Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
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Drug
Enzyme
Compound
Query: EC:3.2.1.23 (
beta-galactosidase
)
14,648
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
An assay method was devised for measuring the activity of
galactosyltransferase I
(
UDP-D-galactose:D-xylose galactosyltransferase
), which is one of the enzymes synthesizing the linkage region between the core protein and glycosaminoglycan chains of proteoglycan. For this method, the reaction mixture contained a fluorescent substrate, 4-methylumbelliferyl-beta-D-xyloside as an acceptor, UDP-galactose as a donor and D-galactal as a competitive inhibitor of endogenous
beta-galactosidase
in the enzyme solution. The reaction mixture was incubated at 37 degrees C with enzyme solution prepared from an extract of cultured cells, and galactosyl-xylosyl-4-methylumbelliferone was produced as a reaction product. Measurement of
galactosyltransferase I
activity was performed by separation and quantitative analysis of this reaction product using high-performance liquid chromatography. Utilizing this method, easier and more sensitive detection of
galactosyltransferase I
activity in a cell-free system became possible. Application of the method revealed that cultured human skin fibroblasts contained
galactosyltransferase I
activity.
...
PMID:A method for determination of galactosyltransferase I activity synthesizing the proteoglycan linkage region. 783 58
A cDNA encoding a novel galactosyltransferase was identified based on BLAST analysis of expressed sequence tags, and the cDNA clones were isolated from a human melanoma line library. The new cDNA sequence encoded a type II membrane protein with 327 amino acid sequence and showed 38% homology to the Caenorhabditis elegans sqv-3 gene involved in the vulval invagination and oocyte development. Extracts from L cells transfected with the galactosyltransferase cDNA in an expression vector and a fusion protein with protein A exhibited marked galactosyltransferase activity specific for p-nitrophenyl-beta-D-xylopyranoside. Moreover, transfection with the cloned cDNA restored glycosaminoglycan synthesis of
galactosyltransferase I
-deficient Chinese hamster ovary mutant pgsB-761 cells. Analysis of the enzyme product by
beta-galactosidase
digestion, mass spectroscopy, and NMR spectroscopy revealed that the reaction product was formed via beta-1,4 linkage, indicating that the enzyme is
galactosyltransferase I
(
UDP-galactose:O-beta-D-xylosylprotein 4-beta-D-galactosyltransferase
,
EC 2.4.1.133
) involved in the synthesis of the glycosaminoglycan-protein linkage region of proteoglycans.
...
PMID:Human homolog of Caenorhabditis elegans sqv-3 gene is galactosyltransferase I involved in the biosynthesis of the glycosaminoglycan-protein linkage region of proteoglycans. 1043 55
