Disease relevance of N-acetyllactosamine

• Relationship of the terminal sequences to the length of poly-N-acetyllactosamine chains in asparagine-linked oligosaccharides from the mouse lymphoma cell line BW5147. Immobilized tomato lectin interacts with high affinity with glycopeptides containing long poly-N-acetyllactosamine chains [1].
• A monoclonal rat IgM antibody (4C9) raised against F9 embryonal carcinoma cells reacted with fucosyl residues in poly-N-acetyllactosamine-type large carbohydrates of these cells (embryoglycan) [2].
• Long-chain sialo-oligosaccharides with poly-N-acetyllactosamine backbones (Ii antigen type) are major host cell receptors for the human pathogen Mycoplasma pneumoniae [3].
• In contrast to other cell lines analyzed, the neuroblastoma and pheochromocytoma lines contained predominantly glycopeptides completely cleavable with endo-beta-galactosidase, which indicated that they were linear-type poly-N-acetyllactosamine glycans [4].
• Poly-N-acetyllactosamine glycans of cellular glycoproteins: predominance of linear chains in mouse neuroblastoma and rat pheochromocytoma cell lines [4].

High impact information on N-acetyllactosamine

• Poly-N-acetyllactosamine structures are detected in the exudate cell glycoform only [5].
• Herein we describe the isolation and functional expression of a cDNA encoding beta-1,3-N-acetylglucosaminyltransferase (iGnT), an enzyme that is essential for the formation of poly-N-acetyllactosamine [6].
• Expression cloning of cDNA encoding a human beta-1,3-N-acetylglucosaminyltransferase that is essential for poly-N-acetyllactosamine synthesis [6].
• Ibeta6-N-acetylglucosaminyltransferase (IGnT) catalyzes the branching of poly-N-acetyllactosamine carbohydrate chains [7].
• The widely distributed hL-31 (CBP35, epsilon BP, mL-34, L-29, Mac-2) is a Ca(2+)-independent galactoside-binding lectin which functions as a receptor on mammalian cells for glycoproteins containing poly-N-acetyllactosamine side chains [8].

Chemical compound and disease context of N-acetyllactosamine

• The results suggest that the glycoprotein is a major carrier of poly-N-acetyllactosamine chains on differentiating teratocarcinoma F9 cells, and that its expression as revealed by the poly-N-acetyllactosamine labelling method is regulated by the stage of cellular differentiation [9].
• Roles of cell surface carbohydrates containing the 3-fucosyl-N-acetyllactosamine and poly-N-acetyllactosamine sequences (SSEA-1 and I antigens, respectively) in the compaction of mouse embryos have been investigated using the endo-beta-galactosidase of Bacteroides fragilis to modify the surface of cleavage-stage embryos [10].

Biological context of N-acetyllactosamine

• The expression of the presumed catalytic domain as a fusion protein with the IgG binding domain of protein A enabled us to demonstrate that the cDNA encodes iGnT, the enzyme responsible for the formation of GlcNAcbeta1 --> 3Galbeta1 --> 4GlcNAc --> R structure and poly-N-acetyllactosamine extension [6].
• Developmental patterning of carbohydrate antigens during early embryogenesis of the chick: expression of antigens of the poly-N-acetyllactosamine series [11].
• These results indicated that only certain glycosylation sites can be selectively modified by poly-N-acetyllactosamine, and those sites may confer the requirement by beta 1----3-N-acetylglucosaminyl transferase [12].
• N-linked glycans containing linear poly-N-acetyllactosamine as sorting signals in endocytosis in Trypanosoma brucei [13].
• The complete amino acid sequence of a poly-N-acetyllactosamine-binding pokeweed mitogen 4 (Pa-4) was determined using a protein sequencer [14].

Anatomical context of N-acetyllactosamine

• Binding of radiolabeled bacteria to blots of erythrocyte membrane proteins revealed binding to the poly-N-acetyllactosamine-containing components Band 3, Band 4.5, and polyglycosyl ceramides and to glycophorin A [15].
• These results also suggest that the time necessary for moving through the Golgi complex is a critical factor for poly-N-acetyllactosamine formation [16].
• Granulocytic differentiation of HL-60 cells is associated with increase of poly-N-acetyllactosamine in Asn-linked oligosaccharides attached to human lysosomal membrane glycoproteins [17].
• Surface radiolabeled effector cell membrane proteins were fractionated by tomato lectin-Sepharose 4B (poly-N-acetyllactosamine-specific) column chromatography [18].
• These data suggest that PSGL-1 from human neutrophils displays complex, sialylated, and fucosylated O-linked poly-N-acetyllactosamine that promote high affinity binding to P-selectin, but not to E-selectin [19].

Associations of N-acetyllactosamine with other chemical compounds

• The existence of poly-N-acetyllactosamine structures on T200 glycoprotein and the ability of lactosamine-type oligosaccharides to inhibit NK cell-mediated cytotoxicity suggest that these structures may also be important in NK-target binding [18].
• The aim of this work was to isolate and characterize carbohydrate binding proteins from NK cells that bind alphaGal or other potential xenoepitopes, such as N-acetyllactosamine (NAcLac), created by the deletion of alpha1,3galactosyltransferase (GT) in animals [20].
• Our studies demonstrate that L-14 binds with high affinity to oligosaccharides containing multiple repeating units (approximately 4) of the disaccharide [3Gal beta 1-4GlcNAc beta 1]n or poly-N-acetyllactosamine (PL) sequence [21].
• Branched poly-N-acetyllactosamine-type oligosaccharides were subjected to limited hydrolysis with 0.1% trifluoroacetic acid at 100 degrees C for 40 min and then separated on an amino-bonded silica column [22].
• This lectin is specific for beta 1-4-linked N-acetylglucosamine oligomers, such as the oligosaccharides of the poly-N-acetyllactosamine series that have been previously implicated in cell differentiation [23].

Gene context of N-acetyllactosamine

• We found that PSGL-1 had poly-N-acetyllactosamine, only some of which could be removed with endo-beta-galactosidase [19].
• Overexpression of GnT-V had no effect on the levels of cell surface expression of N-cadherin; however, it did cause a marked enhancement of both beta(1,6) branching and poly-N-acetyllactosamine expression on N-cadherin [24].
• A novel beta1,3-N-acetylglucosaminyltransferase (beta3Gn-T8), which synthesizes poly-N-acetyllactosamine, is dramatically upregulated in colon cancer [25].
• RNase 1 from healthy cells contained neutral complex biantennary structures, with smaller amounts of tri- and tetraantennary compounds, and glycans with poly-N-acetyllactosamine extensions, all extensively fucosylated [26].
• In this context, galectins are secreted to the extracellular milieu, where they recognize poly-N-acetyllactosamine chains on major ECM glycoproteins, such as fibronectin and laminin [27].

Analytical, diagnostic and therapeutic context of N-acetyllactosamine

• Proteins from the endocytic pathway in bloodstream forms of Trypanosome brucei are modified by the addition of linear poly-N-acetyllactosamine side chains, which permits their isolation by tomato lectin affinity chromatography [28].
• Matrix-assisted laser desorption ionization mass spectrometry and SDS-PAGE analysis identified several unique LOS glycoforms containing di-, tri-, and poly-N-acetyllactosamine repeats added to the terminal region of the main LOS branch synthesized by the heptosyltransferase III mutant [29].
• This review describes the poly-N-acetyllactosamine assembling machinery and focuses on recent advances in the molecular cloning and characterization of poly-N-acetyllactosamine synthase gene families [30].
• The thin-layer-chromatography immunostaining procedure was applied to human erythrocyte glycolipids using monoclonal anti-i and anti-I antibodies which are directed against epitopes on linear and branched carbohydrate chains of the neolacto (poly-N-acetyllactosamine) series [31].

References