DOI: 10.1002/chem.201201974 Energy Propagation Through a Protometabolism Leading to the Local Emergence of Singular Stationary Concentration Profiles Matthieu Emond, [a] Thomas Le Saux, [a, b] Jean-Francois Allemand, [c] Philippe Pelupessy, [d] Raphal Plasson, [e, f] and Ludovic Jullien* [a, b] Introduction Life requires a source of energy to persist. For example, in photosynthesis, which relies on light, long-lived charge sepa- ration in photoactive transducers is primarily coupled with vectorial proton translocation across a membrane. Then the photogenerated electrochemical proton gradient is used by ATP-synthase as a secondary free energy source for ATP synthesis. [1] Thanks to enzymatic transducers, ATP hydroly- sis subsequently drives the endergonic chemical reactions of the whole metabolism. Such biological energy-transfer chains are highly efficient for preventing the dissipation of energy as heat. However, they require rather demanding components and organizations (protein transducers, cell compartmentalization). In an evolutionary perspective and for further applicative developments, it is meaningful to ad- dress the issue of their onset as well as the interplay existing between their function and their spatial organization. From the latter point of view, it has been argued that the reverse principle could interpret the emergence, organiza- tion, and persistence of life on Earth. [2, 3] Life, and in particu- lar core biochemistry, could have acted as a relaxation chan- nel that was driven into existence by primordial energy sour- ces. Beyond previous achievements still involving biological components, [4] we here experimentally implement this pro- posal for the first time in an abiotic context. A simple design is introduced to govern a highly significant (but chemically rather unusual) feature of living systems, that is, energy flows through reactive cycles [2, 3] leading to spatial dy- namic self-organization. [5] Although without metabolic clo- sure (because it relies on preexisting non-self-synthesized compounds [6] ) the present protometabolism consumes, prop- agates, and uses energy for organizational purposes. These features are realized by the photocontrol of nonho- mogeneous spatial concentration profiles of protons, a ubiq- uitous catalyst of chemical processes. [7, 8] We applied a pat- terned illumination to a solution of a reversible photoacid that becomes more acidic upon light absorption. [9, 10] To [a] Dr. M. Emond, Dr. T. Le Saux, Prof. L. Jullien École Normale SupØrieure, DØpartement de Chimie UMR CNRS-ENS-UPMC 8640 PASTEUR 24, rue Lhomond, 75231 Paris Cedex 05 (France) E-mail: Ludovic.Jullien@ens.fr [b] Dr. T. Le Saux, Prof. L. Jullien UniversitØ Pierre et Marie Curie Paris 06 4, place Jussieu, 75252 Paris Cedex 05 (France) [c] Prof. J.-F. Allemand Laboratoire de Physique Statistique École Normale SupØrieure, CNRS UMR8550, UPMC U. Paris Diderot, 24 rue Lhomond 75005 Paris (France) [d] Dr. P. Pelupessy DØpartement de Chimie École Normale SupØrieure, UMR CNRS-UPMC-ENS 7203 24, rue Lhomond, 75231 Paris Cedex 05 (France) [e] Dr. R. Plasson IRIDIA, UniversitØ Libre de Bruxelles 50, Av. F. Roosevelt, CP 194/6 1050 Brussels (Belgium) [f] Dr. R. Plasson Current address: Dept. Earth and Planetary Sciences, Harvard University 100 Edwin H. Lane Bvd, Cambridge MA 02142 (USA) Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/chem.201201974. Abstract: Living systems rely on chains of energy transfer from an energy source to maintain their metabolism. This task requires functionally identi- fied components and organizations. However, propagation of a sustained energy flux through a cascade of reac- tion cycles has never been reproduced at a steady state in a simple chemical system. By using energy patterning and a diffusing hub reactant, we achieved the transfer of energy through an abio- tic protometabolism. Patterned illumi- nation was applied to a liquid solution of a reversible photoacid. It resulted in the local onset of a proton pump, which subsequently drove an extended reaction–diffusion cycle that involved pH-sensitive reactants. Thus, light has been used for locally setting out of chemical equilibrium a reaction involv- ing “blind” reactants. The spontaneous onset of an energy-transfer chain nota- bly drives the local generation of singu- lar dissipative chemical structures; con- tinuous matter fluxes are dynamically maintained at boundaries between spa- tially and chemically segregated zones, in the absence of any membrane or predetermined material structure. Keywords: chemical evolution · coupled reactions · dissipative proc- esses · free-energy transduction · photogenerated gradients · proton pumps Chem. Eur. J. 2012, 00,0–0  2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim These are not the final page numbers! ÞÞ &1& FULL PAPER