Descripción del proyecto
El origen cósmico de la homoquiralidad biológica
Los objetos son quirales cuando no pueden superponerse a sus imágenes especulares. Las dos formas de una molécula quiral tienen idénticas propiedades físicas y químicas, pero pueden interactuar con otras moléculas quirales de manera diferente. En un estudio reciente, se ha demostrado que la unidad quiral del ARN (la ribosa) se forma en condiciones cometarias simuladas, lo que proporciona pruebas de la accesibilidad de los precursores del material genético en entornos interestelares. La homoquiralidad, que hace referencia a la uniformidad de la quiralidad, puede producirse cuando las biomoléculas quirales se sintetizan de forma asimétrica mediante la interacción con fotones polarizados circularmente en el espacio interestelar. El equipo del proyecto A-LIFE, financiado con fondos europeos, simulará las etapas evolutivas de la Tierra primitiva para demostrar cómo las moléculas heterogéneas producidas por el impacto de un meteorito se agrupan en prebiopolímeros homoquirales.
Objetivo
What is responsible for the emergence of homochirality, the almost exclusive use of one enantiomer over its mirror image? And what led to the evolution of life’s homochiral biopolymers, DNA/RNA, proteins and lipids, where all the constituent monomers exhibit the same handedness?
Based on in-situ observations and laboratory studies, we propose that this handedness occurs when chiral biomolecules are synthesized asymmetrically through interaction with circularly polarized photons in interstellar space. The ultimate goal of this project will be to demonstrate how the diverse set of heterogeneous enantioenriched molecules, available from meteoritic impact, assembles into homochiral pre-biopolymers, by simulating the evolutionary stages on early Earth. My recent research has shown that the central chiral unit of RNA, ribose, forms readily under simulated comet conditions and this has provided valuable new insights into the accessibility of precursors of genetic material in interstellar environments. The significance of this project arises due to the current lack of experimental demonstration that amino acids, sugars and lipids can simultaneously and asymmetrically be synthesized by a universal physical selection process.
A synergistic methodology will be developed to build a unified theory for the origin of all chiral biological building blocks and their assembly into homochiral supramolecular entities. For the first time, advanced analyses of astrophysical-relevant samples, asymmetric photochemistry triggered by circularly polarized synchrotron and laser sources, and chiral amplification due to polymerization processes will be combined. Intermediates and autocatalytic reaction kinetics will be monitored and supported by quantum calculations to understand the underlying processes. A unified theory on the asymmetric formation and self-assembly of life’s biopolymers is groundbreaking and will impact the whole conceptual foundation of the origin of life.
Ámbito científico
Programa(s)
Régimen de financiación
ERC-STG - Starting GrantInstitución de acogida
75794 Paris
Francia