preferred_name: an N(4)-{beta-D-Gal-(1->4)-beta-D-GlcNAc-(1->2)-alpha-D-Man-(1->3)-[beta-D-Gal-(1->4)-beta-D-GlcNAc-(1->2)-alpha-D-Man-(1->6)]-beta-D-Man-(1->4)-beta-D-GlcNAc-(1->4)-beta-D-GlcNAc}-L-asparaginyl-[protein] + CMP-N-acetyl-beta-neuraminate = an N(4)-{alpha-Neu5Ac-(2->6)-beta-D-Gal-(1->4)-beta-D-GlcNAc-(1->2)-alpha-D-Man-(1->3)-[beta-D-Gal-(1->4)-beta-D-GlcNAc-(1->2)-alpha-D-Man-(1->6)]-beta-D-Man-(1->4)-beta-D-GlcNAc-(1->4)-beta-D-GlcNAc}-L-asparaginyl-[protein] + CMP + H(+)