Self assembled metalloproteins

Gray HB, Winkler JR (1996) Electron transfer in proteins. Annu Rev Biochem 65 537 Fedurco M (2000) Redox reactions of heme-containing metalloproteins dynamic effects of self-assembled monolayers on thermodynamics and kinetics of cytochrome c electron-transfer reactions. Coord Chem Rev 209 263... 

M. Enomoto, T. Aida, Self-Assembly of a Copper-Ligating Dendrimer That Provides a New Non-Heme Metalloprotein Mimic Dendrimer Effects on Stability of the Bis(mu-oxo)dicopper(lll) Core , J. Am. Chem. Soc., 121,874 (1999)... 

The formation of three-stranded, helical (synthetic) proteins has been shown to be influenced by metal-ion binding to ligands that form part of the component peptide strands. In one study of this type, a 15-residue amphiphilic peptide containing a 2,2 -bipyridine derivative situated at the N-terminus was demonstrated to self-assemble spontaneously in the presence of selected transition metal ions to form a 45-residue metalloprotein with a triple-helical, coiled-coil structure. 

Ghadiri and coworkers have refined this idea to such an extent that it has been possible to synthesize a Ru metalloprotein with a well-defined metal-binding site. [10] This was achieved with peptide 7, which had two potential metal-binding sites - an A-terminal bpy and an imidazole nitrogen atom of a histidine residue close to the C-terminus of 7 - and should favor a helical structure. Incorporation of the bpy functionality at the A-terminus of each peptide allowed direction of the self-assembly of three peptides with a Ru ion as... 

These are only a few examples indicating the scope of this emerging area of research at the interface of peptide and protein chemistry and coordination chemistry. The synthesis of metal-binding metalloproteins and the introduction of redox-active metal centers into artificial proteins by self-assembly processes is surely only the beginning. One can certainly think of extending this approach to the incorporation of substrate-binding enzymatic func-... 

Keywords Bioinorganic chemistry Metalloprotein Self-assembly protein Coordination chemistry Protein cage... 

The defined architecture of the metalloprotein ferritin, a natural complex of iron oxide, is found in almost all domains of life and has been used as a constrained reaction vessel for the synthesis of a number of non-natural metal oxides [28, 34]. The protein ferritin consists of 24 subunits that self-assemble into a cage, consisting of a threefold hydrophilic channel coordinated to a fourfold hydrophobic channel [20, 28]. In biology, Fe(ll) is introduced into the core of the apoprotein through its hydrophiUc charmels where the ferrous ion is catalytically oxidized to a less-soluble ferric ion, Fe(lll) [20]. The ferric ion then undergoes a series of hydrolytic polymerizations to form the insoluble ferric oxyhydroxide mineral (ferrihydrite), which is physically constrained by the size of the protein cage (12 nm outer diameter, 8nm inner diameter) [35]. The enzyme ferrous oxidase is coordinated within the protein cage, the interior and exterior of which is electrostatically dissimilar, to produce spatially defined minerals. 

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