Description
The enzyme, which has been characterized from multiple organisms including the moss Physcomitrella patens, the marine microalga Rebecca salina, and the filamentous fungus Mortierella alpina, introduces a cis double bond at the 5-position in 20-carbon polyunsaturated fatty acids incorporated in a glycerolipid that contain a Δ8 double bond. The enzyme contains a cytochrome b5 domain that acts as the direct electron donor to the active site of the desaturase, and does not require an external cytochrome.
Reaction
(1) an (8Z,11Z,14Z)-icosa-8,11,14-trienoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (5Z,8Z,11Z,14Z)-icosatetra-5,8,11,14-tetraenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O; (2) an (8Z,11Z,14Z,17Z)-icosa-8,11,14,17-tetraenoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (5Z,8Z,11Z,14Z,17Z)-icosa-5,8,11,14,17-pentaenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Download Datasheet