ISSN:
1572-8927
Schlagwort(e):
DNA duplex
;
hairpin
;
human enkaphalin gene
;
differential scanning calorimetry
;
enthalpy of melting
;
cooperative units
;
pH dependence
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract Two complementary 23 base-pair oligomers with sequences analogous to the 3′, 5′-cyclic adenosine monophosphate (cAMP) inducible enhancer region of the human enkaphalin gene were shown previously(6) to undergo reversible conformational transformation from duplex to two individual hairpin structures, with two GT and two AC base mismatches, respectively. The present study uses differential scanning calorimetry (DSC) to determine ΔH values for both the dissociation of the duplex formed by the complementary stands and the melting of each hairpin structure. Melting of the hairpins was studied at several different pH values and both the ΔH and cooperative unit (CU) parameters for the hairpin with the AC base mismatches was found to be pH dependent. Increased values for ΔH of melting and cooperative unit size at lower pH values supports the possibility of protonation of adenosine bases and formation of stable AC base pairs in this latter hairpin.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1021724229634
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