Photoactivatable myoglobin containing a DNA oligonucleotide as a structural anchor was designed by using the reconstitution of artificial heme moieties containing Ru(3+) ions. This semisynthetic DNA-enzyme conjugate was successfully used for the oxidation of peroxidase substrates by using visible light instead of H(2)O(2) for the activation. The DNA anchor was utilized for the immobilization of the enzyme on the surface of magnetic microbeads. Enzyme activity measurements not only indicated undisturbed biofunctionality of the tethered DNA but also enabled magnetic separation-based enrichment and recycling of the photoactivatable biocatalyst.