title: Necessary conditions for the emergence of homochirality via autocatalytic self-replication.
abstract: We analyze a recent proposal for spontaneous mirror symmetry breaking based on the coupling of first-order enantioselective autocatalysis and direct production of the enantiomers that invokes a critical role for intrinsic reaction noise. For isolated systems, the racemic state is the unique stable outcome for both stochastic and deterministic dynamics when the system is in compliance with the constraints dictated by the thermodynamics of chemical reaction processes. In open systems, the racemic outcome also results for both stochastic and deterministic dynamics when driving the autocatalysis unidirectionally by external reagents. Nonracemic states can result in the latter only if the reverse reactions are strictly zero: these are kinetically controlled outcomes for small populations and volumes, and can be simulated by stochastic dynamics. However, the stability of the thermodynamic limit proves that the racemic outcome is the unique stable state for strictly irreversible externally driven autocatalysis. These findings contradict the suggestion that the inhibition requirement of the Frank autocatalytic model for the emergence of homochirality may be relaxed in a noise-induced mechanism.
authors.affiliation: Non-linearity and Complexity Research Group, System Analytics Research Institute, School of Engineering and Applied Science, Aston University, B4 7ET Birmingham, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Stich
authors.affiliation: Department of Organic Chemistry, Institute of Cosmos Science (IEEC-UB), University of Barcelona, Barcelona, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Ribó
authors.affiliation: Department of Chemistry, The Scripps Research Institute, La Jolla, California 93207, USA.
authors.forename: Donna G
authors.initials: DG
authors.lastname: Blackmond
authors.affiliation: Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Carretera Ajalvir Kilómetro 4, 28850 Torrejón de Ardoz, Madrid, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Hochberg
mesh_terms: D002384:Catalysis; D013237:Stereoisomerism; D013816:Thermodynamics