The third lecture focuses on biochemical reactions involvingCO2. Indeed, living organisms possess fascinating enzymatic systems - the natural catalysts of biological reactions - for transformingCO2. Studying them helps us understand the natural strategies for activatingCO2, developed over billions of years of evolution. At the same time, these systems provide the chemist with unique sources of inspiration for the development of novel chemical catalysts.
In this lecture, we discuss the following systems in terms of their structural properties and reaction mechanisms: (1) Rubisco, ribulose 1,5-bisphosphate carboxylase, an essential enzyme forCO2 fixation and its incorporation into sugar synthesis; (2) the various classes of formate dehydrogenases, which interconvertCO2 and formic acid using molybdenum- and tungsten-based active sites; (iii) the various classes of CO dehydrogenases, which interconvertCO2 and carbon monoxide (CO) using unusual metal sites based on nickel and iron, or molybdenum and copper.
This knowledge has already led chemists to develop bioinspired metal complexes that mimic the structure and reactivity of these metal sites. This bioinspired chemistry approach, illustrated by some original examples in this lecture, should see fruitful developments in the years to come.
