The crystal-packing and cohesive energies in the structures of two polymorphs of the title tetrapeptide have been analyzed using molecule-molecule energies calculated using the PIXEL method. Coulombic energies are non-empirical and are much more accurate than those calculated using point-charge methods. The results explain and rationalize the cohesion and mutual recognition of these peptide molecules, with a clear distinction between polar and dispersive contributions, shedding light on subtle differences between polymorphic arrangements. For systems of the present size, the necessary calculations can be carried out on a personal computer and require quite acceptable computing times. Although an extension to larger peptides is problematic for obvious reasons, it is suggested that this type of analysis could be a valuable and practical tool in the understanding of the principles of peptide aggregation.
|Titolo:||Coulombic and dispersive factors in the molecular recognition of peptides: PIXEL calculations on two NNQQ (Asn-Asn-Gln-Gln) crystal polymorphs|
GAVEZZOTTI, ANGELO (Primo)
|Parole Chiave:||Intermolecular energies; NNQQ crystal polymorphs; Peptide aggregation; PIXEL|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
|Data di pubblicazione:||2008|
|Digital Object Identifier (DOI):||10.1107/S0907444908018568|
|Appare nelle tipologie:||01 - Articolo su periodico|