Letters to Nature

Nature 417, 463-468 (23 May 2002) | doi:10.1038/417463a; Received 11 November 2001; Accepted 4 March 2002

The catalytic pathway of horseradish peroxidase at high resolution

Gunnar I. Berglund1,2, Gunilla H. Carlsson1,2, Andrew T. Smith3, Hanna Szöke1,4, Anette Henriksen4,5 & Janos Hajdu1

  1. Department of Biochemistry, Uppsala University, Biomedical Center, Box 576, S-751 23 Uppsala, Sweden
  2. School of Biological Sciences, University of Sussex, Brighton BN1 9QG, UK
  3. Protein Structure Group, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 København, Denmark
  4. Present addresses: Lawrence Livermore National Laboratory, PO Box 808, L-41, Livermore, California 94551, USA (H.S.); Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2100 Valby, Denmark (A.H.).
  5. These authors contributed equally to this work

Correspondence to: Janos Hajdu1 Correspondence and requests for materials should be addressed to J.H. (e-mail: Email: janos@xray.bmc.uu.se).

A molecular description of oxygen and peroxide activation in biological systems is difficult, because electrons liberated during X-ray data collection reduce the active centres of redox enzymes catalysing these reactions1, 2, 3, 4, 5. Here we describe an effective strategy to obtain crystal structures for high-valency redox intermediates and present a three-dimensional movie of the X-ray-driven catalytic reduction of a bound dioxygen species in horseradish peroxidase (HRP). We also describe separate experiments in which high-resolution structures could be obtained for all five oxidation states of HRP, showing such structures with preserved redox states for the first time.