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EC 1.14.19.29 Details
show Brenda entryEC number
1.14.19.29
Accepted name
sphingolipid 8-(E/Z)-desaturase
Reaction
(1) a (4R)-4-hydroxysphinganine ceramide + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4R,8E)-4-hydroxysphing-8-enine ceramide + 2 ferricytochrome b5 + 2 H2O;;(2) a (4R)-4-hydroxysphinganine ceramide + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4R,8Z)-4-hydroxysphing-8-enine ceramide + 2 ferricytochrome b5 + 2 H2O
Other name(s)
8-sphingolipid desaturase (ambiguous),
8 fatty acid desaturase (ambiguous),
DELTA8-sphingolipid desaturase (ambiguous)
Systematic name
(4R)-4-hydroxysphinganine ceramide,ferrocytochrome b5:oxygen oxidoreductase (8,9 cis/trans-dehydrogenating)
Comment
The enzymes from higher plants convert sphinganine, 4E-sphing-4-enine and phytosphinganine into E/Z-mixtures of Δ8-desaturated products displaying different proportions of geometrical isomers depending on plant species. The nature of the actual desaturase substrate has not yet been studied experimentally. The enzymes contain an N-terminal cytochrome b5 domain that acts as the direct electron donor to the active site of the desaturase [1]. The homologous enzymes from some yeasts and diatoms, EC 1.14.19.18, sphingolipid 8-(E)-desaturase, act on sphing-4-enine ceramides and produce only the trans isomer.
History
created 2015
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1 Oxidoreductases
1.1 Acting on the CH-OH group of donors
1.4.99.1 D-amino-acid dehydrogenase
