Volume 9 Issue 8, August 2017

Intracellular protein delivery has been a major challenge in the field of cell biology for decades. Engineering such delivery is a key step in the development of protein- and antibody-based therapeutics. Now, two different approaches that enable the delivery of antibodies and antibody fragments into the cytosol have been developed.

The flow of energy in Earth's primary light harvesters — photosynthetic pigment–protein complexes — needs to be heavily regulated, as the sun's energy supply can vary over many orders of magnitude. Observing hundreds of individual light-harvesting complexes has now provided important insights into the machinery that regulates this process.

Recent years have witnessed a surge of interest in targeted covalent inhibition of disease-associated proteins. Among the electrophiles used to interact with nucleophilic residues in protein structures, boron is unique for its chameleonic ability to display a range of coordination modes upon interaction with protein targets.

Main-chain polymetallocenes are typically static in nature due to strong metal–ligand bonding. Now, it has been shown that such polymers based on nickelocene are dynamic due to weaker nickel–cyclopentadienyl interactions, and at low concentration or at elevated temperature, depolymerization to the moderately strained monomer occurs.

The trapping of antibodies in endosomes often limits their use for intracellular targeting. Now, a single amino acid substitution on a spider-venom peptide has been shown to attenuate the cell membrane lytic activity and enables the selective rupturing of endosomal membranes. The peptide can be used to facilitate the escape of antibodies from endosomes into the cytosol.

Delivery of antibodies into living cells enables the labelling and manipulation of intracellular antigens; however, transporting antibodies into the cytosol in a functional state is difficult. Now, a modular strategy for creating cell-permeable nanobodies capable of targeting intracellular antigens has been developed. The cell-permeable nanobodies are formed by site-specific attachment of cyclic arginine-rich cell-penetrating peptides to camelid-derived single-chain antibody fragments.

Photoprotection is crucial for the fitness of organisms that carry out oxygenic photosynthesis. LHCSR, a photosynthetic light-harvesting complex, has been implicated in photoprotection in green algae and moss. Now, single-molecule studies of LHCSR have revealed that multi-timescale protein dynamics underlie photoprotective dissipation of excess energy.

Ligand development underlies many advances in Pd-catalysed cross coupling but has seen limited application in the growing field of Ni catalysis. Now, a phosphine framework is shown to enable Ni-catalysed Suzuki coupling of acetals. Parameterization studies provide structural insight into ligand success and a quantitative model to facilitate further ligand design.

A scalable, one-pot, solution-based protocol for the controlled synthesis of uniform non-spherical block copolymer micelles is a desirable but challenging target. Now, a polymerization-induced crystallization-driven self-assembly process has been developed that offers facile access to 1D and platelet micelle morphologies and to near monodisperse cylinders of controlled length.

The biomimetic syntheses of bipleiophylline, one of the most complex monoterpene indole alkaloids, and voacalgine A, its biosynthetic precursor, have been achieved from pleiocarpamine starting material. The development of a divergent oxidative coupling for the formation of the benzofuro[2,3-b]indolenine and isochromano[3,4-b]indolenine moieties was key to this accomplishment.

Di- and tripeptide building blocks in which the C-terminus has been converted into an aldehyde are shown to form dynamic chemical networks through imine condensation followed by the formation of cyclic N,N-acetals. The networks exhibit multi-phase growth of prion-like assemblies that template the formation of chain-length-specific peptide-like oligomers.

Simple peptides are shown to assemble into well-defined amyloid phases with paracrystalline surfaces that can catalyse reactions in an enantioselective manner. Modifying individual amino acids in the building blocks enables the structure of the assembled aggregates, and the reactions that they can catalyse, to be controlled predictably.

Converting oxygen-rich biomass into fuels requires the removal of oxygen groups through hydrodeoxygenation. MoS₂ monolayer sheets decorated with isolated Co atoms bound to sulfur vacancies in the basal plane have now been synthesized that exhibit superior catalytic activity, selectivity and stability for the hydrodeoxygenation of 4-methylphenol to toluene when compared to conventionally prepared materials.

Many properties of polymers are dictated by topology. However, the topology of a macromolecule is typically a static feature after synthesis. Now, an approach to dynamic and transformable macromolecular architecture has been developed. When triggered by an external stimulus, macromolecular topology can be triggered to transform via thermodynamic control.

Although DNA nanotechnology has found many applications in developing functional structures, there has never been an independent device contained within a 3D crystal. Now, a self-assembled three-state device that can change the colour of its crystal by diffusion of DNA-ligated dyes has been reported, representing the potential to develop programmable nanomechanical devices.

Adrian Dingle tells the story of how the name of element 109 represents the lasting recognition that one of the greatest nuclear physicists was in danger of never receiving.