reported. The protein encoded by the gene pf1002 from the archaeon Pyrococcus furiosus was crystallized in the monoclinic space group P2(1). A complete data set was collected to 2.2 angstrom ...

Using neutron crystallography to elucidate the basis of selective inhibition of carbonic anhydrase by saccharin and a derivative Vrije Universiteit Brussel

Katarina Koruza, Brian P. Mahon, Matthew P. Blakeley, Andreas Ostermann, Tobias E. Schrader, Robert McKenna, Wolfgang Knecht, S. Zoë Fisher

Up-regulation of carbonic anhydrase IX (CA IX) expression is an indicator of metastasis and associated with poor cancer patient prognosis. CA IX has emerged as a cancer drug target but development of isoform-specific inhibitors is challenging due to other highly conserved CA isoforms. In this study, a CA IX mimic construct was used (CA II with seven point ...

NMR Crystallography Reveals Carbonate Induced Al-Ordering in ZnAl Layered Double Hydroxide KU Leuven

Sambhu Radhakrishnan, Vinodchandran Chandrasekharan Nair, Sreeprasanth Pulinthanathu Sree, Johan Martens, Christine Kirschhock, Eric Breynaert
Layered double hydroxides (LDHs) serve a score of applications in catalysis, drug delivery, and environmental remediation. Smarter crystallography, combining X-ray diffraction and NMR spectroscopy revealed how interplay between carbonate and pH determines the LDH structure and Al ordering in ZnAl LDH. Carbonate intercalated ZnAl LDHs were synthesized at different pH (pH 8.5, pH 10.0, pH 12.5) with a Zn/Al ratio of 2, without subsequent ...

Highly stable and porous porphyrin-based zirconium and hafnium phosphonates - electron crystallography as an important tool for structure elucidation KU Leuven

Bart Bueken, Dirk De Vos
The Ni-metallated porphyrin-based tetraphosphonic acid (Ni-tetra(4-phosphonophenyl)porphyrin, Ni-H8TPPP) was used for the synthesis of highly porous metal phosphonates containing the tetravalent cations Zr4+ and Hf4+. The compounds were thoroughly characterized regarding their sorption properties towards N2 and H2O as well as thermal and chemical stability. During the synthesis optimization the reaction time could be substantially decreased ...

Solving the Hydrogen and Lithium Substructure of Poly(triazine imide)/LiCl Using NMR Crystallography KU Leuven

Francis Taulelle
Poly(triazine imide) with incorporated lithium chloride has recently attracted substantial attention due to its photocatalytic activity for water splitting. However, an apparent H/Li disorder prevents the delineation of structure-property relationships, for example, with respect to band-gap tuning. Herein, we show that through a combination of one- and two-dimensional, multinuclear solid-state NMR spectroscopy, chemical modelling, automated ...

High-resolution X-ray diffraction with no sample preparation KU Leuven

Patrick Degryse
It is shown that energy-dispersive X-ray diffraction (EDXRD) implemented in a back-reflection geometry is extremely insensitive to sample morphology and positioning even in a high-resolution configuration. This technique allows high-quality X-ray diffraction analysis of samples that have not been prepared and is therefore completely non-destructive. The experimental technique was implemented on beamline B18 at the Diamond Light Source ...

XRDUA: crystalline phase distribution maps by two-dimensional scanning and tomographic (micro) X-ray powder diffraction KU Leuven

Koen Janssens
Imaging of crystalline phase distributions in heterogeneous materials, either plane projected or in virtual cross sections of the object under investigation, can be achieved by scanning X-ray powder diffraction employing X-ray micro beams and X-ray-sensitive area detectors. Software exists to convert the two-dimensional powder diffraction patterns that are recorded by these detectors to one-dimensional diffractograms, which may be analysed by ...