In enzymology, a 2-hydroxyacylsphingosine 1-beta-galactosyltransferase (EC 2.4.1.45) is an enzyme that catalyzes the chemical reaction

UDP-galactose + 2-(2-hydroxyacyl)sphingosine ${\displaystyle \rightleftharpoons }$ UDP + 1-(beta-D-galactosyl)-2-(2-hydroxyacyl)sphingosine

Thus, the two substrates of this enzyme are UDP-galactose and 2-(2-hydroxyacyl)sphingosine, whereas its two products are UDP and 1-(beta-D-galactosyl)-2-(2-hydroxyacyl)sphingosine.

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:2-(2-hydroxyacyl)sphingosine 1-beta-D-galactosyl-transferase. Other names in common use include galactoceramide synthase^[1], uridine diphosphogalactose-2-hydroxyacylsphingosine, galactosyltransferase, UDPgalactose-2-hydroxyacylsphingosine galactosyltransferase, UDP-galactose:ceramide galactosyltransferase, and UDP-galactose:2-2-hydroxyacylsphingosine galactosyltransferase.

• Basu S, Schultz AM, Basu M, Roseman S (1971). "Enzymatic synthesis of galactocerebroside by a galactosyltransferase from embryonic chicken brain". J. Biol. Chem. 246 (13): 4272–9. PMID 5090043.
• Morell P, Radin NS (1969). "Synthesis of cerebroside by brain from uridine diphosphate galactose and ceramide containing hydroxy fatty acid". Biochemistry. 8 (2): 506–12. doi:10.1021/bi00830a008. PMID 5793706.