The energetic basis of the DNA double helix: a combined microcalorimetric approach.

ABSTRACT: Microcalorimetric studies of DNA duplexes and their component single strands showed that association enthalpies of unfolded complementary strands into completely folded duplexes increase linearly with temperature and do not depend on salt concentration, i.e. duplex formation results in a constant heat capacity decrement, identical for CG and AT pairs. Although duplex thermostability increases with CG content, the enthalpic and entropic contributions of an AT pair to duplex formation exceed that of a CG pair when compared at the same temperature. The reduced contribution of AT pairs to duplex stabilization comes not from their lower enthalpy, as previously supposed, but from their larger entropy contribution. This larger enthalpy and particularly the greater entropy results from water fixed

SUBMITTER: Vaitiekunas P 

PROVIDER: S-EPMC4787831 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature