Unsaturated fatty acyl chains, like sphingomyelin,
are the preferred substrate for £\-toxin
¡CThe conformational change
in the active site is triggered by the binding of calcium ion.
¡CTailgroups fit into hydrophobic
grooves on the enzyme surface.
One tailgroup
requires at least one cis-double bond about halfway
along
its length to interact maximally with the surface.
