Modeling and proposed mechanism of two radical scavengers through docking to curtail the action of ribonucleotide reductase

Abstract

Sampath Natarajan* and Rita Mathews

Ribonucleotide reductase (RR) is a ubiquitous cytosolic enzyme required for DNA synthesis and repair in all living cells. Therefore, the crucial role of this enzyme in cell division makes it a potential target for designing drugs that inhibit cell growth for cancer therapy. An increased interest in RR as a target for cancer therapy has been documented since the discovery that human RR is regulated by p53 enzyme and that a mutation in p53 leads to several forms of cancer. Cell proliferation stops if normal RR is inhibited. A new strategy to kill the cancer cells would be using specific inhibitors that inhibit the action of RR enzyme. The inhibitor must be a radical scavenger which destroys the tyrosyl radical or an iron metal scavenger (which affects iron center). In this view, modeling studies on human RR-R2 were done to understand its interaction with radical scavengers, flavin (FLA) and phenosafranine (PHE) through docking since they have good reductive property. Radical scavengers are active against RR enzymes at anaerobic condition and their radical scavenging mechanism has been proposed. In aerobic condition RR enzyme will reproduce the radicals and then the radical scavengers fail to act as drug. So, the metal scavengers may be better than the radical scavengers to curtail the action of RR enzyme.