Unique properties of purine/pyrimidine asymmetric PNA.DNA duplexes: differential stabilization of PNA.DNA duplexes by purines in the PNA strand.

ABSTRACT: PNA.DNA duplexes are significantly stabilized by purine nucleobases in the PNA strand. To elucidate and understand the effect of switching the backbone in a nucleic acid duplex, we now report a thermodynamics study along with a solution conformations study of two purine/pyrimidine strand asymmetric duplexes and a strand symmetrical control by comparing the behavior of all four possible PNA/DNA combinations. In essence, we are comparing an identical basepair stack connected by either an aminoethyl glycine PNA or a deoxyribose DNA backbone. We show that the PNA.DNA duplexes containing purine-rich PNA strands are stabilized with regard to the thermal melting temperature and free energy as well as enthalpy (and concomitantly relatively less entropically disfavored). Based on our data, we find

SUBMITTER: Sen A 

PROVIDER: S-EPMC1367284 | biostudies-literature | 2006 Feb

REPOSITORIES: biostudies-literature