Thermodynamic studies of base pairing involving 2,6-diaminopurine.
The thermal stabilities of oligodeoxyribonucleotide duplexes containing 2,6-diaminopurine (D) matched with each of the four normal DNA bases were determined by optical melting techniques. Comparison of optical melting curves yielded relative stabilities for the D-containing standard base pairs in an otherwise identical base-pair sequence. The D:T pair was found to be more stable than the A:T pair in dC3DG3:dC3TG3, as stable as the A:T in dCT3DT3G:dCA3TA3G, and less stable than the A:T in dCA3DA3G:dCT7G. The order of stabilities for X:Y in the DNA duplex dCA3XA3G:dCT3YT3G is: (A:T) greater than (T:D) congruent to (D:T) greater than or equal to (T:A) greater than (C:D) congruent to (D:A) congruent to (D:G) greater than or equal to (D:C) congruent to (G:D) congruent to (D:D) greater than or equal to (A:D). Implications of these results for design of DNA oligonucleotide probes are discussed.
Cheong
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Department of Chemistry, University of California, Berkeley 94720.
Tinoco
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I
Chollet
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D015075:2-Aminopurine / Q000031:analogs & derivatives* / Q000378:metabolism; D000225:Adenine / Q000031:analogs & derivatives*; D001482:Base Composition; D009838:Oligodeoxyribonucleotides / Q000378:metabolism; D013816:Thermodynamics
D009838:Oligodeoxyribonucleotides; D015075:2-Aminopurine; C007300:2,6-diaminopurine; D000225:Adenine