Synthesis of the H-cluster framework of iron-only hydrogenase

• Published in: Nature Vol. 433; no. 7026; pp. 610 - 613
• Main Authors: Pickett, Christopher J, Tard, Cédric, Liu, Xiaoming, Ibrahim, Saad K, Bruschi, Maurizio, Gioia, Luca De, Davies, Siân C, Yang, Xin, Wang, Lai-Sheng, Sawers, Gary
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 10.02.2005; Nature Publishing Group
• Subjects: Analytical, structural and metabolic biochemistry; Binding Sites; Biological and medical sciences; Biomimetic Materials - chemical synthesis; Biomimetic Materials - chemistry; Biotechnology; Catalysis; Chemical Sciences; Chemical synthesis; Clostridium - enzymology; Desulfovibrio desulfuricans - enzymology; Electrochemistry; Enzymes and enzyme inhibitors; Fuel cells; Fundamental and applied biological sciences. Psychology; Hydrogen; Hydrogen - chemistry; Hydrogen production; Hydrogenase - chemical synthesis; Hydrogenase - chemistry; Iron; Iron - chemistry; Iron-Sulfur Proteins - chemical synthesis; Iron-Sulfur Proteins - chemistry; Lyases; Models, Molecular; Other; Oxidation-Reduction; Protons; Structure-Activity Relationship; Sulfur - chemistry; Hydrogenase; Enzyme; Active site; Iron; Oxidoreductases; Mechanism of action; Iron Sulfur cluster
• DOI: 10.1038/nature03298
• ISSN: 0028-0836

The metal-sulphur active sites of hydrogenases catalyse hydrogen evolution or uptake at rapid rates. Understanding the structure and function of these active sites-through mechanistic studies of hydrogenases, synthetic assemblies and in silico models-will help guide the design of new materials for hydrogen production or uptake. Here we report the assembly of the iron-sulphur framework of the active site of iron-only hydrogenase (the H-cluster), and show that it functions as an electrocatalyst for proton reduction. Through linking of a di-iron subsite to a {4Fe4S} cluster, we achieve the first synthesis of a metallosulphur cluster core involved in small-molecule catalysis. In addition to advancing our understanding of the natural biological system, the availability of an active, free-standing analogue of the H-cluster may enable us to develop useful electrocatalytic materials for application in, for example, reversible hydrogen fuel cells. (Platinum is currently the preferred electrocatalyst for such applications, but is expensive, limited in availability and, in the long term, unsustainable.)