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1.
The Oxidation of Thiols by Flavoprotein Oxidases: a Biocatalytic Route to Reactive Thiocarbonyls 下载免费PDF全文
Tom A. Ewing Willem P. Dijkman Prof. Dr. Jacques M. Vervoort Marco W. Fraaije Prof. Dr. Willem J. H. van Berkel 《Angewandte Chemie (International ed. in English)》2014,53(48):13206-13209
Flavoprotein oxidases are a diverse class of biocatalysts, most of which catalyze the oxidation of C? O, C? N, or C? C bonds. Flavoprotein oxidases that are known to catalyze the oxidation of C? S bonds are rare, being limited to enzymes that catalyze the oxidative cleavage of thioethers. Herein, we report that various flavoprotein oxidases, previously thought to solely act on alcohols, also catalyze the oxidation of thiols to thiocarbonyls. These results highlight the versatility of enzymatic catalysis and provide a potential biocatalytic route to reactive thiocarbonyl compounds, which have a variety of applications in synthetic organic chemistry. 相似文献
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Light‐Controlled Histone Deacetylase (HDAC) Inhibitors: Towards Photopharmacological Chemotherapy 下载免费PDF全文
Dr. Wiktor Szymanski Maria E. Ourailidou Dr. Willem A. Velema Prof. Dr. Frank J. Dekker Prof. Dr. Ben L. Feringa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(46):16517-16524
Cancer treatment suffers from limitations that have a major impact on the patient’s quality of life and survival. In the case of chemotherapy, the systemic distribution of cytotoxic drugs reduces their efficacy and causes severe side effects due to nonselective toxicity. Photopharmacology allows a novel approach to address these problems because it employs external, local activation of chemotherapeutic agents by using light. The development of photoswitchable histone deacetylase (HDAC) inhibitors as potential antitumor agents is reported herein. Analogues of the clinically used chemotherapeutic agents vorinostat, panobinostat, and belinostat were designed with a photoswitchable azobenzene moiety incorporated into their structure. The most promising compound exhibits high inhibitory potency in the thermodynamically less stable cis form and a significantly lower activity for the trans form, both in terms of HDAC activity and proliferation of HeLa cells. This approach offers a clear prospect towards local photoactivation of HDAC inhibition to avoid severe side effects in chemotherapy. 相似文献
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Willem Karel M. Brauers 《Annals of Operations Research》2013,206(1):39-58
An approach is needed to localize in an optimal way a seaport facing different indicators, criteria or objectives sometimes from different groups or individuals. The internal mechanical solution of a Ratio System, producing dimensionless numbers, is preferred to Cost-Benefit or to Weights which most of the time are used to equalize the different units. The ratio system creates the opportunity to use a second approach: a non-subjective Reference Point Theory based on the found ratios. The two approaches form a control on each other. This theory is called MOORA (Multi-Objective Optimization by Ratio Analysis). As an application a ranking is made for the best location of a new seaport or for the expansion of an existing one given a set of objectives to be fulfilled. 相似文献
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Willem Jespers Dr. Grégory Verdon Dr. Jhonny Azuaje Dr. Maria Majellaro Dr. Henrik Keränen Prof. Xerardo García-Mera Dr. Miles Congreve Dr. Francesca Deflorian Dr. Chris de Graaf Dr. Andrei Zhukov Dr. Andrew S. Doré Dr. Jonathan S. Mason Prof. Johan Åqvist Dr. Robert M. Cooke Prof. Eddy Sotelo Dr. Hugo Gutiérrez-de-Terán 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(38):16679-16686
We present a robust protocol based on iterations of free energy perturbation (FEP) calculations, chemical synthesis, biophysical mapping and X-ray crystallography to reveal the binding mode of an antagonist series to the A2A adenosine receptor (AR). Eight A2AAR binding site mutations from biophysical mapping experiments were initially analyzed with sidechain FEP simulations, performed on alternate binding modes. The results distinctively supported one binding mode, which was subsequently used to design new chromone derivatives. Their affinities for the A2AAR were experimentally determined and investigated through a cycle of ligand-FEP calculations, validating the binding orientation of the different chemical substituents proposed. Subsequent X-ray crystallography of the A2AAR with a low and a high affinity chromone derivative confirmed the predicted binding orientation. The new molecules and structures here reported were driven by free energy calculations, and provide new insights on antagonist binding to the A2AAR, an emerging target in immuno-oncology. 相似文献
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We show that any connected regular graph with d+1 distinct eigenvalues and odd-girth 2d+1 is distance-regular, and in particular that it is a generalized odd graph. 相似文献