The substrate specificity of tocopherol cyclase Original Research Article

The substrate specificity of the enzyme tocopherol cyclase from the blue-green algae Anabaena variabilis (Cyanobacteria) was investigated with 11 substrate analogues revealing the significance of three major recognition sites: (i) the OH group at C(1) of the hydroquinone, (ii) the (E) configuration of the double bond, and (iii) the length of the lipophilic side chain. Experiments with two affinity matrices suggest that substrates approach the enzymeʹs active site with the hydrophobic tail.