Abstract
A combination of spectroscopic and calorimetric techniques has been used to characterize the structures formed by a family of short, guanine-containing DNA single strands of the form d[GGTTXTTGG], X = A, C, G, T. In 1 molar NaCl at low temperatures, these molecules do not behave like single strands, but rather exhibit properties consistent with tetraplex formation. The standard state enthalpies, entropies, and free energies for formation of each tetraplex have been measured, as have preliminary nuclear magnetic resonance (NMR) spectra. In 1 molar KCl, the melting behavior of the structure or structures is more complex than in 1 molar NaCl. This observation may be related to the recently proposed "sodium-potassium switch."
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have