Q3 Please search references for these questions Compare the hybridization streng

Question

Q3 Please search references for these questions

Compare the hybridization strengths for the PNA-DNA (or RNA) complex and DNA-DNA (RNA) complex in the same condition. ______________.

Salt concentration is an important factor to regulate hybridization strength:

How does PNA-DNA binding strength change with salt concentration? ____. Why?_____________________

How does DNA-DNA binding strength change with salt concentration? ____. Why?_____________________

Provide references here, if you have_______________________

Explanation / Answer

Antiparallel PNA-DNA duplex formation is very fast, faster than formation of a corresponding DNA-DNA duplex, whereas considerably slower kinetics were observed for formation of parallel PNA-DNA complexes . The thermal stability of PNA-RNA duplexes is generally higher than that of PNA-DNA duplexes, and the rate of association between PNA and RNA is somewhat faster than that between PNA and DNA.

The stability of PNA-DNA hybrids is little affected by changes in ionic strength, except in the limit of low ionic strength, where the stability increases. The higher stability of PNA-DNA compared with DNA-DNA duplexes at low ionic strength is due to a more favorable entropy change linked to duplex formation, which is attributed to a release of counterions from the DNA polyanion as PNA binds (5).

PNA-DNA and DNA-DNA duplexes have equal thermal stability (melting temperatures) at ionic strengths above 1 M Na+.

Reference: http://what-when-how.com/molecular-biology/peptide-nucleic-acids-part-1-molecular-biology/

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