Published Online: 23 SEP 2005
Copyright © 2001 John Wiley & Sons, Ltd. All rights reserved.
How to Cite
Sjöberg, B.-M. and Sahlin, M. 2005. Radical Enzymes. eLS. .
- Published Online: 23 SEP 2005
Radical enzymes harbour a stable free radical in their polypeptide chain, which participates in catalysis. A growing number of enzymes are known to require a posttranslationally generated free radical for their proper functioning. The radical is generally used to remove a hydrogen atom from an unreactive position in the substrate, activating the substrate to undergo difficult chemistry. Some radical enzymes have unexpectedly been found to harbour a stable radical on an amino acid side-chain that is distinct from the side-chains of the active site region; during catalysis, the stable free radical interacts with the active site via electron or radical transfer and between turnovers it serves as a radical sink.
- tyrosyl radical;
- glycyl radical;
- cysteinyl radical;
- ribonucleotide reductase