MOLECULAR-CLONING AND EXPRESSION OF HUMAN GAL-BETA-1,3GALNAC ALPHA-2,3-SIALYLTRANSFERASE (HST3GAL-II)

A cDNA of human Gal beta 1,3GalNAc alpha 7,3-sialytransferase (hST3Gal II), which has been known to exhibit much more acceptor substrate pre ference for glycolipid than for O-linked oligosaccharides of glycoprot eins, was isolated from the human liver cDNA library by plaque hybridi zation using the cDNA of mouse ST3Gal II (mST3Gal II) cloned previousl y as a probe. Comparative analysis of this cDNA with mST3Gal II indica tes 89 and 94% homologies in the nucleotide and amino acid levels. res pectively, between the two sequences in the predicted ending region. N orthern analysis indicated that the expression of hSTSGal II mRNA is t issue-specific, it bring prominent in skeletal muscle and heart, while that in lung and kidney is very low. This enzyme expressed in COS cel ls showed a similiar activity with that of mSTSGal II. (C) 1996 Academ ic Press, Inc.