title: Synthesis and monitored selection of nucleotide surrogates for binding T:A base pairs in homopurine-homopyrimidine DNA triple helices.
abstract: A total of 16 oligodeoxyribonucleotides of general sequence 5'-TCTTCTZTCTTTCT-3', where Z denotes an N-acyl-N-(2-hydroxyethyl)glycine residue, were prepared via solid phase synthesis. The ability of these oligonucleotides to form triplexes with the duplex 5'-AGAAGATAGAAAGA-HEG-TCTTTCTATCTTCT-3', where HEG is a hexaethylene glycol linker, was tested. In these triplexes, an 'interrupting' T:A base pair faces the Z residue in the third strand. Among the acyl moieties of Z tested, an anthraquinone carboxylic acid residue linked via a glycinyl group gave the most stable triplex, whose UV melting point was 8.4 degrees C higher than that of the triplex with 5'-TCTTCTGTCTTTCT-3' as the third strand. The results from exploratory nuclease selection experiments suggest that a combinatorial search for strands capable of recognizing mixed sequences by triple helix formation is feasible.
authors.affiliation: Department of Chemistry, University of Constance, Fach M 709, D-78457 Konstanz, Germany.
authors.forename: A A
authors.initials: AA
authors.lastname: Mokhir
authors.forename: W H
authors.initials: WH
authors.lastname: Connors
authors.forename: C
authors.initials: C
authors.lastname: Richert
mesh_terms: D020029:Base Pairing / Q000235:genetics; D001667:Binding, Competitive; D004247:DNA / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003851:Deoxyribonucleases / Q000378:metabolism; D007700:Kinetics; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000378:metabolism*; D011687:Purines / Q000378:metabolism*; D011743:Pyrimidines / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature
chemical_list: D009841:Oligonucleotides; D011687:Purines; D011743:Pyrimidines; C051802:triplex DNA; D004247:DNA; D003851:Deoxyribonucleases