These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Polycyclic azoniahetarenes: assessing the binding parameters of complexes between unsubstituted ligands and G-quadruplex DNA.
    Author: Jäger K, Bats JW, Ihmels H, Granzhan A, Uebach S, Patrick BO.
    Journal: Chemistry; 2012 Aug 27; 18(35):10903-15. PubMed ID: 22807262.
    Abstract:
    Polycyclic azoniahetarenes were employed to determine the effect of the structure of unsubstituted polyaromatic ligands on their quadruplex-DNA binding properties. The interactions of three isomeric diazoniadibenzo[b,k]chrysenes (4 a-c), diazoniapentaphene (5), diazoniaanthra[1,2-a]anthracene (6), and tetraazoniapentapheno[6,7-h]pentaphene (3) with quadruplex DNA were examined by DNA melting studies (FRET melting) and fluorimetric titrations. In general, penta- and hexacyclic azoniahetarenes bind to quadruplex DNA (K(b) ≈10(6) M(-1)) even in the absence of additional functional side chains. The binding modes of 4 a-c and 3 were studied in more detail by ligand displacement experiments, isothermal titration calorimetry, and CD and NMR spectroscopy. All experimental data indicate that terminal π stacking of the diazoniachrysenes to the quadruplex is the major binding mode; however, because of different electron distributions of the π systems of each isomer, these ligands align differently in the binding site to achieve ideal binding interactions. It is proposed that tetraazonia ligand 3 binds to the quadruplex by terminal stacking with a small portion of its π system, whereas a significant part of the bulky ligand most likely points outside the quadruplex structure, and is thus partially placed in the grooves. Notably, 3 and the known tetracationic porphyrin TMPyP4 exhibit almost the same binding properties towards quadruplex DNA, with 3 being more selective for quadruplex than for duplex DNA. Overall, studies on azonia-type hetarenes enable understanding of some parameters that govern the quadruplex-binding properties of parent ligand systems. Since unsubstituted ligands were employed in this study, complementary and cooperative effects of additional substituents, which may interfere with the ligand properties, were eliminated.
    [Abstract] [Full Text] [Related] [New Search]