Dihydroceramide desaturase

Dihydroceramide desaturase is the enzyme involved in the conversion of dihydroceramide into ceramide by inserting the 4,5-trans-double bond to the sphingolipid backbone of dihydroceramide. DDase require the O
2
and the NAD(P)H as cofactor.[1]

Dihydroceramide desaturase
Identifiers
EC no.1.14.19.17
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
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The activity of DDase is influenced by several factors as

  1. alkyl chain length of the sphingoid base (in the order C18 > C12 > C8) and fatty acid (C8 > C18)
  2. The stereochemistry of the sphingoid base (D-erythro- > L-threo-dihydroceramides)
  3. the nature of the headgroup, with the highest activity with dihydroceramide, but some (approximately 20%) activity with dihydroglucosylceramide
  4. The ability to utilize alternative reductants like ascorbic acid could substitute for a reduced pyridine nucleotide, but it act as inhibitory at higher concentrations.

N-[(1R,2S)-2-hydroxy-1-hydroxymethyl-2-(2-tridecyl-1-cyclopropenyl)ethyl]octanamide (GT11), is the inhibitor DDase activity.[2]

References