Abstract
The effect of DNA base composition on the kinetics of the association between DNA and proflavine has been investigated using the temperature jump relaxation method. It is found that, regardless of the G + C base composition the results fit a two step mechanism, the second of which exhibits characteristics of intercalation of proflavine into DNA. However, the two Co equilibrium constants corresponding to these steps, K I and K II, depend on the nature of the DNAs. The constant K I is found to be an order of magnitude ureater for M. lysodcikricus DNA (72% G + C) than for calf thymus DNA (48% G + C). Increasing G-C content thus appears to favor the intermediate non-intercalated complex of proflavine with DNA. Methylation of M. lysudeiktiws DNA with dimethyl sulfate, preferentially yielding N 7 methyl guanine as the modified base, again leads to an apparent two step mechanism, with the value of K I unchanged with respect to untreated DNA, while the affinity of proflavine for the intercalated complet measured by the value of K II increases for methylated DNA.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
