Covalent inhibition revealed by the crystal structure of the caspase-8/p35 complex
- 1 March 2001
- journal article
- Published by Springer Nature in Nature
- Vol. 410 (6827) , 494-497
- https://doi.org/10.1038/35068604
Abstract
Apoptosis is a highly regulated process that is crucial for normal development and homeostasis of multicellular organisms. The p35 protein from baculoviruses effectively prevents apoptosis by its broad-spectrum caspase inhibition. Here we report the crystal structure of p35 in complex with human caspase-8 at 3.0 A resolution, and biochemical and mutagenesis studies based on the structural information. The structure reveals that the caspase is inhibited in the active site through a covalent thioester linkage to p35, which we confirmed by gel electrophoresis, hydroxylamine treatment and mass spectrometry experiments. The p35 protein undergoes dramatic conformational changes on cleavage by the caspase. The repositioning of the amino terminus of p35 into the active site of the caspase eliminates solvent accessibility of the catalytic dyad. This may be crucial for preventing hydrolysis of the thioester intermediate, which is supported by the abrogation of inhibitory activity through mutations at the N terminus of p35. The p35 protein also makes conserved contacts with the caspase outside the active-site region, providing the molecular basis for the broad-spectrum inhibitory activity of this protein. We demonstrate a new molecular mechanism of caspase inhibition, as well as protease inhibition in general.Keywords
This publication has 27 references indexed in Scilit:
- Targeted expression of baculovirus p35 caspase inhibitor in oligodendrocytes protects mice against autoimmune-mediated demyelinationThe EMBO Journal, 2000
- Caspase inhibitorsCell Death & Differentiation, 1999
- Interaction of the Baculovirus Anti-apoptotic Protein p35 with Caspases. Specificity, Kinetics, and Characterization of the Caspase/p35 ComplexBiochemistry, 1998
- Cell Killing by the Drosophila Gene reaperScience, 1996
- Inhibition of ICE Family Proteases by Baculovirus Antiapoptotic Protein p35Science, 1995
- Inhibition of the Caenorhabditis elegans cell-death protease CED-3 by a CED-3 cleavage site in baculovirus p35 proteinNature, 1995
- The Baculovirus p35 Protein Inhibits Fas- and Tumor Necrosis Factor-induced ApoptosisPublished by Elsevier ,1995
- Apoptosis in the Pathogenesis and Treatment of DiseaseScience, 1995
- Mechanisms and Genes of Cellular SuicideScience, 1995
- Prevention of Apoptosis by a Baculovirus Gene During Infection of Insect CellsScience, 1991