Reviews & Analysis

Ribonucleoprotein granules are ubiquitous in living organisms with the protein and RNA components having distinct roles. In the absence of proteins, RNAs are shown to undergo phase separation upon heating. This transition is driven by desolvation entropy and ion-mediated crosslinking and is tuned by the chemical specificity of the RNA nucleobases.

To develop covalent inhibitors with high potency and low off-target effects, combinatorial approaches that search for candidates from large libraries are desired. Here, sulfur(VI) fluoride exchange (SuFEx) in vitro selection is established for the evolution of covalent aptamers from trillions of SuFEx-modified oligonucleotides. Through this technique, covalent aptamers with optimally balanced selectivity and reactivity are identified.

Aromatic oligoamide macrocycles have been developed in which the constrained backbone enforces hydrogen-bond donors to orient towards the macrocycle centre, forming a highly electropositive cavity. These macrocycles show strong binding for various anions and can partition into biomembranes to facilitate selective transmembrane anion transport.

An infrared laser-induced temperature jump provides a rapid and broadly applicable perturbation to protein dynamics. Temperature-jump crystallography was paired with time-resolved X-ray crystallography to study the dynamic enzyme lysozyme. Measurements with and without a functional inhibitor revealed different patterns in the propagation of motion throughout the enzyme.

Experimental and computational studies establish the operation of Fe(iii)-based metalloradical catalysis for the asymmetric cyclopropanation of alkenes with different classes of diazo compounds. The reaction proceeds through a stepwise radical mechanism involving α-Fe(iv)-alkyl and γ-Fe(iv)-alkyl radical intermediates. This work provides a future direction for the development of metalloradical catalysis.

Radiation damage in biological systems by radicals and low-energy electrons formed from water ionization is a consequence of ultrafast processes that follow core-level ionization of hydrated metal ions. More details of the complex pathway are now revealed from the study of aluminium-ion relaxation through sequential electron-transfer-mediated decay.

A multimodal imaging approach is developed to interrogate microorganism–semiconductor biohybrids at the single-cell and single-molecule level for light-driven CO₂ fixation. Application to lithoautotrophic bacterium Ralstonia eutropha biohybrids reveals the roles of two hydrogenases in electron transport and bioplastic formation, the magnitude of semiconductor-to-single-cell electron transport and the associated pathways.

Despite advances, understanding of the quantum state-to-state scattering dynamics between charged ions and neutral molecules at low collision energies remains limited. A high-resolution crossed-beam experiment with quantum state-selected ions prepared by laser photoionization and supporting trajectory surface-hopping calculations now provides insight into the quantum state-to-state collisional dynamics of a model charge-transfer reaction.

Challenges in the synthesis of heparan sulfate (HS) glycosaminoglycans have limited access to defined HS oligosaccharides bearing a diverse array of sulfation sequences. A concise, divergent synthetic approach now provides a library of 64 HS tetrasaccharides displaying a comprehensive set of sulfation sequences, offering insight into the elusive sulfation code of glycosaminoglycans.

Protein translation is the ultimate paradigm for sequence-defined polymer synthesis. To introduce non-canonical monomers into the genetic code of living organisms, pairs of biomolecules known as aminoacyl-tRNA synthetases (aaRSs) and transfer RNAs (tRNAs) are required. The discovery and engineering of five such pairs, that do not interfere with each other or the aaRS–tRNA pairs of a bacterial host, sets the stage for highly modified genetically encoded biopolymers.

Low-coordinate lanthanide complexes with strong magnetic anisotropy could afford high-performance single-molecule magnets (SMMs) but are challenging to synthesize. Now, through ligand design, a near-linear pseudo-two-coordinate Yb(iii) complex that exhibits slow magnetic relaxation is reported. The complex has a large total splitting of the ground-state manifold, arising from the crystal field imposed by the ligands.

Colloidal clathrate crystals self-assembled from hard polyhedral shapes in computer simulations are stabilized by entropy compartmentalization, whereby hosts and guests contribute unequally to the entropy. This creative solution to satisfying the laws of thermodynamics suggests new ways to make colloidal crystals with open cages and hierarchical host–guest structures.

Catenanes that are chiral owing to the relative orientation of their rings have always been referred to as ‘topologically chiral’. It is now shown that although in specific cases the stereochemistry is a topological property of the structure, the underlying stereogenic unit itself is not inherently topological in nature.

Serial rotation electron diffraction (SerialRED) enables rapid and reliable phase analysis and structure determination of complex polycrystalline materials that cannot be routinely characterized using X-ray diffraction. Five zeolite phases were identified in a single synthesis product by automated screening of hundreds of crystals, demonstrating the power of SerialRED for materials development.

Nanomachines are central to life and are becoming an important part of self-regulated nanotechnologies. Inspired by natural self-assembled nanosystems, it has been shown that artificial nanosystems can evolve and adopt regulatory functions upon fragmentation of their structures into multiple components that reassemble to form the same nanostructure.