Research Projects

Biomimetic study of di-heme enzymes such as bCcP, MauG, and RoxA will be performed in order to understand structure-activity relationships at the molecular level and also to reproduce the enzymatic functions in the laboratory for sustainable development. Di-heme enzymes are not simple heme assemblies but indeed sophisticated devices. Each heme unit behaves like a domain in multi-domain proteins and also has specific functions, including a regulatory one. Diheme enzymes are also found to be much superior to that of mono-heme enzymes. The orientation of two heme units in space and nature of bridge will have important roles to play in defining the reaction type and enzymatic functionality by allowing substrate binding and thereby control the catalytic cycle. Heme-heme interaction and cooperativity appear to be critical for high catalytic efficiency of diheme enzymes which require extensive investigation. The enzymatic reaction mechanism would be elucidated by means of active site analogs and information obtained will be useful to understand Nature’s sophisticated design to develop highly efficient diheme catalysts. The bis-Fe(IV) intermediate displays extraordinary stability with a half-life of several minutes. Indeed, all these diheme enzymes bCcP, MauG, and RoxA are going through the similar Fe(IV)=O reactive intermediates during the catalysis. The local electric field (LEF) of one heme might influence the stability and reactivity of other heme centre. The present proposal is also aimed to isolate the hitherto unknown bis-Fe(IV) oxo and its analogs with metal ions such as Cr, Mn and Co and investigation of their stability and reactivity. High valent bis-M(IV)oxo species will be utilized for a variety of chemical transformations having wide practical applicability. The presence of two heme centers and cooperativity therein will modulate catalytic activity and efficiency significantly as also observed in diheme enzymes. Suitable catalysts will be designed to destroy the reactive oxygen species (ROS) almost immediately and efficiently which might provide a sustainable solution for aging and age-related diseases. Also, the oxidative decomposition of the rubber/polymer will be investigated using synthetic rubber oxygenase analog, a long waited natural and sustainable solutions towards environmental pollution. The research will utilize a wide range of spectroscopic, theoretical, and chemical techniques to probe structure-function relationships to gain mechanistic insight, and also to address fundamental questions of relevance to chemistry and biology. No such studies on diheme enzymes have been demonstrated earlier. Most importantly, the outcome of such investigation will also provide practical solutions for future sustainable development and industrial application.