The acceptor substrate specificity of human beta4-galactosyltransferase V indicates its potential function in O-glycosylation.

6GalNAc structural element, as found in O-linked core 2-, 4- and 6-based glycans, but not on substrates related to V-linked or blood group I-active oligosaccharides. These results suggest that beta4-GalT V may function in the synthesis of lacNAc units on O-linked chains, particularly in tissues which do not express beta4-GalT I, such as brain. -->
Substance Nomenclature: 0 (DNA, Complementary)
0 (Recombinant Proteins)
9013-90-5 (Lactalbumin)
EC 2.4.1.- (Galactosyltransferases)
Entry Date(s): Date Created: 19990601 Date Completed: 19990624 Latest Revision: 20190621
Update Code: 20240829
DOI: 10.1016/s0014-5793(99)00462-7
PMID: 10350056
Autor: van Die I; Department of Medical Chemistry, Vrije Universiteit, Amsterdam, The Netherlands. im.van_die.medchem@med.vu.nl, van Tetering A, Schiphorst WE, Sato T, Furukawa K, van den Eijnden DH
Jazyk: angličtina
Zdroj: FEBS letters [FEBS Lett] 1999 Apr 30; Vol. 450 (1-2), pp. 52-6.
DOI: 10.1016/s0014-5793(99)00462-7
Abstrakt: In order to assess the function of the different human UDP-Gal:GlcNAc beta4-galactosyltransferases, the cDNAs of two of them, beta4-GalT I and beta4-GalT V, were expressed in the baculovirus/insect cell expression system. The soluble recombinant enzymes produced were purified from the medium and used to determine their in vitro substrate specificities. The specific activity of the recombinant beta4-GalT V was more than 15 times lower than that of beta4-GalT I, using GlcNAc beta-S-pNP as an acceptor. Whereas beta4-GalT I efficiently acts on all substrates having a terminal beta-linked GlcNAc, beta4-GalT V appeared to be far more restricted in acceptor usage. Beta4-GalT V acts with high preference on acceptors that contain the GlcNAc beta1-->6GalNAc structural element, as found in O-linked core 2-, 4- and 6-based glycans, but not on substrates related to V-linked or blood group I-active oligosaccharides. These results suggest that beta4-GalT V may function in the synthesis of lacNAc units on O-linked chains, particularly in tissues which do not express beta4-GalT I, such as brain.
Databáze: MEDLINE
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