Prebiotic Peptides Based on the Glycocodon Theory Analyzed with FRET.

In modern protein-carbohydrate interactions, carbohydrate-aromatic contact with CH-π interactions are used. Currently, they are considered driving forces of this complexation. In these contacts, tryptophan, tyrosine, and histidine are preferred. In this study, we focus on primary prebiotic chemistry when only glycine, alanine, aspartic acid, and valine are available in polypeptides. In this situation, when the aromatic acids are not available, hydrogen-bonding aspartic acid must be used for monosaccharide complexation. It is shown here that (DAA)n polypeptides play important roles in primary "protein"-glucose recognition, that (DGG)n plays an important role in "protein"-ribose recognition, and that (DGA)n plays an important role in "protein"-galactose recognition. Glucose oxidase from Aspergillus niger, which still has some ancient prebiotic sequences, is chosen here as an example for discussion.