Carboxyl-carboxyl(ate) motifs classification and biomolecular implications
What is it about?
The carboxylic acid group (and carboxylate conjugated base) is ubiquitous in chemistry where carboxyl-carboxyl(ate) motifs act as important building blocks (synthons), and in biology. We reduced the vast diversity of carboxyl-carboxyl(ate) interaction modes to seventeen motifs by surveying crystallographic structures from the CSD. A systematic nomenclature for these and related polymeric-like catemers is provided along with considerations on their hydrogen bonding patterns.
Why is it important?
This analysis of small molecular (high-resolution) structures should have implications for crystal engineering and pharmaceutical research (in particular drug co-crystallization). It should also provide new insights into the properties and behavior of the more complex biomolecular systems containing hydrogen bonded pairs of Asp and Glu residues or neutral Asp/Glu amino acids bound to nucleic acids.