Enzyme Design Using Steroid Template

Long alkyl chains with a catalytic group at one end can provide enough hydrophobic binding sites with fatty ester substrates to produce a rate enhancement. In the following case, 

Since the alkyl chains are very flexible and a strong hydrophobic area is never produced, a search for a more oriented network was needed. 

To overcome this difficulty J. P. Guthrie, from the University of Western Ontario, suggested the use of a planar, large, and rigid hydrophobic backbone, a steroid skeleton (191). 

For this he synthesized the following steroid molecule, androstane 3j8,1 IjS-diamino-17) (4)-imidazole. 

The presence of two ammonium ions makes the molecule water soluble enough to inhibit micelle formation under the experimental conditions. It should be recalled that bile acids are water soluble but form micelles. 

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