Journal of Systems Chemistry

http://link.springer.com/journal/13322

List of Papers (Total 36)

Transition to diversification by competition for multiple resources in catalytic reaction networks

Background All life, including cells and artificial protocells, must integrate diverse molecules into a single unit in order to reproduce. Despite expected pressure to evolve a simple system with the fastest replication speed, the mechanism by which the use of a great variety of components, and the coexistence of diverse cell-types with different compositions are achieved is as...

On the divide between animate and inanimate

Vitalism was abandoned already for a long time ago, yet the impression that animate beings differ in some fundamental way from inanimate objects continues to thrive. Here, we argue that scale free patterns, found throughout nature, present convincing evidence that this demarcation is only imaginary. Therefore, all systems ought to be regarded alike, i.e., all are consuming free...

Autocatalytic sets in E. coli metabolism

Background A central unsolved problem in early evolution concerns self-organization towards higher complexity in chemical reaction networks. In theory, autocatalytic sets have useful properties to help model such transitions. Autocatalytic sets are chemical reaction systems in which molecules belonging to the set catalyze the synthesis of other members of the set. Given an...

Cyclic growth of hierarchical structures in the aluminum-silicate system

Background Biological structures grow spontaneously from a seed, using materials supplied by the environment. These structures are hierarchical, with the ‘building blocks’ on each level constructed from those on the lower level. To understand and model the processes that occur on many levels, and later construct them, is a difficult task. However interest in this subject is...

Autocatalytic sets and boundaries

Autopoietic systems, chemotons, and autogens are models that aim to explain (the emergence of) life as a functionally closed and self-sustaining system. An essential element in these models is the notion of a boundary containing, maintaining, and being generated by an internal reaction network. The more general concept of collectively autocatalytic sets, formalized as RAF theory...

The nature and mathematical basis for material stability in the chemical and biological worlds

The conceptual divide separating the physical and biological sciences continues to challenge modern science. In this perspective it is proposed that the two sciences can be directly connected through the fundamental concept of stability. Physicochemical stability is shown to have a logical, rather than an empirical basis, and able to manifest itself in two distinct and often...

Design and synthesis of nucleolipids as possible activated precursors for oligomer formation via intramolecular catalysis: stability study and supramolecular organization

Background Fatty acid vesicles are an important part of protocell models currently studied. As protocells can be considered as pre-biological precursors of cells, the models try to contribute to a better understanding of the (cellular) origin of life and emphasize on 2 major aspects: compartmentalization and replication. It has been demonstrated that lipid-based membranes are...

Testing for adaptive signatures of amino acid alphabet evolution using chemistry space

Background Multidisciplinary consensus indicates that half of the genetically amino acids are likely to have been available on the prebiotic earth, which implies certain adaptive expectations for the relationship between those amino acids and later additions to the genetic code. Chemistry space a concept that translates molecules to corresponding points in multidimensional space...

Serial transfer can aid the evolution of autocatalytic sets

BackgroundThe concept of an autocatalytic set of molecules has been posited theoretically and demonstrated empirically with catalytic RNA molecules. For this concept to have significance in a realistic origins-of-life scenario, it will be important to demonstrate the evolvability of such sets. Here, we employ a Gillespie algorithm to improve and expand on previous simulations of...

Autocatalytic sets in a partitioned biochemical network

BackgroundIn previous work, RAF theory has been developed as a tool for making theoretical progress on the origin of life question, providing insight into the structure and occurrence of self-sustaining and collectively autocatalytic sets within catalytic polymer networks. We present here an extension in which there are two “independent” polymer sets, where catalysis occurs...

Inferring chemical reaction patterns using rule composition in graph grammars

Background Modeling molecules as undirected graphs and chemical reactions as graph rewriting operations is a natural and convenient approach to modeling chemistry. Graph grammar rules are most naturally employed to model elementary reactions like merging, splitting, and isomerisation of molecules. It is often convenient, in particular in the analysis of larger systems, to...

Systems chemistry: using thermodynamically controlled networks to assess molecular similarity

Background The assessment of molecular similarity is a key step in the drug discovery process that has thus far relied almost exclusively on computational approaches. We now report an experimental method for similarity assessment based on dynamic combinatorial chemistry. Results In order to assess molecular similarity directly in solution, a dynamic molecular network was used in...

On the propagation of a conceptual error concerning hypercycles and cooperation

The hypercycle is a system of replicators, whose members are auto- and cross-catalytic: replication of each member is catalyzed by at least one other member of the system. Therefore, the kinetics of growth of every member is at least second order. In ecology such systems are called mutualistic whose members are cooperating with each other. The dynamics of such systems are...

A formal model of autocatalytic sets emerging in an RNA replicator system

BackgroundThe idea that autocatalytic sets played an important role in the origin of life is not new. However, the likelihood of autocatalytic sets emerging spontaneously has long been debated. Recently, progress has been made along two different lines. Experimental results have shown that autocatalytic sets can indeed emerge in real chemical systems, and theoretical work has...

Pathway control in the self-construction of complex precipitation forms in a Cu(II)-oxalate system

Background Many biological systems contain complex precipitation patterns. These structures are considered to be the result of finely tuned and genetically encoded developmental pathways. The amount of encoded information needed to generate and manipulate these structures is poorly understood. Investigating the dynamics of spontaneous pattern formation in non-biological systems...

Autocatalytic sets extended: Dynamics, inhibition, and a generalization

Background Autocatalytic sets are often considered a necessary (but not sufficient) condition for the origin and early evolution of life. Although the idea of autocatalytic sets was already conceived of many years ago, only recently have they gained more interest, following advances in creating them experimentally in the laboratory. In our own work, we have studied autocatalytic...

Suitable energetic conditions for dynamic chemical complexity and the living state

Any living organism can be considered as a component of a dissipative process coupling an irreversible consumption of energy to the growth, reproduction and evolution of living things. Close interactions between metabolism and reproduction are thus required, which means that metabolism has two main functions. The first one, which is the most easily perceptible, corresponds to the...

The eightfold path to non-enzymatic RNA replication

The first RNA World models were based on the concept of an RNA replicase - a ribozyme that was a good enough RNA polymerase that it could catalyze its own replication. Although several RNA polymerase ribozymes have been evolved in vitro, the creation of a true replicase remains a great experimental challenge. At first glance the alternative, in which RNA replication is driven...

Maximizing output and recognizing autocatalysis in chemical reaction networks is NP-complete

Background A classical problem in metabolic design is to maximize the production of a desired compound in a given chemical reaction network by appropriately directing the mass flow through the network. Computationally, this problem is addressed as a linear optimization problem over the flux cone. The prior construction of the flux cone is computationally expensive and no...

Exploding vesicles

While studying fatty acid vesicles as model primitive cell membranes, we encountered a dramatic phenomenon in which light triggers the sudden rupture of micron-scale dye-containing vesicles, resulting in rapid release of vesicle contents. We show that such vesicle explosions are caused by an increase in internal osmotic pressure mediated by the oxidation of the internal buffer by...

Enzymatic synthesis of DNA employing pyrophosphate-linked dinucleotide substrates

Background One of the remaining questions in the understanding of the origin of Nature's information system is the way the first nucleic acids have been synthesized. This could have been realized using nucleoside triphosphates or imidazolides of nucleoside monophosphates as building blocks. Alternatively, dinucleoside pyrophosphates could have been used for this purpose. The...

A stochastic model of the emergence of autocatalytic cycles

Autocatalytic cycles are rather common in biological systems and they might have played a major role in the transition from non-living to living systems. Several theoretical models have been proposed to address the experimentalists during the investigation of this issue and most of them describe a phase transition depending upon the level of heterogeneity of the chemical soup...

Toward a general theory of evolution: Extending Darwinian theory to inanimate matter

Though Darwinian theory dramatically revolutionized biological understanding, its strictly biological focus has resulted in a widening conceptual gulf between the biological and physical sciences. In this paper we strive to extend and reformulate Darwinian theory in physicochemical terms so it can accommodate both animate and inanimate systems, thereby helping to bridge this...

The relationship between difference and ratio and a proposal: Equivalence of temperature and time, and the first spontaneous symmetry breaking

The mathematical form of the energy-entropy relationship is that of the relationship between the difference and the ratio of any two 'entities' x and y creating a geometrical 3D projection x = y·z, i.e., a surface of the shape of a hyperbolic paraboloid being a particular form of a quadric. The significance of this relationship is discussed here in a realm beyond thermodynamics...

Unravelling a fulvene based Replicator: Experiment and Theory in Interplay

A self-replicating system based on a cycloaddition of a fulvene derivative and a maleinimide is investigated using a two-pronged approach combining NMR spectroscopy with computer simulations. In the course of the reaction, two diastereomers are formed with identical rates in the absence of replication. When replication is enabled, a network emerges in which one diastereomer takes...