Characterization of recombinant human glucuronyltransferase I involved in the biosynthesis of the glycosaminoglycan-protein linkage region of proteoglycans.
We characterized the recombinant glucuronyltransferase I (GlcAT-I) involved in the glycosaminoglycan-protein linkage region biosynthesis. The enzyme showed strict specificity for Galbeta1-3Galbeta1-4Xyl, exhibiting negligible incorporation into other galactoside substrates including Galbeta1-3Galbeta1-O-benzyl, Galbeta1-4GlcNAc and Galbeta1-4Glc. A comparison of the GlcAT-I with another beta1,3-glucuronyltransferase involved in the HNK-1 epitope biosynthesis revealed that the two beta1,3-glucuronyltransferases exhibited distinct and no overlapping acceptor substrate specificities in vitro. Nevertheless, the transfection of the GlcAT-I cDNA into COS-1 cells induced the significant expression of the HNK-1 epitope. These results suggested that the high expression of the GlcAT-I gene rendered the cells capable of synthesizing the HNK-1 epitope.
Tone
Y
Y
Department of Biochemistry, Kobe Pharmaceutical University, 4-19-1 Motoyamakita-machi, Higashinada-ku, Kobe, Japan.
Kitagawa
H
H
Imiya
K
K
Oka
S
S
Kawasaki
T
T
Sugahara
K
K
D000818:Animals; D019556:COS Cells; D014453:Glucuronosyltransferase / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000378:metabolism*; D006801:Humans; D011506:Proteins / Q000378:metabolism; D011509:Proteoglycans / Q000096:biosynthesis* / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013379:Substrate Specificity
D006025:Glycosaminoglycans; D011506:Proteins; D011509:Proteoglycans; D011994:Recombinant Proteins; C111364:galactosylgalactoylxylosylprotein 3-beta-glucuronosyltransferase; D014453:Glucuronosyltransferase