Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

PNA-DNA Stability

  1. Oct 2, 2009 #1
    If "unzipped" PNA and DNA combine to form a double helix, will the hybrid be more or less stable than a pure DNA double helix? This was a question on my chem homework (in a section on intermolecular forces), but I'm posting in this section as I already turned in the homework so I'm asking more out of curiosity than anything. The only real information I had on PNA was that its backbone is neutral, while I know that the phosphates in DNA give its backbone a negative (-2?) charge. I'm not sure how these really affect each other, as the base pairs are what connect the two together, but the charges seemed to be emphasized in the question, and this really confused me.

    I'm not sure how common PNA (peptide nucleic acid) is, but I asked this question to some grad students in the bio lab where I work, and they weren't too sure as they hadn't worked much with PNA (a few didn't remember even learning about it actually). On my homework I guessed that it would be less stable, just because I know that DNA is pretty stable as it is, but I'm starting to think the stabilities would be about equal, and that the part about the charges was just thrown to distract me. Anyway, if anyone can even help me out with the thought process in this problem, I'd appreciate it.
  2. jcsd
  3. Oct 2, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    I would say that the bonding should be stronger in PNA since all things being equal, a neutral backbone would lack charge repulsion present in both DNA and RNA. The interstrand bonding is identical to that of DNA... identical purine and pyrimidine bases are present in both classes of compounds and both form the same Watson-Crick pairs .
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Stability Date
Question about stability of Ozone Nov 20, 2017
Energy gap between orbitals and stability Jun 8, 2017
Resonance and Stability Jan 30, 2017
Stability of solutions Sep 30, 2016
Stability of aromatic compounds Jul 27, 2016