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 and the NADH as cofactor.
The activity of DDase is influenced by several factors as
- alkyl chain length of the sphingoid base and fatty acid
- The stereochemistry of the sphingoid base
- the nature of the headgroup, with the highest activity with dihydroceramide, but some activity with dihydroglucosylceramide
- 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-octanamide, is the inhibitor DDase activity.