Yet another possible explanation for the bias in life’s handedness – the fact that nature uses mainly only form of the building blocks of proteins – comes from Dutch chemists experimenting with the sublimation of amino acids.
Writing in the latest issue of my alma mater Chemical Communications, Ben Feringa and colleagues at the University of Groningen have demonstrated significant enantioenrichment of a variety of amino acids by sublimation in which preferential evaporation of the predominant enantiomer occurs from a mixture of low ee amino acids. They lay claim to this process as being a possible mechanism for the presence of ee of amino acids under the conditions found in space.
Theories abound as to why life on earth predominantly uses L amino acids. Most rely on some obscure initial set conditions and a convoluted route from a small excess in outer space to the seeding of amino acids on earth. While Feringa and colleagues discuss their findings in terms of interplanetary conditions it may be just as possible that their process had some counterpart on the primordial earth.