Skip to main content
. Author manuscript; available in PMC: 2017 Jan 1.
Published in final edited form as: Immunol Rev. 2016 Jan;269(1):145–161. doi: 10.1111/imr.12344

Fig. 2. Sialic acid modifying enzymes discussed in this review.

Fig. 2

Sialic acids are conjugated to cytidine monophosphate by CMP-5-N-acetylneuraminic acid synthetase. The CMP-sialic acid conjugates act as high energy donors for sialyltransferase reactions. There are numerous sialyltransferases in the mammalian genome, each specific for a particular linkage. ST6GAL1 is discussed in the review. Sialidases cleave sialic acids from glycans. Sialic acid acetyl esterase (SIAE) in an enzyme - perhaps one of many - that removes the 9-O-acetyl group from sialic acid bearing gycans. The identity of sialic acid O-acetyl transferases (SOAT) has not been established. CASD1 is a strong candidate for such an enzyme, but it is likely that multiple SOAT enzymes exist that add 9-O-acetyl group to specific sialic acid bearing glycans and/or the CMP-sialic acid precursor.