Spontaneous Mirror Symmetry Breaking in the Limited Enantioselective Autocatalysis Model: Abyssal Hydrothermal Vents as Scenario for the Emergence of Chirality in Prebiotic Chemistry

TL;DR

This paper demonstrates that spontaneous mirror symmetry breaking in prebiotic chemistry can occur in a two-compartment model with temperature gradients, suggesting hydrothermal vents as a plausible environment for the emergence of biological chirality.

Contribution

It introduces a two-compartment kinetic model showing SMSB under temperature gradients, expanding understanding of chiral symmetry breaking in prebiotic conditions.

Findings

SMSB occurs with spatially separated autocatalytic reactions at different temperatures.

Hydrothermal vents provide a plausible environment for SMSB due to temperature gradients.

The model predicts chiral stationary states under certain parameters.

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 nor 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 continous internal flow. In such conditions the system can evolve, for certain reaction and system parameters, towards a chiral stationary state, i.e., the system is able to reach a bifurcation point leading to SMSB. Numerical simulations using reasonable chemical parameters 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.