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. 1988 Jan 25;16(2):719–738. doi: 10.1093/nar/16.2.719

CD of six different conformational rearrangements of poly[d(A-G).d(C-T)] induced by low pH.

V P Antao 1, D M Gray 1, R L Ratliff 1
PMCID: PMC334687  PMID: 3340552

Abstract

On the basis of circular dichroism (CD) data, we have now identified six different conformational states (other than the duplex) of poly[d(A-G).d(C-T)] at pH values between 8 and 2.5 (at 0.01M Na+; 20 degrees C). Three of these structural rearrangements were observed as the pH was lowered from 8 to 2.5, and three additional rearrangements were observed as the pH was raised from 2.5 back to neutral pH. The major components of the six conformational states were defined using appropriate combinations of the CD spectra of the duplex, triplex, and denatured forms of this polymer, as well as the CD spectra of the individual single strands and their respective acid-induced self-complexes. Our results show that the acid-induced rearrangements of poly[d(A-G).d(C-T)] include not only the poly[d(C+-T).d(A-G).d(C-T)] triplex, but also include the poly[d(C-T)] loop-out structure and a self-complexed form of the poly[d(A-G)] strand that is pH-dependent.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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