Building up nanotubes: docking of "janus" cyclodextrins in solution

JAVIER RODRIGUEZ, ROCIO SEMINO Y DANIEL LARIA

JOURNAL OF PHYSICAL CHEMISTRY B

American Chemical Society

Lugar: Washington DC; Año: 2009 vol. 113 p. 1241 - 1244

1089-5647

Using molecular dynamics experiments, we analyze the association of ``Janus" 6-amino-6-deoxy-2$O$-carboxymethyl-$eta-$cyclodextrins (JCD) inaqueous solutions. In JCD dimers, the free energy associated with the upper-rim-lower-rim docking shows a stable minimum of $sim 60 $ kcal mol$^{-1}$. Trimers in solution are also remarkably stable over time spans of the order of tens of nanoseconds, exhibiting minimal distortions in their spatial and orientational distributions.The resulting geometrical docking shows the incipient characteristics of flexible nanotubes in solution,with eventual water interchange between the central channel and the bulk at the junctions between monomers.Structural and dynamical properties of the trapped water filling the nanotube are also examined.