A long-standing puzzle in biology is the predominance of left-handed amino acids over right-handed ones – a huge violation of parity, which physicists have tried at various times to link to the parity violation well known in the weak interaction. This has often involved invoking sensitive processes far from equilibrium to amplify the incredibly tiny (but nonzero) difference in energies between left- and right-handed amino acids.
Martin Klussmann of Imperial College London and colleagues have now brought us closer to understanding how this imbalance may have occurred. They found that even in equilibrium, there are reactions catalysed by amino acids that involve some tricky thermodynamics of both solid and dissolved amino acids, and these can result in enormous asymmetries of one handedness of amino acid over the other. As well as helping to understand a basic fact of biology, the work could lead to improved synthesis of medically important molecules, many of which have different properties depending on their handedness.
Further reading
Martin Klussmann et al. 2006 Nature 441 621.