title: Mechanically Induced Homochirality in Nucleated Enantioselective Polymerization.
abstract: Understanding how biological homochirality may have emerged during chemical evolution remains a challenge for origin of life research. In keeping with this goal, we introduce and solve numerically a kinetic rate equation model of nucleated cooperative enantioselective polymerization in closed systems. The microreversible scheme includes (i) solution-phase racemization of the monomers, (ii) linear chain growth by stepwise monomer attachment, in both nucleation and elongation phases, and (iii) annealing or fusion of homochiral chains. Mechanically induced breakage of the longest chains maintains the system out of equilibrium and drives a breakage-fusion recycling mechanism. Spontaneous mirror symmetry breaking can be achieved starting from small initial enantiomeric excesses due to the intrinsic statistical fluctuations about the idealized racemic composition. The subsequent chiral amplification confirms the model's capacity for absolute asymmetric synthesis, without chiral cross-inhibition and without explicit autocatalysis.
authors.affiliation: Department of Chemistry and Biochemistry, University of California , Santa Barbara, California 93106-9510, United States.
authors.forename: Celia
authors.initials: C
authors.lastname: Blanco
authors.affiliation: Non-Linearity and Complexity Research Group, System Analytics Research Institute, School of Engineering and Applied Science, Aston University , B4 7ET Birmingham, U.K.
authors.forename: Michael
authors.initials: M
authors.lastname: Stich
authors.affiliation: Department of Molecular Evolution, Centro de Astrobiologı́a (CSIC-INTA) , Carretera Ajalvir Kilómetro 4, Torrejón de Ardoz 28850 Madrid, Spain.
authors.forename: David
authors.identifier: 0000-0002-0411-019X
authors.initials: D
authors.lastname: Hochberg
mesh_terms: D019418:Evolution, Chemical; D058105:Polymerization; D013237:Stereoisomerism; D013816:Thermodynamics; D013997:Time Factors