Microbial Nitroreductases: A versatile tool for biomedical and environmental applications.

Nitroreductases, enzymes found mostly in bacteria and also in few eukaryotes, use nicotinamide adenine dinucleotide (NADH) or nicotinamide adenine dinucleotide phosphate (NADPH) as a cofactor for their activity and metabolize an enormous list of diverse nitro group containing compounds. Nitroreductases capable of metabolizing nitroaromatic and nitro heterocyclic compounds have drawn great attention in recent years owing to their biotechnological, biomedical, environmental and human impact. These enzymes attracted medicinal chemists and pharmacologists because of their prodrug selectivity for activation/reduction of nitro compounds that wipe out pathogens/cancer cells, leaving the host/normal cells unharmed. It is applied in diverse fields of study like prodrug activation in treating cancer and leishmaniasis, designing fluorescent probes for hypoxia detection, cell imaging, ablation of specific cell types, biodegradation of nitro-pollutants and interpretation of mutagenicity of nitro compounds. Keeping in view the immense prospects of these enzymes and large number of research contributions in this area, the present review encompasses the enzymatic reaction mechanism, their role in antibiotic-resistance, hypoxia sensing, cell imaging, cancer therapy, reduction of recalcitrant nitro chemicals, enzyme variants and their specificity to substrates, reaction products and their applications. This article is protected by copyright. All rights reserved.