2-Aminopurine-Modified Abasic-Site-Containing Duplex DNA for Highly Selective Detection of Theophylline

Abstract

2-Aminopurine-modified abasic-site-containing duplex [DNA 5'-TCTGC GTCCT PXT TAACG CACAC-3'/3'-AGACG CAGGA TCA ATTGC GTGTG-5'; P = 2-aminopurine, X = abasic site (Spacer-C3), C = receptor base] is capable of selectively binding to the bronchodilator theophylline with a dissociation constant of 10 microM (5 degrees C, pH 7.0, I = 0.11 M) and is applicable to monitoring serum theophylline concentrations.

DNA Triplexes That Bind Several Cofactor Molecules

“…Thisd esign gives ah igh theoretical storaged ensity and requires less synthetic effort than composite linkers. At otal of seven different www.chemeurj.org motifs were studied (11)(12)(13)(14)(15)(16)(17), ranging from 11 that lacks ap urine toehold between the h-bridged binding regionsa nd 16 and 17 with five residues in the centralp urine segment between the two bridged binding sites ( Figure 6). Compound 17 containsastilbened iether bridge [41][42] between the two Watson-Crick pairing segments.…”

“…But, as long as the number of single nucleotide binding sites is reasonable, high affinity for each of Figure 6. Apparentdissociation constants( K dapparent )for the complexes of FADa nd intramolecular tripleh elicalbinding motifs differing in the length of the inner purine segment (toehold) between two hexaethyleneg lycol-bridged binding sites (11)(12)(13)(14)(15)(16), as well as amotif with ad uplex-stabilizing stilbene diether bridge (17). Conditions:5mM bindingm otif,30mMF AD in phosphate buffer (10 mM,pH= 6), 1 M NaCl; centrifugation at 4 8Ct hrough filter units with am olecularw eight cut-off of 3kDa.…”

A novel electrochemical method to detect theophylline utilizing silver ions captured within abasic site-incorporated duplex DNA

“…1. The AP site within duplex DNA immobilized on the surface of electrode serves as a binding pocket for theophylline through pseudo base pairing with the opposite cytosine that is stabilized by nucleobases adjacent to the AP site (Li et al, 2009;Pang et al, 2012). At the same time, the cytosine nucleobase positioned opposite the AP site also captures silver ions through its strong interaction (Ma et al, 2011;Park and Park, 2014) when the AP site is not occupied by target theophylline (Fig.…”

“…Theophylline bound into the AP site changes the microenvironment of fluorescent 2-aminopurine, which consequently results in the significant reduction of fluorescence signal from 2-aminopurin (Pang et al, 2012). Although interesting, the need for the modification of DNA probe with 2-aminupurine might make the assay a little complicated and expensive (Li et al, 2009).…”

Molecular recognition patterns of 2-aminopurine versus adenine: A view through ternary copper(II) complexes

“…Its red-shifted absorption, relative to that of typical nucleic acids and proteins, as well as the extreme sensibility of fluorescence to local environmental factors, has enhanced the use of 2-aminopurine as molecular probe to investigate problems in structural biology, biochemistry and biophysics. It should be highlighted the researches on reaction mechanisms of different RNA and DNA enzymes [13], probing of conformational transitions and dynamics of nucleic acids [14] and studies about the interactions between nucleic acids and proteins or small molecules [15,16].…”