Photocontrolled binding of cytochrome C to immobilized spiropyran

Agarose gel was modified with polyethyleneimine and β-l-3,3-dimethyl-6’-nitrospiro-(indoline-2,2’-2H-benzopyran)] propionic anhydride and the binding of cytochrome c was investigated. Cytochrome c was not retained on agarose modified only with polyethyleneimine. However, cytochrome c interacted with the immobilized spiropyran during illumination, but 0only a relatively small amount was bound to the immobilized spiropyran in the dark. The maximum difference of cytochrome c binding was observed at pH 6.8. Forty-six percent of cytochrome c bound on immobilized spiropyran in the column under visible light was released from the gel in the dark. This released cytochrome c showed the same spectrum and properties as those of native cytochrome c.