Chemistry
The de novo design of a protein capable of binding a cofactor in a unique orientation is a challenging problem because a range of structurally similar, yet different, complexes are often formed. Now, a team led by former graduate student Nick Polizzi and by Professors David N. Beratan and Michael J. Therien at Duke, and by Professor William F. DeGrado at UCSF, report a protein — designed entirely from first principles — that binds a small-molecule cofactor in a unique and precisely predetermined… read more about Beratan, Therien and Collaborators Pack a Porphyrin into a Protein Puzzle »
The Malcolmson lab has reported a new class of reagents, 2-azadienes, for the catalytic enantioselective construction of chiral amines. The 2-azadienes demonstrate reverse polarity (umpolung) of an enamine, facilitating catalytic addition of a nucleophile to its N-b-carbon and subsequent stereoselective electrophile trap at the a-carbon. In this work, they illustrate the power of these reagents in reductive couplings with ketones for chemo-, diastereo-, and enantioselective preparation of 1,2-amino tertiary… read more about Malcolmson Lab Discloses New Reagent for Enantioselective Amine Synthesis »
Biology is well known to manipulate energy using proton-coupled electron transfer and phosphorylation reactions. It was found recently that energy conversion can also occur via a new class of reactions, known as electron bifurcation reactions. Remarkably, these reactions send one electron “uphill” and one “downhill,” enabling the overall reaction to satisfy the demands of thermodynamics. Jonathon Yuly, a graduate student working with Profs. Zhang and Beratan in the… read more about Beratan Group Explains New Class of Electron Bifurcation Reactions »
The Wang, Malcolmson and Warren labs have teamed up to use diazirines as molecular imaging tags for biomedical applications. Diazirines are an attractive class of potential molecular tags for magnetic resonance imaging with their biocompatibility and ease of incorporation into a large variety of molecules. The team has recently demonstrated with a 15N2-diazirine-containing choline derivative that 15N2-diazirines are capable of supporting long-lasting polarization, … read more about Wang, Malcolmson and Warren Labs Promoting Hyperpolarization of 15N2-Diazirines for Novel NMR/MR Imaging Strategies »
Equilibrating glass-forming liquids is notoriously hard; Duke chemists and their collaborators in France have developed a way to circumvent this obstacle, enabling studies of extremely sluggish liquids. The results were just published in Proceedings the National Academy of Sciences and Physical Review Letters. The latter paper was also featured in Physics Synopsis and you can learn more on the Duke Research Blog. read more about Charbonneau Lab and Collaborators Cheat Time »
A recent publication in Nature Communications on selective carbon dioxide hydrogenation using plasmonic rhodium catalysts by the Liu lab and collaborators has been selected as one of eight featured articles in the Nature Research “Understanding Catalysis” collection. In preparation for the launch of Nature Catalysis, a new online-only journal in the Nature family, this specially curated collection brings together recent work that offer new understandings into… read more about Recent Liu Lab Work Selected for Nature Research “Understanding Catalysis” Collection »
The Hargrove Lab compared bioactive ligands that target RNA to current FDA-approved drugs, nearly all of which target proteins. With the help of the Beratan Lab, they identified key differences in physical, structural, and spatial properties that distinguish RNA-targeted bioactive ligands. These unique insights are expected to facilitate the selection and synthesis of RNA-targeted libraries with the goal of efficiently identifying selective small molecule ligands for therapeutically relevant RNAs. Read more about… read more about Hargrove Lab Discovers Distinctive Properties of RNA-targeted Chemical Probes »
The Therien Lab, teamed with chemists at UC San Francisco, have created a synthetic protein that tightly binds a non-biological catalyst, a type of molecule called porphyrin that is capable of stealing electrons from other molecules when it absorbs light. Read more about how the “protein gator” chomps porphyrin cofactors in the Nature Chemistry article available here. read more about Therien Lab Solving Protein Design Puzzle One Chomp at a Time »
A recent molecule, Takinib, developed by the Derbyshire and Haystead's labs, has been found to induce cell death in cancer cells by inhibiting the enzyme TAK-1. Current testing is focused on Takinib’s possible therapeutic benefits in rheumatoid arthritis and could potentially expand to focus on other diseases, such as malaria. Read more about this exciting molecule in the recent edition of Cell Chemical Biology. read more about Derbyshire Lab and Pharmacology Collaborators Spur Cell Death in Tumors »
The Welsher Lab has created a 3D Virus Cam that can track particles that are faster moving and less bright than previous microscopes. This new development provides a robust method for real-time 3D tracking of fast and lowly emitting particles, based on a single excitation and detection pathway, paving the way to more widespread application to relevant biological problems. Learn more about the Welsher Lab's "virus camera" in the recent issue of Optics Letters, available here or watch as it… read more about Welsher Lab Builds 3D Virus Camera »
The development of reactions that transform cheap and readily accessible materials to high-value products with minimal waste is an important objective in chemical synthesis. Enantioselective intermolecular olefin hydrofunctionalizations meet these criteria but are rare. The Malcolmson lab has reported the first examples of late transition metal-catalyzed enantioselective intermolecular hydroamination of olefins with aliphatic amines. A range of acyclic 1,3-dienes undergo reaction with several amines in the… read more about Malcolmson Lab Reports Catalytic Enantioselective Intermolecular Hydroamination »
The transformation of the free-energy landscape from smooth to hierarchical in glassy materials can significantly impact their low-temperature properties. With 30 pages of handwritten calculations Sho Yaida, a Duke postdoctoral fellow in the Charbonneau lab, has laid to rest a 30-year-old mystery about the nature of this transformation. The work was just published in Physical Review Letters. Learn more on Duke TODAY. read more about 30-year-old Mystery on the Glass Problem Demystified »
A cartilage-mimicking material created by the Wiley Lab may one day allow surgeons to 3-D print replacement knee parts that are custom-shaped to each patient’s anatomy. Feichen Yang, a graduate student in the Wiley lab, experimented with mixing together two different types of hydrogels -- one stiffer and stronger, and the other softer and stretchier -- to create what is called a double-network hydrogel. By changing the relative amounts of the two hydrogels, Yang could adjust the strength and elasticity of… read more about Printable Hydrogel Matches the Strength and Elasticity of Human Cartilage »
The reliance on heated catalysts to overcome high activation energies and achieve practical reaction rates in industrial scale catalysis not only requires high thermal energy inputs but also shortens catalyst lifetime. By comparing light and dark conditions on rhodium catalysts in carbon dioxide hydrogenation, the Liu lab, together with Dr. Henry Everitt at the Army Aviation & Missile RD&E Center and Yang group in our department, has shown how the plasmonic behavior of rhodium nanoparticles profoundly improves their… read more about Lighting the Path Towards Selective Carbon Dioxide Hydrogenation »
USB flash drives are already common accessories in offices and college campuses; but thanks to the rise in printable electronics, digital storage devices like these may soon be everywhere – including on our groceries, pill bottles and even clothing. The Wiley Lab has brought us closer to a future of low-cost, flexible electronics by creating a new “spray-on” digital memory device using only an aerosol jet printer and nanostructure inks. The device, which is analogous to a 4-bit flash drive, is the first… read more about Wiley Lab Develops Spray-On Memory for Digital Storage »
The high temperatures (>200 °C) required to melt silver nanoparticle inks together to make conductive lines has limited the development of printed electronic devices, such as RFID tags, on low-cost, heat-sensitive paper and plastic substrates. By comparing the resistivity of films made from silver nanostructures with different shapes, the Wiley lab has shown that films of silver nanowires are 4000 times more conductive than the conventionally used silver nanoparticles after drying. In fact, films of silver… read more about Shape Matters for Printed Electronics »
The Hargrove Lab has demonstrated that small molecule ligands can be used to classify RNA secondary structures through shape-based discrimination and that topology is an essential component for selective binding of RNA by small molecules. Read more in the Journal of the American Chemical Society. read more about Hargrove Lab Uses Pattern Recognition to Discriminate RNA Secondary Structure with Small Molecules »
The Fitzgerald group and their collaborators at the National Institute of Environmental Health Sciences find that house dust mite allergens are more thermodynamically stable and more abundant than non-allergens in the dust mite proteome. Read more about their discovery in Duke Today and also see their paper published in the Journal of Allergy and Clinical Immunology. read more about Fitzgerald Group Characterizes Dust Mite Allergens with SPROX Methodology »
Most solid materials are amorphous. Although the behavoir of these materials is anomalous when compared to crystalline solids, the origin of the difference has long been a source of confusion. The Charbonneau group and collaborators have recently found evidence for an exotic phase transition that might underlie the effect. The results appear in the Proceedings of the National Academy of Sciences, USA. read more about Gardner Gathers Glasses »
Professor Beratan’s group has just reported a new mechanism for spin-forbidden excitation energy transfer, a process of great significance in solar photochemistry. The group finds that spin forbidden electronic energy transfer, known as Dexter energy transfer, may be mediated by excited states of the bridge linking an electronically excited donor to an acceptor group (indicated by the blue and green squares in the diagram), rather than by charge-transfer states of the system (indicated by the gray and oranges… read more about Solar Photochemistry Breakthrough Reported by Beratan Group »
A theoretical-experiemental collaboration between David Beratan’s group at Duke University and Nongjian Tao’s group at Arizona State University has established and validated an approach to control the wave-like characteristics of electrons as they move through DNA. A paper just posted online at Nature Chemistry - and highlighted in a Duke News article - describes strategies to sustain coherent or wave-like DNA charge transport on the the length of multiple nanometers in soft-wet self-assembled matter. … read more about Beratan and Collaborators show how DNA sequences turn molecules into electron highways »
An article in Science by Prof. Agostino Migliore and collaborators reports the design of robust (opto)electronicmolecular switches. The experiments demonstrate reversible, stable and reproducible electrical switching of single molecules linked to graphene electrodes. The theoretical analysis reveals the chemical-physical underpinnings of photoinduced and temperature-dependent mechanisms for the observed switching. This work provides unambiguous evidence that molecules with suitable electronic properties and engineered… read more about Breakthrough in Nanoelectronics: Design of Robust Molecular Switches »
A recent article by Prof. Alvin Crumbliss in Nautilus focuses on the metallome, a collection of metal atoms that helped shape modern biology and impacted evolution. For more on how the metallome changed cellular chemistry, please see the article available here. read more about Crumbliss Rocks with Heavy Metal(s) »
Yuan Zhuang from the Charbonneau group has recently made a breakthrough in the description of periodic microphases. This advance enables the determination of phase diagrams for models that can form cluster crystals, double gyroid, lamellae, and other complex mesoscale assemblies. The results appear in Physical Review Letters. read more about Charbonneau Lab Makes Breakthrough in Periodic Microphases »
In a collaborative and highly interdisciplinary effort, the Wang, Warren, Malcolmson, Blum, and Theis labs have disclosed a new class of molecules that may be used as biomolecular tags for MRI, potentially enabling metabolic processes to be viewed in real time. The work, published in the journal Science Advances and highlighted in Duke Today, details the hyperpolarization of these molecules through an iridium-catalyzed spin-polarization transfer from singlet-state hydrogen gas, increasing NMR signals, which… read more about Interdisciplinary Efforts Lead to Imaging Tag for MRI »
Charbonneau and collaborators have recently made the stunning prediction that, upon cooling, simple glass-forming liquids can form two different types of amorphous solids. This work and the broader scientific context for this fundamental advance is featured this month in the French popular science magazine, La Recherche. A link to the article, though in French, may be found here: http://www.larecherche.fr/mensuel/510 read more about Charbonneau's Glass-Forming Liquids Featured in La Recherche »
The Hargrove lab discusses progress towards the molecular characterization of long noncoding RNAs (lncRNAs), a relatively new class of biomacromolecules implicated in a wide range of biological processes and human diseases. Despite the widely-recognized importance of lncRNAs, biochemical and biophysical studies are still in early stages. This Current Topics article in Biochemistry describes and analyzes the techniques currently in use to study the structure, interactions, and functions of lncRNAs as… read more about Connecting long noncoding RNA structures and biochemical functions to disease »
The Derbyshire Lab reports the discovery of inhibitors that target multiple stages of malaria parasite growth. To identify these inhibitors Derbyshire took advantage of the TCAMS small molecule library, which is comprised of diverse and potent chemical scaffolds with activities against malaria's blood stage and investigated their effects against malaria's elusive liver stage using a forward chemical screen. More on their recent developments may be found here in Antimibrobial Agents and Chemotherapy… read more about Derbyshire Lab Targets Malaria »
Researchers in the Franz lab have built a peptide that binds one kind of metal ion with greater ease if it binds a different type of metal ion first. This unique example of cooperative, heterometallic allostery in a biologically compatible construct suggests the possibility of designing conditionally active metal-binding agents that could respond to dynamic changes in cellular metal status. Read more here: http://pubs.rsc.org/en/content/articlelanding/2015/SC/C5SC00602C#!divAbstract read more about Bind One Get One Free »
A new review from the McCafferty lab focuses on KDM1 class lysine demethylases. These enzymes are integrally involved in many biological processes and diseases and are therefore promising therapeutic targets. The comprehensive review describes the unique structure and substrate specificity of these enzymes, as well as current efforts toward inhibitor development. It further explores the regulation of KDM1 function through the formation of multiprotein complexes. Read more here, in the special issue of Biopolymers… read more about Reviewing the Complex Worlds of Lysine Demethylation »