Reaction catalyzed by beta-galactoside alpha-2,3-sialyltransferase (2.4.3.4)
+
=
+
CMP-N-acetylneuraminate
+
4-nitrophenyl beta-D-Gal-(1->3)-alpha-D-GalNAc
=
CMP
+
4-nitrophenyl alpha-Neu5Ac-(2->3)-beta-D-Gal-(1->3)-alpha-D-GalNAc