Vacuum UV CD spectra of homopolymer duplexes and triplexes containing A.T or A.U base pairs.
AUTOR(ES)
Johnson, K H
RESUMO
Vacuum UV circular dichroism (CD) spectra were measured down to 174 nm for five homopolymers, five duplexes, and four triplexes containing adenine, uracil, and thymine. Near 190 nm, the CD bands of poly[d(A)] and poly[r(A)] were larger than the CD bands of the polypyrimidines, poly[d(T)], poly[d(U)], and poly[r(U)]. Little change was observed in the 190 nm region upon formation of the duplexes (poly[d(A).d(T)], poly[d(A).d(U)], poly[r(A).d(T)], poly[r(A).d(U)], and poly[r(A).r(U)]) or upon formation of two of the triplexes (poly[d(T).d(A).d(T)] and poly[d(U).d(A).d(U)]). This showed that the purine strand had the same or a similar structure in these duplexes and triplexes as when free in solution. Both A.U and A.T base pairing induced positive bands at 177 and 202 nm. For three triplexes containing poly[d(A)], the formation of a triplex from a duplex and a free pyrimidine strand induced a negative band centered between 210 and 215 nm. The induction of a band between 210 and 215 nm indicated that these triplexes had aspects of the A conformation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=329430Documentos Relacionados
- CD of homopolymer DNA-RNA hybrid duplexes and triplexes containing A-T or A-U base pairs.
- A new model for DNA containing A.T and I.C base pairs.
- The vacuum UV CD spectra of G.G.C triplexes.
- Tracts of A.T base pairs retard the electrophoretic mobility of short DNA duplexes.
- Characterization of imperfect DNA duplexes containing unpaired bases and non-Watson-Crick base pairs.