Conformational control over proton-coupled electron transfer in metalloenzymes

Area of Science:

• Biochemistry
• Bioinorganic Chemistry
• Enzymology

Background:

• Metalloenzymes catalyze essential global geochemical and biochemical reactions, including dinitrogen reduction and water oxidation.
• These reactions involve complex electron and proton transfer, representing kinetically and thermodynamically challenging processes.
• Protein structural rearrangements are often rate-determining steps in metalloenzyme catalysis.

Purpose of the Study:

• To elucidate the interplay between protein structural changes and metallocofactor electronic structure in metalloenzymes.
• To clarify the mechanisms of proton-coupled electron transfer in key metalloenzymes.
• To synthesize decades of research on metalloenzyme structure-function relationships.

Main Methods:

• Review and synthesis of existing research on nitrogenase, photosystem II, and ribonucleotide reductase.
• Analysis of structure-function relationships in metalloenzyme catalysis.
• Investigation of proton-coupled electron transfer mechanisms.

Main Results:

• Nature utilizes macroscopic protein structural changes to control subatomic electronic changes in metallocofactors.
• Proton-coupled electron transfer mechanisms in key enzymes exemplify this structure-function interplay.
• Significant progress has been made in understanding these metalloenzyme linchpins.

Conclusions:

• Metalloenzymes leverage protein dynamics to achieve precise control over challenging catalytic transformations.
• Understanding these mechanisms is crucial for comprehending global biogeochemical cycles.
• Decades of research highlight the sophisticated interplay between molecular and electronic structures in enzyme function.