Stability base pairs

Damha, M.J., Giannaris, P.A., and Marfey, P., Antisense L/D-oligodeoxynucleotide chimeras nuclease stability, base-pairing properties, and activity at directing ribonuclease H, Biochemistry, 33, 7877,1994. 

Section 28 8 The most common form of DNA is B DNA which exists as a right handed double helix The carbohydrate-phosphate backbone lies on the outside the punne and pyrimidine bases on the inside The double helix IS stabilized by complementary hydrogen bonding (base pairing) between adenine (A) and thymine (T) and guanine (G) and cytosine (C)... 

Chromatin is composed of nucleosomes, where each comprise 147 base pairs of DNA wrapped around an octamer oftwo copies of each histone H2A, H2B, H3, and H4. Nucleosomes are folded into higher-order structures that are stabilized by linker histones. Chromatin structure can be altered by enzymes that posttranslationally modify histones (e.g., through phosphorylation, acetylation, methylation, or ubiquitination) or by ATP-driven chromatin-remodeling complexes that alter nucleosome position and/or composition. 

A buffer is a mixture of a weak conjugate acid-base pair that stabilizes the pH... 

Since our original aPNA publication, there have been other reports of the incorporation of nucleobases into a-helical peptides. Mihara and coworkers reported that a-hehcal coiled-coiled peptides could be stabilized by base pairs between complementary y-nucleobase-a-aminobutanoic acids [78] They have also reported that the incorporation of such nucleoamino acids into a-hehcal segments of HIV-1 Rev and HIV-1 nucleocapsid protein can result in increased binding affinity and specificity to HIV-1 RRE RNA and SL3 RNA respectively [79, 80]. 

Several base pairs of adenine-thymine, including the WC pair, have also been studied [238], It is found that a charge transfer state exists about 1.5 eV higher than the local nn states. Proton transfer between the bases stabilizes a charge transfer state which then crosses with the ground state facilitating radiationless relaxation. This mechanism is not energetically favorable for non WC pairs. 

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