label: sphingolipid 8-(E/Z)-desaturase activity
label_lc: sphingolipid 8-(e/z)-desaturase activity
description: "Catalysis of the reaction: an N-acyl-(4R)-4-hydroxysphinganine + 2 Fe(II)-[cytochrome b5] + 2 H+ + O2 = a (4R,8E)-4-hydroxysphingenine ceramide + 2 Fe(III)-[cytochrome b5] + 2 H2O or an N-acyl-(4R)-4-hydroxysphinganine + 2 Fe(II)-[cytochrome b5] + 2 H+ + O2 = (4R,8Z)-4-hydroxysphing-8-enine ceramide + 2 Fe(III)-[cytochrome b5] + 2 H2O. This results in the formation of a double bond between C8 and C9 of the long chain base of a sphingolipid."