a ganglioside Ac-O-9-GD1a + CMP + H(+) => CMP-N-acetyl-9-O-acetyl-beta-neuraminate + a ganglioside GM1
a ganglioside ac-o-9-gd1a + cmp + h(+) => cmp-n-acetyl-9-o-acetyl-beta-neuraminate + a ganglioside gm1