Highly efficient synthesis of alternate alpha- and beta-(1-->3)-linked glucose hepta- and octasaccharides

Two heptasaccharides alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-beta-D-Glcp-1-OMP and beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp1-OMP, and two octasaccharides alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-1-OMP and beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-beta-D-Glcp1-OMP were synthesized in a stereospecific way by remote control.     

Isolation and comparative analysis of multiple isoenzymes of glutathione-S-transferase from the liver of intact rats and rats administered phenobarbital, 3-methylcholanthrene and butylhydroxytoluene

Seven glutathione-S-transferase (GST) isozymes were purified from liver cytosol of intact male Wistar rats: 1-1(A), 1-1(B), 1-2, 2-2, 3-3, 3-4, 4-4. Treatment of rats with butylated hydroxytoluene (BHT) led to the induction of isozymes GST 1-1(A), 1-1(B) (2-fold), 3-3 (3.5-fold) as well as to the appearance of two new isozymes--1-3 and 4-4(A). Phenobarbital (PB) induced isozymes GST 1-1(A), 1-1(B) (2-fold) and 3-3 (1.5-fold). BHT and PB caused an increase in the specific activity of isozymes 1-1(A), 1-1(B), 3-3, 3-4 towards 1-chloro-2.4-dinitrobenzene and 1.2-dichloro-4-nitrobenzene. 3-Methylcholanthrene (MC) induced isozymes 1-2 (1.5-fold), 2-2 (2-fold) and 4-4 (3-fold). A conclusion was drawn that BHT and PB induced the GST subunits 1 and 3, whereas MC--subunits 2 and 4.     

Cutting Edge: Allele-specific and peptide-dependent interactions between KIR3DL1 and HLA-A and HLA-B

Although it is clear that KIR3DL1 recognizes Bw4(+) HLA-B, the role of Bw4(+) HLA-A allotypes as KIR3DL1 ligands is controversial. We therefore examined the binding of tetrameric HLA-A and -B complexes, including HLA*2402, a common Bw4(+) HLA-A allotype, to KIR3DL1*001, *005, *007, and *1502 allotypes. Only Bw4(+) tetramers bound KIR3DL1. Three of four HLA-A*2402 tetramers bound one or more KIR3DL1 allotypes and all four KIR3DL1 allotypes bound to one or more HLA-A*2402 tetramers, but with different binding specificities. Only KIR3DL1*005 bound both HLA-A*2402 and HLA-B*5703 tetramers. HLA-A*2402-expressing target cells were resistant to lysis by NK cells expressing KIR3DL1*001 or *005. This study shows that HLA-A*2402 is a ligand for KIR3DL1 and demonstrates how the binding of KIR3DL1 to Bw4(+) ligands depends upon the bound peptide as well as HLA and KIR3DL1 polymorphism.     

Androgen and progesterone metabolism in the central and peripheral nervous system

This paper summarizes the most recent data obtained in the authors' laboratory on the metabolism of testosterone and progesterone in neurons, in the glia, and in neuroblastoma cells. The activities of the 5α-reductase (the enzyme that converts testosterone into dihydrotestosterone, DHT), and of the 3α-hydroxysteroid dehydrogenase (the enzyme that converts DHT into 5α-androstane-3α,17β-diol, 3α-diol) have been first evaluated in primary cultures of neurons, oligodendrocytes and type-1 and -2 astrocytes, obtained from the fetal or neonatal rat brain. All the cultures were used on the fifth day. The formation of DHT or 3α-diol was evaluated incubating the different cultures with labeled testosterone or DHT as substrates. The results obtained indicate that the formation of DHT takes place preferentially in neurons; however, type-2 astrocytes and oligodendrocytes also possess considerable 5α-reductase activity, while type-1 astrocytes show a much lower enzymatic concentration. A completely different localization was observed for 3α-hydroxysteroid dehydrogenase; the formation of 3α-diol appears to be prevalently, if not exclusively, present in type-1 astrocytes; 3α-diol is formed in very low yields by neurons, type-2 astrocytes and oligodendrocytes. The compartmentalization of two strictly correlated enzymes (5α-reductase and 3α-hydroxysteroid dehydrogenase) in separate central nervous system (CNS) cell populations suggests the simultaneous participation of neurons and glial cells in the 5α-reductive metabolism of testosterone. Subsequently it has been shown that, similarly to what happens when testosterone is used as the substrate, the 5α-reductase which metabolizes progesterone into 5α-pregnane-3,20-dione (DHP) shows a significantly higher activity in neurons than in glial cells; however, type-1 and -2 astrocytes as well as oligodendrocytes also possess some ability to 5α-reduce progesterone. On the other hand, 3α-hydroxysteroid dehydrogenase, the enzyme which converts DHP into 5α-pregnane-3α-ol-20-one, appears to be present mainly in type-1 astrocytes; much lower levels of this enzyme are present in neurons and in type-2 astrocytes. At variance with the previous results obtained using androgens as precursors, oligodendrocytes show considerable 3α-hydroxysteroid dehydrogenase activity, even if this is statistically lower than that present in type-1 astrocytes. The existence of isoforms of the enzyme involved in androgen and progesterone metabolism is discussed.Finally, the ability of the human neuroblastoma cell line SH-SY5Y to metabolize androgens and progesterone was studied incubating the cells in the presence of labeled testosterone or progesterone to measure, respectively, the formation of DHT or DHP (5α-reductase activity). 3α-Hydroxysteroid dehydrogenase activity was studied by evaluating the conversion of labeled DHT into 3α-diol. The results demonstrate that undifferentiated neuroblastoma cells possess a significant 5α-reductase activity, as shown by the considerable conversion of testosterone into DHT; moreover, this enzymatic activity seems to be significantly stimulated following cell differentiation induced by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), but not after differentiation induced by retinoic acid (RA). The 5α-reductase present in SH-SY5Y cells is also able to convert progesterone into DHP. In undifferentiated cell, this conversion is about 8 times higher than that of testosterone into DHT. Under the influences of TPA and RA, the formation of DHP follows the same pattern observed for that of DHT. SH-SY5Y cells also appear to possess the enzyme 3α-hydroxysteroid dehydrogenase, since they are able to convert DHT into 3α-diol. This enzymatic activity is not altered following TPA-induced differentiation, and appears to be decreased following treatment with RA. It is suggested that the SH-SY5Y cell line may represent a useful “in vitro” model for the study of the mechanisms involved in the control of androgen and progesterone metabolism in nervous cells.     

Isolation and characterization of gangliosides from Trypanosoma brucei

Gangliosides were isolated from Trypanosoma brucei and analyzed by thin-layer chromatography (TLC) and TLC immunostaining test. Four species of gangliosides, designated as G-1, G-2, G-3, and G-4, were separated by TLC. G-1 ganglioside had the same TLC migration rate as GM3. In contrast, G-2, G-3, and G-4 gangliosides migrated a little slower than GM1, GD1a, and GD1b, respectively. To characterize the molecular species of gangliosides from T. brucei, G-1, G-2, G-3, and G-4 gangliosides were purified and analyzed by TLC immunostaining test with monoclonal antibodies against gangliosides. G-1 ganglioside showed the reactivity to the monoclonal antibody against ganglioside GM3. G-2 was recognized by the anti-GM1 monoclonal antibody. G-3 showed reaction with the monoclonal antibody to GD1a. G-4 had the reactivity to anti-GD1b monoclonal antibody. Using 4 kinds of monoclonal antibodies, we also studied the expression of GM3, GM1, GD1a, and GD1b in T. brucei parasites. GM3, GM1, GD1a, and GD1b were detected on the cell surface of T. brucei. These results suggest that G-1, G-2, G-3, and G-4 gangliosides are GM3 (NeuAc alpha2-3Gal beta1-4Glc beta1-1Cer), GM1 (Gal beta1-3GalNAc beta1-4[NeuAc alpha2-3]Gal beta1-4Glc beta1-1Cer), GD1a (NeuAc alpha2-3Gal beta1-3GalNAc beta1-4[NeuAc alpha2-3]Gal beta1-4Glc beta1-1Cer), and GD1b (Gal beta1-3GalNAc beta1-4[NeuAc alpha2-8NeuAc alpha2-3]Gal beta1-4Glc beta1-1Cer), respectively, and also that they are expressed on the cell surface of T. brucei.     

Preparation and configuration of racemic and optically active analgesic dialkylaminoalkylnaphthalenes

The alkylaminoalkylnaphthalene 3 shows interesting opioid-like analgesic properties, μ-selective ligand competition, and enkephalin hydrolyzing enzyme inhibition. 3 possesses two chiral centers and can exist as two racemic pairs and four diastereomers. Since the binding of opioids with the receptor is stereoselective, it was important to have the two racemic pairs as well as the four diastereomers. In this paper the synthesis of the (1R,2R/1S,2S)- and (1R,2S/1S,2R)-racemates and the (1R,2R)- and (1S,2S)-enantiomers of the 1-ethyl-1-hydroxy-1-[2-(6-hydroxynaphthyl)]-2-methyl-3-dimethylaminopropane 3 is considered and the determination of absolute configuration is described. The (1R,2R/1S,2S)- 3 and (1R,2S/1S,2R)- 3 racemates and the (1R,2R)- 3 and (1S,2S)- 3 enantiomers were prepared by reaction of the racemic and optically active 1-dimethylamino-2-methylpentan-3-one 2 , respectively, with the lithiation product obtained from 2-bromo-6-tetrahydropyranyloxynaphthalene and acidic hydrolysis. The optical resolution of aminoketone 2 was carried out via fractional crystallization of salts (+)- and (?)-dibenzoyltartrates. The configuration of the optically active compounds was determined by X-ray analysis of a crystal of (+)-(1R,2R)- 3 · HCl · H₂O. Preliminary pharmachological tests showed that (+)-(1R,2R)- 3 enantiomer is able to induce opioid-like analgesia with a relative potency 2.5 times that of (1R,2R/1S,2S)- 3 and about 4 times that of morphine. © 1994 Wiley-Liss, Inc.     

Isolation and characterization of monoacetyldiglycerides from bovine udder

Monoacetyldiglycerides (MADGs) were isolated from an animal tissue, bovine udder, by solvent extraction and silica gel column chromatography. Monoacetyldiglyceride structures were identified using a variety of 1-D and 2-D NMR techniques and collision-induced dissociation (CID) tandem mass spectrometry coupled with fast atom bombardment. CID of sodium-adducted molecular ions ([M+ Na](+)) generated numerous types of product ions providing information on the double bond position of fatty acyl groups as well as fatty acid compositions. Structural analysis led to the classification of the MADGs isolated from bovine udder as 1-palmitoyl-2-lauroyl-3-acetyl-rac-glycerol, 1, 2-dimyristoyl-3-acetyl-rac-glycerol, 1-palmitoyl-2-myristoyl-3-acetyl-rac-glycerol, 1-oleoyl-2-myristoyl-3-acetyl-rac-glycerol, 1-palmitoyl-2-palmitoleoyl-3-acetyl-rac-glycerol, 1, 2-dipalmitoyl-3-acetyl-rac-glycerol, 1-linoleoyl-2-palmitoyl-3-acetyl-rac-glycerol, 1-oleoyl-2-palmitoleoyl-3-acetyl-rac-glycerol, 1-oleoyl-2-palmitoyl-3-acetyl-rac-glycerol, 1-stearoyl-2-palmitoyl-3-acetyl-rac-glycerol, 1-oleoyl-2-linoleoyl-3-acetyl-rac-glycerol, 1, 2-dioleoyl-3-acetyl-rac-glycerol, and 1-stearoyl-2-oleoyl-3-acetyl-rac-glycerol.     

Efficient production and characterization of Bacillus anthracis lethal factor and a novel inactive mutant rLFm-Y236F

The receptor binding to interleukin (IL)-13 is composed of the IL-13 receptor α1 chain (IL-13Rα1) and the IL-4 receptor α chain (IL-4Rα). In order to investigate the interaction of IL-13 with IL-13Rα1 and IL-4Rα, the DNA fragments coding the extracellular regions of human IL-13Rα1 and the IL-4Rα (containing a cytokine receptor homologous region) were fused with mouse Fc and expressed by a silkworm–baculovirus system. The expressed receptors were successfully purified by affinity chromatography using protein A, and the Fc region was removed by thrombin digestion. After further purification with anion-exchange chromatography, these receptors were used to investigate the ligand–receptor interaction. Size exclusion chromatography and SPR analysis revealed that mixture of IL-13 and IL-13Rα1 showed predominant affinity to IL-4Rα, although neither detectable affinity of IL-13 nor IL-13Rα1 was observed against IL-4Rα. Combining these data with the moderate affinity of IL-13 to IL-13Rα1, this indicates that IL-13 first binds to IL-13Rα1 and recruits consequently to IL-4R.     

Assignment of the1H- and13C-NMR spectra of eight oligosaccharides of the lacto-N-tetraose and neotetraose series

The assignment of the 13C- and 1H-NMR spectra of eight oligosaccharides of the lacto-N-tetraose and neotetraose series was obtained from homonuclear and heteronuclear correlation spectroscopy. These analyses were performed on the following compounds: 1. Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc; 2. NeuAc alpha 2-3Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc; 3. Gal beta 1-3[NeuAc alpha 2-6]GlcNAc beta 1-3Gal beta 1-4Glc; 4. NeuAc alpha 2-3Gal beta 1-3[NeuAc alpha 2-6]GlcNAc beta 1-3Gal beta 1-4Glc; 5. NeuAc alpha 2-3Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta 1-3Gal beta 1-4Glc; 6. Fuc alpha 1-2Gal beta 1-3[NeuAc alpha 2-6]GlcNAc beta 1-3Gal beta 1-4Glc; 7. Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc; 8. NeuAc alpha 2-6Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc.     

Repair of 3-methylthymine and 1-methylguanine lesions by bacterial and human AlkB proteins

The Escherichia coli AlkB protein repairs 1-methyladenine (1-meA) and 3-methylcytosine (3-meC) lesions in DNA and RNA by oxidative demethylation, a reaction requiring ferrous iron and 2-oxoglutarate as cofactor and co-substrate, respectively. Here, we have studied the activity of AlkB proteins on 3-methylthymine (3-meT) and 1-methylguanine (1-meG), two minor lesions which are structurally analogous to 1-meA and 3-meC. AlkB as well as the human AlkB homologues, hABH2 and hABH3, were all able to demethylate 3-meT in a DNA oligonucleotide containing a single 3-meT residue. Also, 1-meG lesions introduced by chemical methylation of tRNA were efficiently removed by AlkB. Unlike 1-meA and 3-meC, nucleosides or bases corresponding to 1-meG or 3-meT did not stimulate the uncoupled, AlkB-mediated decarboxylation of 2-oxoglutarate. Our data show that 3-meT and 1-meG are repaired by AlkB, but indicate that the recognition of these substrates is different from that in the case of 1-meA and 3-meC.     

SATB1 3′-UTR and lncRNA-UCA1 competitively bind to miR-495-3p and together regulate the proliferation and invasion of gastric cancer

High expression of special AT-rich-binding protein 1 (SATB1) correlates with the advanced TNM stage and short overall and recurrence-free survival of gastric cancer (GC). A bioinformatic analysis revealed that SATB1 3′-untranslated region (3′-UTR) and long noncoding RNA UCA1 (lncRNA-UCA1) might competitively bind to microRNA-495-3p (miR-495-3p). Interestingly, lncRNA-UCA1 is also an important contributor to GC. The current study aimed to demonstrate the potential interaction among SATB1/miR-495-3p/lncRNA-UCA1 network and their effects on GC proliferation and invasion. The expression in GC and paracancerous normal tissues were assessed using real-time polymerase chain reaction and Western blot analysis. Luciferase reporter, RNA pull-down, and transfection assays were performed to determine the interaction among SATB1/miR-495-3p/lncRNA-UCA1 network in GC cells. GC proliferation and invasion were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, transwell invasion, and colony formation assays. Results showed higher expression of SATB1 and lncRNA-UCA1 but lower miR-495-3p expression in GC than in the normal tissues. In luciferase reporter assay, miR-495-3p bound to three seed sequences in SATB1 3′-UTR but only one in lncRNA-UCA1. SATB1 knockdown increased the combination of miR-495-3p with lncRNA-UCA1 but decreased lncRNA-UCA1 expression. Decreased lncRNA-UCA1 was also observed with the mimics increased miR-495-3p. These data suggested that SATB1 3′-UTR functions as a competing endogenous RNA of miR-495-3p and positively regulates lncRNA-UCA1. LncRNA-UCA1 knockdown only decreased SATB1 expression in MKN-45 cells but not in BGC-823 cells, which suggested that the regulatory effect of lncRNA-UCA1 on SATB1 by sponging miR-495-3p is cell-dependent. This study further identified that SATB1/miR-495-3p/lncRNA-UCA1 network is implicated in GC proliferation and invasion. The current study firstly revealed that SATB1 interacts with miR-495-3p/lncRNA-UCA1 network, whereby enhancing GC proliferation and invasion.     

Direct and biochemical interaction between dopamine D3 receptor and elongation factor-1Bbetagamma

Novel signaling components of dopamine D3 receptor (D3R) were searched using yeast two-hybrid system, and the gamma subunit of elongation Factor-1B (eEF1Bgamma) was found to interact with D3R. This interaction was observed specifically between eEF1Bgamma and D3R but not with D2R or D4R. Immunocytochemical studies showed that D3R and eEF1Bgamma form clusters on the plasma membrane and their co-localization was evident in these clusters. The beta subunit of eEF1B (eEF1Bbeta), which forms a tight complex with eEF1Bgamma, was phosphorylated on serine residues in response to the stimulation of D3R. Phosphorylation of eEF1Bbeta was insensitive to pertussis toxin or wortmannin, however, stimulation of cellular protein kinase C (PKC) directly phosphorylated eEF1Bbeta and depletion of PKC abolished D3R-mediated phosphorylation of eEF1Bbeta. These results suggest the involvement of PKC, but not Gi/o proteins or phosphatidylinositol 3-kinase, in D3R-mediated phosphorylation of eEF1Bbeta. Stimulation of D3R did not activate PKC, but the activation of PKC resulted in the phosphorylation of D3R. These results show that PKC has a permissive role for the D3R-mediated phosphorylation of eEF1Bbeta, and suggest that PKC could modulate the mutual interaction between two protein by phosphorylating both D3R and eEF1Bbeta. Therefore, the cellular PKC level would be important for the D3R-mediated modulation of eEF1B, and for their cellular regulations such as protein synthesis or cellular proliferation.     

Isolation and structural studies of phosphate-containing oligosaccharides from alkaline and acid hydrolysates of Streptococcus pneumoniae type 6B capsular polysaccharide

The capsular polysaccharide of Streptococcus pneumoniae serotype 6B [----2)-alpha-D-Galp-(1----3)-alpha-D-Glcp-(1----3)-alpha-L-Rhap-( 1----4)- D-RibOH-(5-P----]n was depolymerised under alkaline (NaOH) and acidic (HF) conditions. The former treatment yielded, as the major component, alpha-2-P-Galp-(1----3)-alpha-Glcp-(1----3)-alpha-Rhap-(1----4)-5- P-RibOH. The latter treatment at -16 degrees gave alpha-Galp-(1----3)-alpha-Glcp-(1----3)-alpha-Rhap-(1----4)-Rib OH-(5-P----2)- alpha-Galp-(1----3)-alpha-Glcp-(1----3)-alpha-Rhap-(1----4)-Rib OH and at 4 degrees gave alpha-Galp-(1----3)-alpha-Glcp-(1----3)-alpha-Rhap-(1----4)-Rib OH. These oligosaccharides were characterised by sugar analysis, f.a.b.-m.s., and 1H- and 13C-n.m.r. spectroscopy.     

Primary structure of four human milk octa-, nona-, and undeca-saccharides established by 1H- and 13C-nuclear magnetic resonance spectroscopy.

The structures of two octasaccharides, one nonasaccharide, and one undecasaccharide, isolated from human milk, have been investigated by 1H- and 13C-nuclear magnetic resonance spectroscopy. The structures of these oligosaccharides are: beta-D-Galp-(1----4)-[alpha-L-Fucp- (1----3)]-beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4)-[alpha-L-Fucp+ ++- (1----3)]-beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4)-D-Glc; beta-D-GALp-(1----3)-[alpha-L-Fucp-(1----4)]-beta-D-GlcpNAc-(1---- 3)-beta-D - Galp-(1----4)-[alpha-L-Fucp-(1----3)]-beta-D-GlcpNAc-(1----3)-beta -D-Galp- (1----4)-D-Glc; beta-D-Galp-(1----4)-[alpha-L-Fucp-(1----3)]-beta-D-GlcpNAc-(1---- 6)-(alpha - L-Fucp-(1----2)-beta-D-Gal-(1----3)-[alpha-L-Fucp-(1----4)]- beta-D-GlcpNAc- (1----3))-beta-D-Galp-(1----4)-D-Glc; and alpha-L-Fucp-(1----2)-beta-D-Galp-(1----3)-beta-D-GlcpNAc-(1----3) -beta-D- Galp-(1----4)-[alpha-L-Fucp-(1----3)]-beta-D-GlcpNAc-(1----6)-[alp ha-L- Fucp-(1----2)-beta-D-Galp-(1----3)-beta-D-GlcpNAc-(1----3)]-beta-D -Galp- (1----4)-D-Glc. The two octasaccharides have been previously isolated from human milk as a mixture, and in a pure form from new-born feces, but the n.m.r. data were not provided. These two octasaccharides display the di-Lewis X and the composite Lewis A-Lewis X antigenic determinant, previously described as neo-antigens of adenocarcinoma cell lines.     

Concanavalin A binding and endoglycosidase D resistance of beta1,2-xylosylated and alpha 1,3-fucosylated plant and insect oligosaccharides

The binding to concanavalin A (Con A) by pyridylaminated oligosaccharides derived from bromelain (Man alpha 1,6(Xyl beta 1, 2) Man beta 1, 4GlcNAc beta 1, 4(Fuc alpha 1, 3)GlcNAc), horseradish peroxidase (Man alpha 1,6(Man alpha 1, 3) (Xyl beta 1, 2)Man beta 1, 4GlcNAc beta 1,4(Fuc alpha 1, 3) GlcNAc), bee venom phospholipase A2 (Man alpha 1,6Man beta 1,4GlcNAc beta 1,4GlcNAc and Man alpha 1,6(Man alpha 1, 3)Man beta 1,4GlcNAc beta 1, 4 (Fuc alpha 1, 3)GlcNAc) and zucchini ascorbate oxidase (Man alpha 1,6(Man alpha 1, 3) (Xyl beta 1, 2)Man beta 1, 4 GlcNAc beta 1, 4GlcNAc) was compared to the binding by Man3GlcNAc2, Man5GlcNAc2 and the asialo-triantennary complex oligosaccharide from bovine fetuin. While the fetuin oligosaccharide did not bind, bromelain, zucchini, Man2GlcNAc2 and horseradish peroxidase were retarded (in that order). The alpha 1, 3-fucosylated phospholipase, Man3GlcNAc2 and Man5GlcNAc2 structures were eluted with 15 M alpha -methylmannoside. It is concluded that core alpha 1,3-fucosylation has little or no effect on ConA binding while xylosylation decreases affinity for ConA. In a parallel study comparing the endoglycosidase D (Endo D) sensitivities of Man3GlcNAc2, IgG-derived GlcNAc beta 1, 2Man alpha 1,6(GlcNAc beta 1,2Man alpha 1,3)Man beta 1,4GlcNAc beta 1,4(Fuc alpha 1,6)GlcNAc, the phospholipase Man alpha 1,6(Man alpha 1, 3)Man beta 1, 4GlcNAc beta 1,4(Fuc alpha 1,3)GlcNAc, and horseradish and zucchini pyridylaminated N-linked oligosaccharides, it was found that only the Man3GlcNAc2 structure was cleaved. The IgG structure was sensitive only when beta -hexosaminidase was also present. Thus, in contrast to core alpha 1,6-fucosylated structures, such as those present in mammals, the presence of core alpha 1,3-fucose, as found in structures from plants and insects, and/or beta 1,2-xylose, as found in plants, causes resistance to Endo D.