The normal (B-form) DNA will switch to left-handed (Z-form) DNA when it is physically twisted, or when a lot of salt is added to the solution. DNA in the Z form is treated by our natural repair enzymes as damaged, and is therefore usually deleted from the cell. Deletion of genetic material can lead to cancer or to other problems, so the B-Z transition is no mere curiosity, says the researchers.
Researchers at the University of Luxembourg were able to accurately calculate for the first time the amount of salt which is required to predict this transition with unprecedented accuracy.
Dr. Josh Berryman and Professor Tanja Schilling of the University of Luxembourg are very optimistic that they will be able to perform similar mathematical analyses for a variety of other substances.
The paper entitled “Free Energies by Thermodynamic Integration Relative to an Exact Solution, Used to Find the Handedness-Switching Salt Concentration for DNA” was published in the Journal of Chemical Theory and Computation. (http://pubs.acs.org/doi/abs/10.1021/ct3005968 )