1. Institute of Biology/Molecular Biophysics, Humboldt-University Berlin, Invalidenstrasse 42, 10115 Berlin, Germany,
2. Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Strasse 2, 12489 Berlin, Germany,
3. Bayer Technology Services GmbH, Process Technology, Building E41, 51368 Leverkusen, Germany