(319b) Interaction Of C60 Derivatives And DNA Segments From Molecular Dynamics

We report atomistic modeling studies on the interaction of C60 derivatives and single stranded DNA segments in phosphate buffered solutions (PBS). Molecular dynamics simulation were performed for up to 15 ns to monitor the formation and stability of hybrids composed by C60 or its derivatives and single strand DNA segments. Compared with the results from our previous studies using dilute aqueous solution (Biophysical J., vol. 89, p3856, 2005), the association of C60 with ssDNA segments is not affected by the presence of concentrated salt ions in the system. In contrast, the binding pattern of C60 derivatives with ssDNA molecules depends on the size and shape of the functional groups. For C60 derivatives with a short hydrophilic group, the binding mechanism is still dominated by the hydrophobic force, with the binding pattern being similar to that for a native C60 and DNA segments. For C60 derivatives with a long hydrophilic functional group, the compound associates with the DNA segment by attaching part of its hydrophilic chain to the backbone of the DNA, resulting a hybrid with stronger binding energy. Our simulation results suggest that water soluble C60 derivatives can form stable complex with ssDNA in PBS solution. This may imply both adverse and appealing effects of C60 derivatives in biomedical applications.