Improvement of porphyrins for G-quadruplex DNA targeting

Keeping those telomeres short! an innovative intratumoral long-term drug delivery system

“…It has been reported that, with TMPyP4, the presence of a cation, such as K + , can preferentially induce the conformational conversion of the GQ from the parallel type to the parallel/antiparallel mixture (Zhang et al 2009). Conversely, while attempting to improve GQ binding, charge was introduced into the centre of TMPyP4 but was shown to have little influence on binding (Romera et al 2011). The formation of GQs in DNA and the influence of metal complexes are gaining increasing attention within the scientific community (Georgiades 2010;Hatzakis et al 2010).…”

Porphyrins in complex with DNA: Modes of interaction and oxidation reactions

“…Bulky porphyrin derivatives H 2 -TMPipEOPP, H 2 -TMPy2PP, H 2 -GP, H 2 -DIGPor and H 2 -TPyEtCAP can perfectly discriminate between quadruplex and double-stranded DNA [63,69,71,[116][117][118][119][120]. Their binding constants for quadruplex DNA is comparable to that of best G4 ligands [120].…”

“…The variations in the binding constant arise from different quadruplex DNA, ionic strengths and experimental conditions. However, as mentioned above, the high affinity of H 2 -TMPyP4 for DNA makes it not selective for G4 DNA [44,71].…”

“…The strongest one is minor groove binding with Ka values in the order of 10 6 -10 7 M -1 [37,43,68,70], intercalation leads to Ka values around 10 6 M -1 [34,37,43] and finally, non-specific electrostatic interactions account for Ka values of about 10 4 -10 5 M -1 [71].…”

Efficient DNA Cleavage Induced by RhIII(TMPyP)5+ in the Presence of Ascorbic Acid

“…Porphyrins and metalloporphyrins have been studied extensively by various research groups because of their uses in photodynamic therapy, cancer detection and virus inhibition (McMillin et al, 2005;Romera et al, 2011;Mező et al, 2011). These complexes readily bind to DNA through three binding modes: electrostatic interactions with the negatively charged sugar-phosphate back bone; intercalation between the base pairs of negatively charged DNA; and interactions within the two grooves of the DNA double helix.…”