Selective desolvation in two-step nucleation mechanism steers crystal structure formation

Illustrated is a two-step nucleation process, where solute molecules in the solution are first partially desolvated to form locally dense liquid clusters followed by selective desolvation to yield crystalline solids.

Spontaneous nucleation and fast aggregate-dependent proliferation of α-synuclein aggregates within liquid condensates at physiological pH

It is well-established that α-synuclein aggregation may proceed through an initial lipid-dependent aggregate formation and, if at acidic pH, a subsequent aggregate-dependent proliferation. It has also been recently reported that the aggregation of α-synuclein may also take place through an alternative pathway, which takes place within dense liquid condensates produced through liquid-liquid phase separation. The microscopic mechanism of this process, however, remains to be clarified. Here, we developed a fluorescence-based assay to perform a kinetic analysis of the aggregation process of α-synuclein within liquid condensates, and applied it to determine the corresponding mechanism of aggregation. Our analysis shows that at pH 7.4 the aggregation process of α-synuclein within dense condensates starts with spontaneous primary nucleation followed by rapid aggregate-dependent proliferation. Taken together, these results reveal a highly efficient pathway for the appearance and proliferation of α-synuclein aggregates at physiological pH.

Thermomechanically active electrodes power work-dense soft actuators

The effect of chain extender structure and composition on the properties of liquid crystal elastomers (LCE) is presented. Compositions are optimized to design work-dense liquid metal LCE composites that are operated with 100 mW power.

Widespread occurrence of the droplet state of proteins in the human proteome

A wide range of proteins have been reported to condensate into a dense liquid phase, forming a reversible droplet state. Failure in the control of the droplet state can lead to the formation of the more stable amyloid state, which is often disease-related. These observations prompt the question of how many proteins can undergo liquid–liquid phase separation. Here, in order to address this problem, we discuss the biophysical principles underlying the droplet state of proteins by analyzing current evidence for droplet-driver and droplet-client proteins. Based on the concept that the droplet state is stabilized by the large conformational entropy associated with nonspecific side-chain interactions, we develop the FuzDrop method to predict droplet-promoting regions and proteins, which can spontaneously phase separate. We use this approach to carry out a proteome-level study to rank proteins according to their propensity to form the droplet state, spontaneously or via partner interactions. Our results lead to the conclusion that the droplet state could be, at least transiently, accessible to most proteins under conditions found in the cellular environment.

Synthesis of high-titer alka(e)nes in Yarrowia lipolytica is enabled by a discovered mechanism

Alka(e)nes are ideal fuel components for aviation, long-distance transport, and shipping. They are typically derived from fossil fuels and accounting for 24% of difficult-to-eliminate greenhouse gas emissions. The synthesis of alka(e)nes in Yarrowia lipolytica from CO2-neutral feedstocks represents an attractive alternative. Here we report that the high-titer synthesis of alka(e)nes in Yarrowia lipolytica harboring a fatty acid photodecarboxylase (CvFAP) is enabled by a discovered pathway. We find that acyl-CoAs, rather than free fatty acids (FFAs), are the preferred substrate for CvFAP. This finding allows us to debottleneck the pathway and optimize fermentation conditions so that we are able to redirect 89% of acyl-CoAs from the synthesis of neutral lipids to alka(e)nes and reach titers of 1.47 g/L from glucose. Two other CO2-derived substrates, wheat straw and acetate, are also demonstrated to be effective in producing alka(e)nes. Overall, our technology could advance net-zero emissions by providing CO2-neutral and energy-dense liquid biofuels.