Computational and Experimental Study of Neuroglobin and Carbon Monoxide

Neuroglobin is a hexacoordinated protein normally found in the brain and nervous system that is closely related to myoglobin and hemoglobin. We have previously shown that neuroglobin (Ngb) reduces nitrite to nitric oxide 50x faster than myoglobin, 500x faster than hemoglobin, and tightly binds to carbon monoxide (CO) with an association rate that is 500x faster than hemoglobin. In the beginning phase of my research, I will be computationally analyzing structures of Ngb and mutants which improve these qualities. The computational simulation will be used to help predict the following questions: 1) Why are these Ngb mutants so much better at reducing nitrite than myoglobin and hemoglobin? 2) Why do they have a higher binding affinity to CO than hemoglobin? 3) What are the optimal mutants one can make to maximize nitrite reduction and CO binding? To analyze the structure of neuroglobin and the characteristics causing these phenomena, focusing on CO binding in this work, I am running 3 sets of molecular dynamic simulations of wild-type human Ngb (4mpm), reduced human Ngb (10j6), 4mpm mutants (C46A, C55A, H64L, H64Q), and 1OJ6 mutants (G46A, S55A, H64L, H64Q). I will also confirm my predictions with time-resolved absorption spectroscopy. These studies will help identify treatments for diseases involving low nitric oxide and carbon monoxide poisoning.