ChemSystemsChem最新文献

The Front Cover illustrates a robot communicating with surrounding entities using various (chemical) signals. Not all communication and signal processing is successful, hence the slight confusion on the robot′s face. The cover alludes to the breadth of and future challenges for chemical communication within autonomous materials and robots. Cover design by Dr. Kaja Sitkowska. More information can be found in the Concept by Michael M. Lerch and co-workers.

The Cover Feature shows a Maxwell's Demon opening a trapdoor in a lipid-bilayer membrane to allow ions to move in one direction but not the other. This Concept underpins ratchet mechanisms, which have been used to develop small-molecule machines, and might soon enable the construction of artificial transmembrane pumps. More information can be found in the Concept by Stefan Borsley.

At the earliest development of prebiotic chemistry, bacterial cells were primarily viewed as “bags of molecules.” This longstanding viewpoint shaped and biased early research about life's origins, setting an initial target when considering the path from prebiotic chemistry to modern life. The two fields of systems chemistry and bacterial cell biology seem like oil and water, but each brings their own perspectives and methods to consider “what is life?”. Here, we review the most recent discoveries in bacterial cell biology, focusing on biomolecular condensates to consider how they may impact our thinking of matter-to-life transitions. The presence of condensate compartments in the bacterial domain of life strengthens the hypothesis that condensates play roles in coordinating chemical systems in life's origins. Bacterial condensates have been shown to enhance enzymatic reactions, tune substrate specificity, and be responsive to environmental conditions and metabolites. Systems chemistry studies have further illuminated the unique chemical environment within condensates and strategies for logically tying chemical processes to the formation and dissolution of condensates. We consider the potential of biomolecular condensates to provide “incubator spaces” where new chemistries can develop and examine future challenges regarding the capability of condensates to yield emergent chemical systems capable of selection.

Bio-inspired approaches in materials science and systems chemistry are yielding a variety of stimuli-responsive and dynamic materials that are gradually changing our everyday life. However, the ability to chemically program these materials to exhibit macroscopic higher-order behaviours such as self-assembly, contractility, swarming, taxis, chemical communication, or predator-prey dynamics remains an ongoing challenge. While still in its infancy, the successful fabrication of bio-inspired materials displaying higher-order behaviours not only will help bridging the gap between living and non-living matter, but it will also contribute to the development of advanced materials for potential applications ranging from tissue engineering and biotechnology, to soft robotics and regenerative medicine. Our Mini-Review will systematically discuss the higher-order behaviours developed thus far in bio-inspired systems, namely (i) polymer networks (ii) microbots, (iii) protocells, and (iv) prototissues. For each system it will provide key examples and highlight how the emergent behaviour could be chemically programmed.

The knowledge regarding the origins of life from inanimate materials is still elusive. It was proposed that biological building blocks evolved from the inorganic substances present in the early earth conditions. However, the process by which chemistry can be converted into biology has not yet been achieved in the laboratory. The artificial system in the out-of-equilibrium state must maintain a few critical features of life, like compartmentalization, metabolism, and replication, to be considered alive. In this direction, working with cysteine (Cys)-based molecules is strategic to understand the life evolution process. The presence of the sulphydryl (−SH) group in the Cys-residue can build a dynamic equilibrium state through disulfide redox chemistry under the proper guidance of oxidizing and reducing agents. In this review article, our primary focus is to discuss the Cys-containing short-peptide-based self-assembly and disassembly processes. The formation of disulfide bonds sometimes helps in the self-assembly process and gelation, but the reverse is also true in some cases. In the later part of this article, we cover the fact that these sulphydryl-based systems have shown their adaptability to mimic different life-essential criteria to participate in Darwinian evolution.

It has long been thought that abiogenesis requires a process of selection and evolution at the molecular level, but this process is hard to explore experimentally. One solution could be the use of automation in experiments which could allow for traceability and the ability to explore a larger reaction space. We report a fully programmable and automated platform to explore the reactions of amino acids in the presence of mineral environments. The robotic system is based upon the Chemputer system which has well defined modules, software, and a chemical programming language to orchestrate the chemical processes, including analysis. The reaction mixtures were analysed with tandem mass spectrometry and a peptide sequencing algorithm. Each experiment was screened for 1,398,100 possible unique sequences, and more than 550 specifically defined sequences were confirmed experimentally. This work aimed to develop a new understanding of selection in repeated cycles of polymerisation reactions to explore the emergence of well-defined amino acid sequences. We found that the outcome of oligomerisation was significantly influenced by the presence of different minerals, and that a serpentine environment selects glycine and phenylalanine rich fragments that enable the formation of longer oligomers with well-defined sequences as a function of cycle number.

Coordination of functions in multi-body or multi-component systems requires communication among its parts and is a prerequisite for achieving complex tasks. While electromagnetic (network) communication provides a key ingredient for modern robotics, its molecular equivalent is largely missing for soft robots. With advancements in programmed cargo release, DNA strand-displacement reactions, enzymatic cascades, and genetic circuits, budding solutions to such chemical network communication have emerged with the potential to drive function in soft machines. In order for such chemical communication to be useful, however, new control concepts, (orthogonal) communication protocols, and molecular solutions should be found. Herein, we provide a critical perspective on the current state-of-the-art chemical communication and identify key challenges towards autonomous soft materials, including signal processing, dealing with noise, switching signaling modalities, and limitations in time and length scales that determine material design. Building on an emerging body of examples, we illustrate gaps, synergies, and new concepts that may provide possible solutions to achieve standardized and reliable molecular information exchange for regulating (soft) robotic function.

The Front Cover illustrates the formation of a rotaxane by crown ether active template synthesis (CEATS). Depicted is the aminolysis of an activated ester, which produces a rotaxane containing an amide thread. Cover design by Anna Tanczos, Sci-Comm Studios. More information can be found in the Concept by Stephen D. P. Fielden.

The spontaneous generation of transmembrane gradients is an important fundamental research goal for artificial nanotechnology. The active transport processes that give rise to such gradients directly mirror the famous Maxwell's Demon thought experiment, where a Demon partitions particles between two chambers to generate a nonequilibrium state. Despite these similarities, discussion of Maxwell's Demon is absent in the literature on artificial membrane transport. By contrast, the emergence of rational design principles for nonequilibrium artificial molecular motors can trace its intellectual roots directly to this famous thought experiment. This perspective highlights the links between Maxwell's Demon and nonequilibrium machines, and argues that understanding the implications of this 19^th century thought experiment is crucial to the future development of transmembrane active transport processes.

Spontaneous interactions between nucleotides and lipid membranes are likely to have played a prominent role in the emergence of life on Earth. However, the effect of nucleotides on the physicochemical properties of model protocellular membranes is relatively less understood. To this end, we aimed to discern the effect of canonical nucleotides on the properties of single-chain amphiphile membranes under prebiotically relevant conditions of multiple wet-dry cycles. Furthermore, the change in the critical aggregation concentration of the membranes and their stability in the presence of nucleotides was also investigated in astrobiologically relevant analogue environments. We report that different nucleotides, lipid headgroups, and the ionic makeup of the system affect lipid-nucleotide interactions, and these, in turn, modulate the effect of nucleotides on the membrane properties. Specifically, the presence of AMP, UMP, and CMP promoted self-assembly of oleic acid membranes and increased their stability against certain prebiotically relevant selection pressures. This study takes us a step towards an appreciable understanding of how nucleotides might have shaped the protocellular landscape of the prebiotic Earth.