Page - 107 - in Charge Transport in DNA - Insights from Simulations

In the next part, the charge transport and charge transfer inmicrohydratedDNA strandswas investigated. Itwasshownthat theefficiencyof charge transfer/trans- port inmicrohydratedDNA is similar to that inDNA in bulk solution, provided the regulardouble-strandedstructure ispreserved. Themagnitudeaswell asfluc- tuations of the electric field induced by the aqueous environment are due to the closest hydration shells. The importantCTquantities showedrathermoderatedif- ferences between the fully hydrated and themicrohydrated systems. Therefore, it seems conceivable that the transport of electric charge in amicrosolvated complex molecular systemwill exhibit similar characteristics as that in the same system in bulk solution, as longas the structureof the closest solvation shell is retained. In the final part of thiswork, a newlydevelopedparametrizedmodel to simulate theCT inDNAwas introduced. The relevantparameters for theCTwerefitted to results fromQM/MMsimulations. Testingwas performedon awell-investigated DNAoligomer. Crucial behaviors and statistics are reproduced quantitatively by the CT model. Therefore, charge transportandcharge transfercalculationscanbeperformedwith themodel. The computational efficiency of themodel is about 3orders ofmagni- tude higher than that of the QM/MM approach. In conclusion, this CT model makes investigation of very longDNAsequences (up to thousands of base-pairs) over extensiveperiodsof timepossible. 107 Conclusion