Chiral Interactions of Histidine in a Hydrated Vermiculite

• Main Authors: Fraser, Donald G, Greenwell, H. Christopher, Skipper, Neal T, Smalley, Martin V, Wilkinson, Michael A, Demé, Bruno, Heenan, R. K
• Format: Journal Article
• Language: English
• Published: 14-07-2010
• Subjects: Physics - Biological Physics; Physics - Soft Condensed Matter; Quantitative Biology - Biomolecules
• DOI: 10.48550/arxiv.1007.2432

Recent work suggests a link between chiral asymmetry in the amino acid
iso-valine extracted from the Murchison meteorite and the extent of hydrous
alteration. We present the results of neutron scattering experiments on an
exchanged, 1-dimensionally ordered n-propyl ammonium vermiculite clay. The
vermiculite gel has a (001) d-spacing of order 5nm at the temperature and
concentration of the experiments and the d-spacing responds sensitively to
changes in concentration, temperature and electronic environment. The data show
that isothermal addition of D-histidine or L-histidine solutions produces
shifts in the d-spacing that are different for each enantiomer. This chiral
specificity is of interest for the question of whether clays could have played
an important role in the origin of biohomochirality.