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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
1.14.99.5 created 1972, modified 1986, modified 2000, deleted 2000 1.14.99.6 created 1972, modified 2000, deleted 2000 1.14.99.8 created 1972, deleted 1984 1.14.99.13 created 1972, deleted 1984 1.14.99.16 created 1972, deleted 2002 1.14.99.17 created 1972, deleted 1976 1.14.99.18 created 1976, modified 1999, deleted 2003 1.14.99.25 created 1986, deleted 2000
