Amino acid enantiomers molecular interaction

Based on the stereoselectivity of immunoglobulins, a new chiral sensor for the detection of low-molecular-weight analytes was developed. Using surface plasmon resonance detection, enantiomers of free, underivatized a-amino acids can be monitored in a competitive assay by their interaction with antibodies specific for the chiral center of this class of substances. The sensitivity to the minor enantiomer in non-racemic mixtiues exceeds cunently available methods therefore, such immuuoseusors can readily detect traces of enantiomeric impurities and are attractive for a range of applications in science and industry. 

Recently, the association of amino acids and some other low-molecular weight compounds with rifamycin SV in water was studied by H NMR titrations. Rifamycin binds aromatic amino acids with pronounced enantioselectivity in favor of L-enantiomers and forms complexes with heterocyclic compounds but does not interact with aliphatic amino acids and with simple benzene derivatives. The binding constants for several guests are given in Figure 12. 

Spatial inversion has an important position in chemistry as the operation that connects two different enantiomers of a chiral molecule. Biochemically it is observed that for living organisms only L-amino acids are present in proteins, and that DNA and RNA are built up from D-sugars. In the wake of the discovery of P-odd processes, suggestions have been made that there may be a connection between this type of interaction and the natural selection of only one enantiomeric form for biochemical processes. It is possible to envision some interaction between molecular structure and the weak force that would favor one of the enantiomers energetically. 

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