Poly(8-aminoguanylic acid): formation of ordered self-structures and interaction with poly(cytidylic acid)

M HattoriH T Miles


Poly(8-aminoguanylic acid) has in neutral solution a novel ordered structure of high stability. The 8-amino group permits formation of three hydrogen bonds between two residues along the "top", or long axis, of the purines. The usual hydrogen bonding protons and Watson-Crick pairing sites are not involved in the association. The bonding scheme has a twofold rotation axis and is hemiprotonated at N(7). Poly(8NH2G) is converted by alkaline titration (pK = 9.7) to a quite different ordered structure, which is the favored form over the range approximately pH 10-11. The bonding scheme appears to be composed of a planar, tetrameric array of guanine residues, in which the 8-amino group does not participate in interbase hydrogen bonding. Poly (8NH2G) does not interact with poly(C) in neutral solution because of the high stability of the hemiprotonated G-G self-structure. Titration to the alkaline plateau, however, permits ready formation of a two-stranded Watson-Crick helix. In contrast to the monomer 8NH2GMP, poly(8NH2G) does not form a triple helix with poly(C) under any conditions. The properties of the ordered structures are interpreted in terms of a strong tendency of the 8-amino group to form a third interbase hydrogen bond, when...Continue Reading


Apr 1, 1977·Biopolymers·F B HowardH T Miles
Jan 5, 1999·Bioorganic & Medicinal Chemistry Letters·R Güimil GarcíaM Orozco
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Dec 1, 1990·Journal of Biomolecular Structure & Dynamics·W GuschlbauerD Thiele
Nov 10, 2000·Nucleic Acids Research·R SolivaM Orozco
Mar 27, 2009·Chemical Communications : Chem Comm·Aaron E EngelhartNicholas V Hud
Aug 24, 1976·Biochemistry·F B HowardH T Miles
Nov 26, 2019·The Journal of Craniofacial Surgery·Karel-Bart CelieThomas Imahiyerobo
May 26, 2017·Chemical Communications : Chem Comm·Taylor N PlankJeffery T Davis

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