Weak neutral current and β radiolysis effects on the origin of biomolecular chirality

The possibility of a connection between the parity non-conserving weak interactions and the handedness of biomolecules has received recent attention1. Although the asymmetric effects of the weak interactions in molecules have been estimated to be very small2–9, Kondepudi and Nelson (KN)10–13 have shown that autocatalytic chemical systems that spontaneously break chiral symmetry14–19 can effectively amplify systematic chiral perturbations as small as those produced by weak neutral currents2–4,20, despite the simultaneous presence of larger randomly fluctuating chiral perturbations, and hence provide a mechanism for producing the observed homochirality of biomolecules. I show here, in the light of new estimates of the asymmetric decomposition of racemic mixtures by β radiation9, that the chiral selection parameter due to β radiolysis can be up to six orders of magnitude larger than that resulting from weak neutral currents. This suggests that β radiolysis is more likely to be the selector of biomolecular chirality than weak neutral currents.