Intercalation agent, binding

Figure 4 A triple helix formed by a pyrimidine oligonucleotide (black ribbon) covalently linked to an intercalating agent (star). The intercalating agent binds at the triplex-duplex junction and can i) stabilize the triple-helical structure (acridine derivative, 7), ii) induce double strand cleavage (phenanthroline, 12), iii) photo-induce cleavage (ellipticine derivative, 13), iv) photo-induce cross-linking of the two DNA strands (psoralen, 10).

Cassytha filiformis L., mentioned earlier, contains aporphine alkaloids such as actin odaphnine, cassythine, and dicentrine, which effectively bind to DNA and behave as typical intercalating agents and interfere with the catalytic activity of topoisomerases (3,10,11). 

Significant increase in triplex stability can be achieved by using intercalating agents, either by conjugate attachment to the third strand TFO or as a separate adjunct ligand, if binding of this residue can preferentially stabilize a... 

Figure 8.15 Schematic representation of resin-bound dynamic combinatorial chemistry and structures of the family of intercalating DNA binding agents M, [54],...

In a study to establish the molecular basis for the diverse biological effects of ciyptolepine hydrochloride, Bonjean et al (55) observed that DNA is the primaiy target of ciyptolepine. They indicated that the alkaloid binds tightly to DNA and behaves as a typical intercalating agent. Their study also led to the discoveiy that ciyptolepine is a potent topoisomerase II inhibitor and a promising antitumor agent. 

A variety of inhibitors bind to DNA and thereby eliminate its template activity. Notable among these are the intercalating agents, which slip in between base pairs (e.g., the acridines, phenanthridium derivatives), and the an-thracyclines (daunorubicin, doxorubicin, and plicamycin). 

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