FIG. 5.

Acyl-CoA-dependent ceramide synthase has a strong preference for longer-chain fatty acyls. Ceramide synthase activity was measured by the incubation of crude membranes with [³H]DHS in the presence of acyl-CoA as described in Materials and Methods. (A) The reaction was linear for at least 30 min. (B) The formation of the product that comigrated with the ceramide standard, indicated by a broken circle, upon silica gel TLC was dependent on the addition of acyl-CoA and was inhibited by 10 μM australifungin and 100 μM fumonisin B₁. (C) Crude membranes from the screening strain Y388-2 were assayed for ceramide formation after incubation with 10 μM acyl-CoAs containing saturated fatty acyls of various lengths.