Models, cytochrome c oxidase

8 Collman, J. R, Devaraj, N. K., Decreau, R. A., et al., A cytochrome c oxidase model catalyzes oxygen to water reduction under rate-limiting electron flux , Science 2007, 315, 1565-1568. 

Very sophisticated model compounds such as the examples detailed here shed tremendous light on these complex natural enzymes because they allow chemists to control and understand the systems in detail. However, the difficulty in constructing these models cannot be overstated - Collman s compound takes 32 convergent synthetic steps to prepare  

Vitamin B12 and its active form coenzyme, (5 -deoxyadenosylcobalamin), are tetrapyrrole-based cobalt-containing macrocyclic complexes containing the 15-membered corrin ring. They act in concert with an apoenzyme (a large protein that binds simultaneously the cofactor and the substrate in order to carry out a variety of mutase enzymatic transformations, generally involving radical-based 

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Collman JP, Decreau RA, Yan Y, Yoon J, Solomon El. 2007a. Intramolecular single-turnover reaction in a cytochrome c oxidase model bearing a Tyr244 mimic. J Am Chem Soc 129 5794. 

Cytochrome c Oxidase Model Compounds and Associated Analytical Techniques... 

In 2004, Kenneth Karlin and co-workers published an extensive review of cytochrome c oxidase model compounds. Hundreds of CcO models exist, with more being synthesized and studied into the current time. These can be broken down into a number of categories as Karlin s group does in the 2004... 

Figure 7.43 Cytochrome c oxidase model complexes, [(Porphyrin)Fe -OH-Cu"(N4)], as synthesized in reference 149.

Franceschi, F., Gullotti, M., Monzani, E., Casella, L., and Papaetthymiou, V., 1996, Cytochrome c oxidase models, Chem. Commun. 1645nl646. 

See E. Kim et al. (2003) Proc. Natl. Acad. Sci., vol. 100, p. 3623 - Superoxo, p-peroxo, and p-oxo complexes from heme/02 and heme-CU/O2 reactivity copper ligand influences on cytochrome c oxidase models . 

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