Biomaterial Database

Kinetic study of human beta-1,4-galactosyltransferase expressed in E. coli. 1993

K Nakazawa, and K Furukawa, and H Narimatsu, and A Kobata

Department of Microbiology, Keio University School of Medicine, Tokyo.

Recombinant beta-1,4-galactosyltransferase which synthesizes the Gal beta 1-->4GlcNAc group of glycoprotein sugar chains was obtained as a soluble form from Escherichia coli by transfection of the human cDNA lacking the transmembrane segment. Kinetic study revealed that the soluble transferase has the same apparent Km values toward sugar nucleotide and sugar acceptors as those of mouse membrane-bound beta-1,4-galactosyltransferase previously characterized [Nakazawa et al. (1991) Eur. J. Biochem. 196, 363-368]. However, the Vmax value of this transferase was low when compared to that of the mammalian transferase, probably due to the instability of the transferase caused by the lack of protein glycosylation. The soluble transferase was purified from the E. coli lysates almost to homogeneity by chromatography on DEAE-Sepharose and alpha-lactalbumin-Sepharose columns. Using this purified transferase, the acceptor specificity of the transferase has been studied. The results showed that the transferase has apparent Km values of 170, 190, and 830 microM for agalacto-poly-N-acetyllactosamine, lacto-N-triose II, and lacto-N-triaosylceramide, respectively, but has apparently no activity toward glucosylceramide. These results suggest that the beta-1,4-galactosyltransferase may be involved in the synthesis of poly-N-acetyllactosamine, lacto-N-neotetraose, and probably lacto-N-neotetraosylceramide in addition to the formation of the Gal beta 1-->4GlcNAc group of glycoprotein sugar chains and lactose.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009237	N-Acetyllactosamine Synthase	The A protein of the lactose synthase complex. In the presence of the B protein (LACTALBUMIN) specificity is changed from N-acetylglucosamine to glucose. EC 2.4.1.90.	N-Acetyllactosamine Synthetase,UDP Galactose Acetylglucosamine Galactosyltransferase,N-Acetylglucosamine beta-D-Galactosyltransferase,UDP Galactose-N-Acetylglucosamine Galactosyltransferase,beta-1,4-Galactosyltransferase,Galactosyltransferase, UDP Galactose-N-Acetylglucosamine,N Acetylglucosamine beta D Galactosyltransferase,N Acetyllactosamine Synthase,N Acetyllactosamine Synthetase,Synthase, N-Acetyllactosamine,Synthetase, N-Acetyllactosamine,UDP Galactose N Acetylglucosamine Galactosyltransferase,beta 1,4 Galactosyltransferase,beta-D-Galactosyltransferase, N-Acetylglucosamine
D009844	Oligosaccharides	Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.	Oligosaccharide
D011134	Polysaccharides	Long chain polymeric CARBOHYDRATES composed of MONOSACCHARIDES linked by glycosidic bonds.	Glycan,Glycans,Polysaccharide
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, DNA
D002240	Carbohydrate Sequence	The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.	Carbohydrate Sequences,Sequence, Carbohydrate,Sequences, Carbohydrate
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D006023	Glycoproteins	Conjugated protein-carbohydrate compounds including MUCINS; mucoid, and AMYLOID glycoproteins.	C-Glycosylated Proteins,Glycosylated Protein,Glycosylated Proteins,N-Glycosylated Proteins,O-Glycosylated Proteins,Glycoprotein,Neoglycoproteins,Protein, Glycosylated,Proteins, C-Glycosylated,Proteins, Glycosylated,Proteins, N-Glycosylated,Proteins, O-Glycosylated
D006028	Glycosphingolipids	Lipids containing at least one monosaccharide residue and either a sphingoid or a ceramide (CERAMIDES). They are subdivided into NEUTRAL GLYCOSPHINGOLIPIDS comprising monoglycosyl- and oligoglycosylsphingoids and monoglycosyl- and oligoglycosylceramides; and ACIDIC GLYCOSPHINGOLIPIDS which comprises sialosylglycosylsphingolipids (GANGLIOSIDES); SULFOGLYCOSPHINGOLIPIDS (formerly known as sulfatides), glycuronoglycosphingolipids, and phospho- and phosphonoglycosphingolipids. (From IUPAC's webpage)	Asialoganglioside,Asialogangliosides,Glycosphingolipid,Sphingoglycolipid,Sphingoglycolipids