Bacterial tyrosinases and their inhibitors.

Bacterial tyrosinase is a copper-containing metalloenzyme with diverse physio-chemical properties, that have been identified in various bacterial strains, including actinobacteria and proteobacteria. Tyrosinases are responsible for the rate-limiting catalytic steps in melanin biosynthesis and enzymatic browning. The physiological role of bacterial tyrosinases in melanin biosynthesis has been harnessed for the production of coloring and dyeing agents. Additionally, bacterial tyrosinases have the capability of cross-linking activity, demonstrated material functionalization applications, and applications in food processing with varying substrate specificities and stability features. These characteristics make bacterial tyrosinases a valuable alternative to well-studied mushroom tyrosinases. The key feature of substrate specificity of bacterial tyrosinase has been exploited to engineer biosensors that have the ability to detect the minimal amount of different phenolic compounds. Today, the world is facing the challenge of multi-drugs resistance in various diseases, especially antibiotic resistance, skin cancer, enzymatic browning of fruits and vegetables, and melanogenesis. To address these challenges, medicinal scientists are developing novel chemotherapeutic agents by inhibiting bacterial tyrosinases. To serve this purpose, heterocyclic compounds are of particular interest due to their vast spectrum of biological activities and their potential as effective tyrosinase inhibitors. In this chapter, a plethora of research explores applications of bacterial tyrosinases in different fields, such as the production of dyes and pigments, catalytic applications in organic synthesis, bioremediation, food and feed applications, biosensors, wool fiber coating and the rationalized synthesis, and structure-activity relationship of bacterial tyrosinase inhibitors.