Molecular cloning and functional expression of a fifth-type alpha 2,3-sialyltransferase (mST3Gal V: GM3 synthase)

Biochem Biophys Res Commun. 1998 Dec 9;253(1):170-5. doi: 10.1006/bbrc.1998.9768.


The cDNA encoding a new type of alpha 2,3-sialyltransferase (mST3Gal V) was cloned from mouse brain cDNA library by PCR-based cloning approach using a pair of degenerate primers deduced from the nucleotide sequence information of mouse ST3Gal III and IV. The predicted amino acid sequence of mST3Gal V showed 27.3% and 26.4% identity to mST3Gal III and IV, respectively. The recombinant soluble mST3Gal V fused with protein-A, which expressed in the culture media of COS-7 cells, showed activity toward lactosylceramide (LacCer), and synthesized GM3. The apparent Km value for LacCer was 9.3 microM. mST3Gal V did not exhibit any activity toward other substrates we tested in this study, including glycolipids, glycoproteins and disaccharides. The mST3Gal V cDNA transfected F28-7 cells, which express large amount of lactosylceramide and very small amount of GM3 at native stage, expressed a large amount of GM3. The ST3Gal V gene was strongly expressed in mouse brain and liver, which contained a large amount of ganglioside. The gene expression seemed to be coincident with ganglioside expression in mouse. Thus, we conclude that mST3Gal V is the fifth-type alpha 2,3-sialyltransferase carrying GM3 synthetic activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Line
  • Cloning, Molecular
  • DNA, Complementary / isolation & purification
  • Enzyme Activation / genetics
  • Gene Expression
  • Mice
  • Molecular Sequence Data
  • Organ Specificity / genetics
  • Sequence Analysis, DNA
  • Sialyltransferases / biosynthesis*
  • Sialyltransferases / genetics*
  • Sialyltransferases / isolation & purification


  • DNA, Complementary
  • Sialyltransferases
  • haematoside synthetase

Associated data

  • GENBANK/Y15003