The use of redox enzymes as biocatalysts has been limited, mainly due to their instability which arises from the need for an exogeneous oxidant, typically hydrogen or alkyl peroxides. We are interested in examining the properties of haem proteins with a view to using these proteins as biosensors and biocatalysts. By examining the surface properties of the immobilisation matrix and of the protein of interest, we have established a systematic means of evaluating the potential of a porous support to immobilise enzymes with retention of catalytic activity. Chloroperoxidase was immobilised on to a mesoporous silicate and re-used 20 times without loss of activity. The electrochemical and biocatalytical properties of hemin and a range of haem proteins, (myoglobin, haemoglobin, cytochrome c, horseradish peroxidase and chloroperoxidase) was then examined in nonaqueous solvents. The thermodynamics of reduction of these proteins indicates that each protein needs to be examined independently, with no discernible trends evident for a particular enyzme in a range of solvents. Wih enzymes such as horseradish peroxidase where the haem is noncovalently bound to the protein, it is apparent that the haem is partially removed from the haem binding pocket.