Selective adsorption of l - and d -amino acids on calcite: Implications for biochemical homochirality

作者：Robert M. Hazen, T. R. Filley, Glenn A. Goodfriend · 发表于：Proceedings of the National Academy of Sciences · 年份：2001 · DOI：10.1073/pnas.101085998 · 被引用次数：397 · 研究领域：Origins and Evolution of Life、Enzyme Structure and Function、Amino Acid Enzymes and Metabolism

The emergence of biochemical homochirality was a key step in the origin of life, yet prebiotic mechanisms for chiral separation are not well constrained. Here we demonstrate a geochemically plausible scenario for chiral separation of amino acids by adsorption on mineral surfaces. Crystals of the common rock-forming mineral calcite (CaCO(3)), when immersed in a racemic aspartic acid solution, display significant adsorption and chiral selectivity of d- and l-enantiomers on pairs of mirror-related crystal-growth surfaces. This selective adsorption is greater on crystals with terraced surface textures, which indicates that d- and l-aspartic acid concentrate along step-like linear growth features. Thus, selective adsorption of linear arrays of d- and l-amino acids on calcite, with subsequent condensation polymerization, represents a plausible geochemical mechanism for the production of homochiral polypeptides on the prebiotic Earth.