Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 22, 2002
Publication Date: N/A
Technical Abstract: Only a few enzymes have been examined in ionic liquids (ILs) to date. Initial results suggest that at least some enzymes tolerate ILs at least as well as conventional molecular solvents. Our work further explores the possibility that ILs provide a suitable (i.e., non-denaturing, non-inhibitory) environment for nonaqueous bioelectrocatalysis. We examine the spectral properties and peroxidase activity of the model oxidoreductase cytochrome c, as well as its active site analogs microperoxidase-11 and Fe (III)protoporphyrin (IX) chloride (hemin) solubilized in several types of hydrophobic, imidazolium-based ILs. Microperoxidase-11 is a mini-enzyme derived from cytochrome c containing a histidyl-coordinated heme c prosthetic group covalently attached through thioether bonds to an eleven-amino-acid peptide. In addition, a comparison is made of the peroxidase activity of these model enzymes in ILs with that observed in conventional molecular solvents.