Modelling of beta-cyclodextrin with L-alpha-aminoacids residues

A computational study of host-guest inclusion complexes between beta-cyclod extrin (beta-CD) and the 20 natural L-alpha-aminoacids and some selected pe ntapeptides was carried out and aimed at understanding the nature of the dr iving forces and mechanism leading to their formation. Relative complexatio n energies for the complexes with beta-CD were calculated in both cases and the solvation Gibbs free energies were also evaluated for the single L-alp ha-aminoacids. The computed results indicate strong possibilities of format ion of inclusion complexes between beta-CD and single L-alpha-aminoacids as well as pentapeptides which have hydrophobic side chains. In addition, not eworthy interactions of the side chain of the pentapeptides with the beta-C D were also elucidated. A detailed molecular dynamics calculation of one of the representative pentapeptide/beta-CD inclusion complex (beta-CD/CH3-Ala -Ala-TYR-Ala-Ala-CH3) in aqueous solution has also been carried out. Molecu lar dynamics calculations support aspects connected with the formation and description of hydrogen bonds and with the role of dispersion forces in the inclusion complex in water.