Spontaneous mirror symmetry breaking in the limited enantioselective autocatalysis model: abyssal hydrothermal vents as scenario for the emergence of chirality in prebiotic chemistry

Astrobiology. 2013 Feb;13(2):132-42. doi: 10.1089/ast.2012.0904. Epub 2013 Feb 4.

Abstract

The emergence of chirality in enantioselective autocatalysis for compounds unable to transform according to the Frank-like reaction network is discussed with respect to the controversial limited enantioselectivity (LES) model composed of coupled enantioselective and non-enantioselective autocatalyses. The LES model cannot lead to spontaneous mirror symmetry breaking (SMSB) either in closed systems with a homogeneous temperature distribution or in closed systems with a stationary non-uniform temperature distribution. However, simulations of chemical kinetics in a two-compartment model demonstrate that SMSB may occur if both autocatalytic reactions are spatially separated at different temperatures in different compartments but coupled under the action of a continuous internal flow. In such conditions, the system can evolve, for certain reaction and system parameters, toward a chiral stationary state; that is, the system is able to reach a bifurcation point leading to SMSB. Numerical simulations in which reasonable chemical parameters have been used suggest that an adequate scenario for such a SMSB would be that of abyssal hydrothermal vents, by virtue of the typical temperature gradients found there and the role of inorganic solids mediating chemical reactions in an enzyme-like role.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Chemistry, Physical
  • Exobiology
  • Hydrothermal Vents / chemistry*
  • Models, Chemical*
  • Stereoisomerism
  • Thermodynamics