In enzymology, a sphingomyelin synthase (EC 2.7.8.27) is an enzyme that catalyzes the chemical reaction

a ceramide + a phosphatidylcholine ${\displaystyle \rightleftharpoons }$ a sphingomyelin + a 1,2-diacyl-sn-glycerol

Thus, the two substrates of this enzyme are ceramide and phosphatidylcholine, whereas its two products are sphingomyelin and 1,2-diacyl-sn-glycerol.

This enzyme belongs to the family of transferases, specifically those transferring non-standard substituted phosphate groups. The systematic name of this enzyme class is ceramide:phosphatidylcholine cholinephosphotransferase. Other names in common use include SM synthase, SMS1, and SMS2.

References

• Ullman MD, Radin NS (1974). "The enzymatic formation of sphingomyelin from ceramide and lecithin in mouse liver". J. Biol. Chem. 249 (5): 1506–12. PMID 4817756.
• Voelker DR, Kennedy EP (1982). "Cellular and enzymic synthesis of sphingomyelin". Biochemistry. 21 (11): 2753–9. doi:10.1021/bi00540a027. PMID 7093220.
• Huitema K, van den Dikkenberg J, Brouwers JF, Holthuis JC (2004). "Identification of a family of animal sphingomyelin synthases". EMBO J. 23 (1): 33–44. doi:10.1038/sj.emboj.7600034. PMC 1271672. PMID 14685263.
• Tafesse FG, Ternes P, Holthuis JC (2006). "The multigenic sphingomyelin synthase family". J. Biol. Chem. 281 (40): 29421–5. doi:10.1074/jbc.R600021200. PMID 16905542.
• Yamaoka S, Miyaji M, Kitano T, Umehara H, Okazaki T (2004). "Expression cloning of a human cDNA restoring sphingomyelin synthesis and cell growth in sphingomyelin synthase-defective lymphoid cells". J. Biol. Chem. 279 (18): 18688–93. doi:10.1074/jbc.M401205200. PMID 14976195.