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Three-dimensional structure of a purple lipoxygenase
E Skrzypczak-Jankun1, R A Bross, R T Carroll
1Department of Chemistry, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA. ejankun@protein.wo.utoledo.edu
Journal of the American Chemical Society
|November 1, 2001
Summary
Researchers determined the crystal structure of soybean lipoxygenase-3, revealing an iron-peroxide complex. This finding offers insights into polyunsaturated fatty acid metabolism and enzyme catalysis.
Area of Science:
- Biochemistry
- Enzymology
- Structural Biology
Background:
- Polyunsaturated fatty acid metabolism is crucial and primarily regulated by prostaglandin H synthase and lipoxygenase enzymes.
- Understanding the structural basis of lipoxygenase function is key to elucidating fatty acid metabolic pathways.
Purpose of the Study:
- To determine the crystal structure of the product-oxidized purple form of soybean lipoxygenase-3.
- To investigate the nature of the chromophore and alterations in the iron site during catalysis.
- To identify key amino acid residues involved in lipoxygenase activity.
Main Methods:
- X-ray crystallography at 2.0 A resolution.
- Structural analysis of soybean lipoxygenase-3.
Main Results:
- The crystal structure revealed a metastable product-oxidized purple form of soybean lipoxygenase-3.
- A novel iron-peroxide complex was identified as a potential reaction intermediate.
- Significant changes in the iron site and an unexpected binding mode were observed.
- Specific amino acid residues potentially involved in catalysis and selectivity were identified.
Conclusions:
- The determined structure provides the first atomic view of a fatty acid-lipoxygenase complex.
- The findings illuminate the catalytic mechanism and selectivity of lipoxygenases.
- This structural information can guide future research on enzyme function and drug design.
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