Articles in 2016

Genetic circuits are important for synthetic biology, biochemistry and bioengineering. Now, the encapsulation of genetic circuits into liposomes has been shown to enable a more modular design, the selective isolation of reactions from the environment and from each other, and the hierarchical assembly of reaction products.

Structure-based drug design has generally focused on calculating binding free energies of protein–ligand complexes. It has now been shown that structural, rather than thermodynamic, stability — specifically, the work necessary to reach a quasi-bound state in which the ligand has just broken the most important contact with the receptor — can be calculated and used as a tool in virtual screening.

Switching the chirality of helicates non-invasively is challenging, even though helicates were discovered some decades ago. Now, by incorporating a light-driven molecular motor into a Cu(I)-helicate, the chirality of the metal helicate as well as the assembly and disassembly processes can be switched non-invasively by light and heat.

Biomolecular nanoscale compartments are ubiquitous in living systems. Although their formation is fairly straightforward, the same cannot be said of their inorganic counterparts. In this study, uniform nanoshells are observed self-assembling from stabilizer-free inorganic nanoparticles in water, under ambient conditions, and without the need for spherical tiling. This enables further study of inorganic prebiotic systems and compartmentalized biomimetic catalysis.

Despite decades of research into heme-copper oxidases, the advantages provided by copper over iron as the non-heme metal has remained unclear. Now, the preference of copper over iron has finally been explained. Copper favours faster electron transfer and higher O–O bond activation, which results in much higher oxidase activity than would be achieved by an iron equivalent.

Reversible fluorescent probes for intracellular glutathione (GSH) imaging have now been designed and synthesized based on Si-rhodamine fluorophores. These probes are shown to be capable of quantifying the GSH concentration in various living cell types and also for monitoring real-time live-cell imaging of GSH dynamics with a temporal resolution of seconds.

Ultrafast 2D Raman-THz spectroscopy has been applied to investigate the dynamics of the hydrogen-bond networks in aqueous salt solutions. It was demonstrated that the degree of inhomogeneity of the intermolecular modes of the liquid correlates with the structure-making capability of the cation.

Pentoses and hexoses represent important structural motifs in bioactive secondary metabolites, though their synthesis often requires several elongation steps. Now, a method for radical–radical coupling reactions of sugar derivatives enables the single-step preparation of the oxygenated carbon chains of several natural products, including sagittamide D, maitotoxin and hikizimycin.

A chemical proteomic strategy is described for the discovery of protein-bound electrophilic groups in human cells. Using this approach, the dynamic regulation of the pyruvoyl catalytic cofactor in S-adenosyl-L-methionine decarboxylase was characterized and an N-terminal glyoxylyl modification on secernin proteins was discovered.

Stereodynamics describes how the vector properties of molecules affect the probabilities of specific processes in molecular collisions. Measurements of irregular diffraction patterns for NO radicals colliding with rare-gas atoms reveal a previously unrecognized type of quantum stereodynamics and a ‘propensity rule’ for the magnetic quantum number (m) of the molecules.

Mechanochemically controlled polymerization is rare in polymer chemistry. Now, it has been shown that mechanical force can initiate and control the polymerization of an acrylate monomer. Piezochemical reduction of a copper(II) precursor using mechanical agitation of piezoelectric nanoparticles generates the polymerization activator required for controlled radical polymerization.

Converting CS₂ and COS pollutants into benign products is critical in eliminating waste exhaust fumes. Now, a series of air-stable palladium complexes mediate hydrolysis of both CS₂ carbon–sulfur bonds at 25 °C to produce CO₂. Oxidation of the resulting complexes regenerates the starting complexes with SO₂ and NO₂ release.

The controlled mechanical activation of specific covalent bonds is a rapidly expanding field in chemistry. Now, it is shown that disulfide bond reduction proceeds through different mechanisms depending on the external force applied. This strongly suggests that refined models should be used when interpreting mechanochemical experiments, particularly when sonication is involved.

Controlling macrocycle conformation represents a powerful tool for the construction of new bioactive molecules. Now, peptide-based macrocycles bearing a 1,3,4-oxadiazole moiety grafted into their backbone have been synthesized via a new cyclization approach. The resulting cyclic products exhibit conformationally rigid turn structures (stabilized through intramolecular hydrogen bonding) that can display passive membrane permeability.

Naturally scarce but synthetically accessible, Gauthier J.-P. Deblonde and Rebecca J. Abergel discuss element 89 and its emergence as a candidate radio-theranostic metal for cancer treatment.