Enzymatic synthesis of trisialoganglioside by particulate fractions of rat liver.

Rat liver contains a particulate (membrane-bound) glycosyl transferase, concentrated in Golgi apparatus fractions, which catalyzes the synthesis of a trisialoganglioside from the ganglioside precursor disialohematoside (GD3). Sialic acid was not incorporated into exogenous GD1a from CMP-N-acetylneuraminic acid suggesting that GD1a is an endproduct of the monosialoganglioside pathway. Thus, the disialoganglioside pathway may be a primary source of trisialoganglioside and higher ganglioside homologs in adult rat liver.