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PubMed1983

Glycolipid-lectin interactions: detection by direct binding of 125I-lectins to thin layer chromatograms.

Glycolipids that bind 125I-labeled lectins are detected by autoradiography after thin layer chromatography of glycolipid standards or crude lipid extracts. Soybean agglutinin, Bandeiraea simplicifolia I isolectins A4 and B4, and Helix pomatia lectin are used to detect corresponding cell surface, glycolipid receptors in human and bovine erythrocytes. When lipid extracts from A and AB erythrocyte stroma are analyzed with Helix pomatia lectin, a polymorphic expression of blood group A glycolipid determinants is detected. The Bandeiraea simplicifolia isolectins react weakly with human erythrocyte glycolipids but bind at least 4 glycolipids in bovine stroma extracts. Soybean agglutinin reacts with glycolipids in all erythrocytes analyzed. This technique extends lectin specificity studies from inhibition analyses in aqueous systems using available, known structures to identification of specific, lectin-binding glycolipids in crude lipid extracts of cell membranes.

ABO Blood-Group System↗

PubMed1980

Studies on lectins. XLIX. The use of glycosyl derivatives of Dextran T-500 for affinity electrophoresis of lectins.

p-Aminophenyl glycosides and glycosylamines were coupled to periodate oxidized Dextran T-500 either directly or through an epsilon-aminocaproic acid spacer. The new glycosylated derivatives of dextran specifically precipitate lectins having the appropriate carbohydrate specificity, and thus were used in the preparation of affinity gels for affinity electrophoresis of lectins. The apparent strength of interaction of several lectins with carbohydrate residues immobilized in this way was less than with carbohydrates immobilized in O-glycosyl polyacrylamide copolymers. The presence of epsilon-aminocaproic spacer had no effect on the strength of interaction. The advantages of this type of macromolecular derivative of the ligand for affinity electrophoresis and some differences between the glycosylated dextrans and O-glycosyl polyacrylamide copolymers are discussed. Dextrans containing bound p-aminophenyl alpha-D-mannopyranoside and p-aminophenyl alpha-D-glucopyranoside were used to study the binding properties of concanavalin A and the lectin from Lathyrus sativus seeds. For the investigation of interaction of lectins from Ricinus communis and Glycine soja seeds, dextran derivatives containing bound p-aminophenyl alpha- and beta-D-galactopyranosides and alpha- and beta-D-galactopyranosylamines were used.

Binding Sites↗

PubMed1980

Lectins in the United States diet: a survey of lectins in commonly consumed foods and a review of the literature.

Plant lectins or phytohemagglutinins possess potent in vivo biological activities. Some, primarily of the family Leguminosae, have been shown to have deleterious nutritional effects. Little information exists, however, regarding the prevalence of lectins or the specific foods that contain lectins in the United States diet. In the present study the edible parts of 29 of 88 foods tested, including common salad ingredients, fresh fruits, roasted nuts, and processed cereals were found to possess significant lectin-like activity as assessed by hemagglutination and bacterial agglutination assays. Based on this survey and a review of the literature we conclude that dietary exposure to plant lectins is widespread. The spectrum of nutritional consequences of such exposure remains to be determined.

Agglutination Tests↗

PubMed1996

A lectin from leaves of Neoregelia flandria recognizes D-glucose, D-mannose and N-acetyl D-glucosamine, differing from the mannose-specific lectins of other monocotyledonous plants.

A mannose-specific lectin was isolated from leaves of Neoregelia flandria, an ornamental plant that belongs to Bromeliaceae, a family of monocotyledons. The amino acid composition and molecular mass of the lectin were similar to those of mannose-specific lectins from other monocotyledons. However, in a test to examine the inhibition of hemagglutination, it became apparent that the isolated lectin recognized D-glucose and N-acetyl D-glucosamine in addition to D-mannose, unlike mannose-specific lectins from the monocotyledons that have been reported to date.

Acetylglucosamine↗

PubMed2004

A new Ralstonia solanacearum high-affinity mannose-binding lectin RS-IIL structurally resembling the Pseudomonas aeruginosa fucose-specific lectin PA-IIL.

The plant pathogen Ralstonia solanacearum produces two lectins, each with different affinity to fucose. We described previously the properties and sequence of the first lectin, RSL (subunit M(r) 9.9 kDa), which is related to fungal lectins (Sudakevitz, D., Imberty, A., and Gilboa-Garber, N., 2002, J Biochem 132: 353-358). The present communication reports the discovery of the second one, RS-IIL (subunit M(r) 11.6 kDa), a tetrameric lectin, with high sequence similarity to the fucose-binding lectin PA-IIL of Pseudomonas aeruginosa. RS-IIL recognizes fucose but displays much higher affinity to mannose and fructose, which is opposite to the preference spectrum of PA-IIL. Determination of the crystal structure of RS-IIL complexed with a mannose derivative demonstrates a tetrameric structure very similar to the recently solved PA-IIL structure (Mitchell, E., et al., 2002, Nature Struct Biol 9: 918-921). Each monomer contains two close calcium cations that mediate the binding of the monosaccharide and explain the outstandingly high affinity to the monosaccharide ligand. The binding loop of the cations is fully conserved in RS-IIL and PA-IIL, whereas the preference for mannose versus fucose can be attributed to the change of a three-amino-acid sequence in the 'specificity loop'.

Adhesins, Bacterial↗

PubMed1987

The beta 1----2-D-xylose and alpha 1----3-L-fucose substituted N-linked oligosaccharides from Erythrina cristagalli lectin. Isolation, characterisation and comparison with other legume lectins.

The carbohydrate moieties of Erythrina cristagalli lectin were released as oligosaccharides by hydrazinolysis, followed by N-acetylation and reduction with NaB3H4. Fractionation of the tritium-labelled oligosaccharide mixture by Bio-Gel P-4 column chromatography and high-voltage borate electrophoresis revealed that it is composed of five neutral oligosaccharides. Structural studies by sequential exoglycosidase digestion in combination with methylation analysis and two-dimensional 1H-NMR showed that the major component was the fucose-containing heptasaccharide Man alpha 3(Man alpha 6)(Xyl beta 2)Man beta 4GlcNAc beta 4(Fuc alpha 3)GlcNAcol. This is the first report of such a structure in plant lectins. Small amounts of the corresponding afucosyl hexasaccharide were also identified, as well as three other minor components. The structure of the heptasaccharide shows the twin characteristics of a newly established family of N-linked glycans, found to date only in plants. The characteristics are substitution of the common pentasaccharide core [Man alpha 3(Man alpha 6)Man beta 4GlcNAc beta 4GlcNAc] by a D-xylose residue linked beta 1----2 to the beta-mannosyl residue and an L-fucose residue linked alpha 1----3 to the reducing terminal N-acetylglucosamine residue. The oligosaccharide heterogeneity pattern for Erythrina cristagalli lectin was also found for the lectins from four other Erythrina species and the lectins of two other legumes, Sophora japonica and Lonchocarpus capassa.

Carbohydrate Conformation↗

PubMed1992

The closely related homomeric and heterodimeric mannose-binding lectins from garlic are encoded by one-domain and two-domain lectin genes, respectively.

Lectin cDNA clones for two different lectins from garlic (Allium sativum L.) bulbs, ASAI and ASAII (ASA, Allium sativum agglutinin), were isolated and characterized. The first lectin, ASAI, is a heterodimer composed of two different subunits of 11.5 kDa and 12.5 kDa. It is translated from an mRNA of 1400 nucleotides encoding a polypeptide of 306 amino acids with two very similar domains. N-terminal sequencing of the two polypeptides of the mature lectin confirmed that both subunits are derived from the same precursor and that each corresponds to one of the two domains in the sequence. In contrast to ASAI, the second garlic lectin, ASAII, is a homodimer of two identical 12-kDa subunits. It is translated from an mRNA of approximately 800 nucleotides encoding a polypeptide of 154 amino acids. Interestingly, the coding region of the ASAII cDNA clones is almost identical to that of the second domain of the ASAI cDNA clones.

Amino Acid Sequence↗

PubMed1993

Lectin binding to chronic inflammatory gingival tissue: possible adhesion mechanisms based on lectin-carbohydrate interactions.

In this study, we analyzed the expression of different leukocyte surface antigens, of the adhesion molecules ELAM-1 and GMP-140 and binding of various lectins and neoglycoproteins in inflamed gingival tissue. Cell suspensions from collagenase-digested gingiva were analyzed by flow cytometry in a FACScan. The expression of ELAM-1, GMP-140, carbohydrate structures and lectins in gingival specimens was also studied by immunohistochemistry. Gingival tissue of patients with active periodontal disease contained between 5% and 50% CD45+ mononuclear cells, consisting mainly of CD19+ cells (B lymphocytes). CD62, resembling GMP-140, and ELAM-1 were strongly expressed on endothelial cells of these patients. Control subjects usually contained almost no CD45+ cells in their gingiva and no CD62+ or ELAM-1-positive endothelial cells could be found in 5 of 6 control persons. Analysis of the glycosylation pattern revealed staining of infiltrating cells by peanut agglutinin (PNA; specificity for galactose), whereas soy bean agglutinin (SBA; specificity for N-acetyl-galactosamine) bound to epithelial cells. An endogenous lactosyl-specific lectin could be detected on endothelial cells by binding of lactosyl-BSA. Ulex europeus I agglutinin (UEA-1, specific for fucose) showed selective staining of endothelial and epithelial cells. Expression of a fucose-binding lectin, demonstrated by binding of fucosylated BSA, could be found on infiltrating cells. The adhesion molecules ELAM-1 and GMP-140 seem to be involved in cell adhesion during chronic inflammation of the gingiva. Interaction of other carbohydrate residues with endogenous lectins might resemble additional adhesion mechanisms in inflamed gingiva.

Antigens, CD↗

PubMed2005

Characterization, occurrence, and molecular cloning of a lectin from Grifola frondosa: jacalin-related lectin of fungal origin.

A lectin named GFL was isolated from the fruiting body of the basidiomycete mushroom Grifola frondosa, which belongs to Aphyllophorales. The lectin had a molecular mass of 24 kDa on SDS-PAGE. The hemagglutinating activity of GFL was not inhibited by any monosaccharide, and inhibited only by porcine stomach mucin so far as tested. The occurrence of GFL was studied at three stages during fruiting body formation. The largest quantity of hemagglutinating activity was found in the fruiting body, and lesser amounts in the mycelial mat and the primordium. The 24-kDa band of GFL was found at all three stages, and the band-intensity corresponded to the level of activity in each sample. By cloning and sequencing the GFL-cDNA, the primary structure of this lectin was determined. GFL is composed of 181 amino acids, having no signal peptide. The amino acid sequence was found to be homologous to those of so-called jacalin-related plant lectins, suggesting that GFL is the first example of a jacalin-related lectin of fungal origin.

Amino Acid Sequence↗

PubMed2006

Lectin pathway of bony fish complement: identification of two homologs of the mannose-binding lectin associated with MASP2 in the common carp (Cyprinus carpio).

The lectin pathway of complement is considered to be the most ancient complement pathway as inferred from identification of ancient homologs of mannose-binding lectin (MBL) and MBL-associated serine proteases (MASPs) in some invertebrates. MBL homologs with galactose selectivity and an MASP3-like sequence also occur in bony fish, linking the evolution of the lectin complement pathway from invertebrates to higher vertebrates. However, these cannot be considered authentic complement components until confirmatory functional evidence is obtained. Here, we report the isolation and characterization of two MBL homologs from a cyprinid teleost, the common carp, Cyprinus carpio. One, designated GalBL, corresponds to the MBL-like molecule with the galactose specificity. The other is an authentic MBL with mannose specificity. Both were found to associate with a serine protease that cleaves native human C4 into C4b but not C4i with a hydrolyzed thioester. Molecular cloning and phylogenetic analysis revealed this C4-activating protease to be carp MASP2, indicating that MASP2 arose before the emergence of bony fish. Database mining of MBL-like genes reveals that MBL and GalBL genes are arranged in tandem in the zebrafish genome and that both lectins are conserved in the distantly related puffer fish. These results imply that bony fish have developed a diverged set of MBL homologs that function in the lectin complement pathway.

Animals↗

PubMed1991

Binding of lectins (Con-A, lens, helix, PHA) to binding sites induced in Tetrahymena by insulin and lectins.

Concanavalin-A (Con-A) gave rise to a moderate aggregation in untreated (control) Tetrahymena pyriformis GL populations. The cells pretreated (imprinted) with insulin or lectins underwent aggregation earlier and to a greater degree than the untreated control cells. Lens lectin, although of the same sugar specificity as Con-A, was considerably less active than the latter. Helix lectin and phytohaemagglutinin (PHA), although of similar sugar specificity, accounted for a dissimilar extent of cell aggregation, in that Helix lectin was comparable in activity to Con-A. Pretreatment (imprinting) with insulin enhanced the aggregation inducing effect of those lectins which were capable of overlapping on the insulin receptor owing to similar specificity.

Animals↗

PubMed1978

Studies on lectins. XXXVII. Isolation and characterization of the lectin from Jimson-weed seeds (Datura stramonium L.).

The lectin of Jimson-weed seeds (Datura stramonium L.) was isolated by affinity chromatography on a polysaccharide mixture from mycelium of Aspergillus niger. The lectin yields two bands on disc electrophoresis, it has sedimentation coefficient s20,w = 3.8 S and its apparent molecular weight estimated by thin layer gel chromatography is 120,000. The lectin reduced with mercaptoethanol yields on polyacrylamide gel electrophoresis in the presence of dodecyl sulfate three zones corresponding to subunits of molecular weight 72,000, 45,000 and 25,000. The lectin contains large amounts of cystine, glycine, 6.3% of hydroxyproline residues, 4.5% glucosamine and 28% of neutral sugar, predominantly arabinose. The lectin is nonspecific in human erythrocyte ABO system, it is not inhibited by simple sugars but is inhibited by a partial hydrolysate of chitin-containing mixture of polysaccharides from Aspergillus niger.

Amino Acids↗

PubMed1984

Lectin receptors as markers of lymphoid cells. II. Reed-Sternberg cells share lectin-binding properties of monocyte macrophages.

The origin of the Reed-Sternberg cells of Hodgkin's disease is controversial with proponents of transformed lymphocyte and macrophage histiocyte derivations. Lectin receptors are potentially useful new cell markers in the investigation of lymphoproliferative disease. In this study, the lectin-binding properties of the Reed-Sternberg cell were investigated in an effort to clarify the cell of origin. Utilizing a simple peroxidase technique applicable to formalin-fixed, paraffin-embedded tissue, lectin binding was studied in 13 cases of Hodgkin's disease. Reed-Sternberg cells were found to bind cytoplasmic concanavalin A, but not Arachis hypogaea (peanut agglutinin) or Lotus tetragonolobus (asparagus pea). These are the lectin-binding properties of macrophage histiocytes rather than transformed lymphocytes. Lectin-binding studies support the macrophage origin of the neoplastic cells of Hodgkin's disease.

Adolescent↗

PubMed2000

Entamoeba histolytica: deletion of the GPI anchor signal sequence on the Gal/GalNAc lectin light subunit prevents its assembly into the lectin heterodimer.

Adherence and cytotoxicity of Entamoeba histolytica require the function of a heterodimeric galactose and N-acetylgalactosamine (Gal/GalNAc)-specific lectin. The lectin heavy subunit (Hgl) contains a carbohydrate recognition domain and mediates inside-out cell signaling via its cytoplasmic tail. The function of the lectin light subunit (Lgl) is unknown. The lectin has a unique mechanism of membrane association: Hgl is transmembrane but Lgl is glycosylphosphatidylinositol (GPI) anchored. The role of the GPI anchor signal sequence in heterodimer assembly was tested. Epitope-tagged Lgl with or without the GPI anchor addition signal was expressed in E. histolytica trophozoites. Tagged Lgl did not assemble with Hgl into a lectin heterodimer in the absence of the GPI addition signal. Consistent with previous results that only the Hgl subunit mediates adherence, the monomeric Lgl without the GPI anchor signal lacked Gal/GalNAc-binding activity.

Animals↗

PubMed1993

Use of Phaseolus vulgaris leukoagglutinating lectin in histochemical and blotting techniques: a comparison of digoxigenin- and biotin-labelled lectins.

An increase in the number of beta 1,6 branches of the trimannosyl core of asparagine-linked oligosaccharides has been shown to be directly correlated with the metastatic potential of cultured tumour cells. The Phaseolus vulgaris leukoagglutinating lectin (PHA-L) binds to beta 1,6 branches of tri- and tetra-antennary oligosaccharides. We have applied digoxigenin- and biotin-conjugated PHA-L to establish a non-radioactive detection system for beta 1,6 branches, which can be used in lectin blotting as well as light and electron microscopic cytochemistry. For this purpose the HCT116 human colon carcinoma cell line and colon carcinoma tissue were investigated. Digoxigenin-conjugated PHA-L in conjunction with alkaline phosphatase-conjugated anti-digoxigenin antibodies was superior to biotin-conjugated PHA-L in lectin blotting with respect to sensitivity and specificity. Similarly, the digoxigenin conjugated PHA-L in conjunction with gold-labelled anti-digoxigenin antibodies resulted in more intense specific staining and lower background compared to biotin-conjugated PHA-L visualized with a streptavidin immunogold complex. The specificity of lectin binding in blotting and cytochemical studies was demonstrated by the absence of staining when the lectin was omitted or preabsorbed with glycoprotein, and following pretreatment of the cellular homogenates or tissue sections by N-glycosidase F. Our results demonstrate that digoxigenin-conjugated PHA-L provides high sensitivity and specificity for histochemical and blotting techniques and is amenable for quantification. The technique should have applications in tumour research.

Biotin↗

PubMed1987

A new method of lectin histochemistry for the study of brain angiogenesis. Lectin angiography.

In an attempt to analyse the kinetics of angiogenesis in the brain, we developed a new lectin-histochemical staining technique for identifying the vasculature. Three horseradish-peroxidase-conjugated lectins, i.e., Griffonia simplicifolia agglutinin 1 (GS1), Ricinus communis agglutinin 1 (RCA1) and soybean agglutinin (SBA), selectively stained vascular walls in brain-tissue sections. When these lectins were injected into the circulation of ether-anesthetized animals via the pulsating left ventricle, they bound specifically to the inner surface of endothelial cells and revealed the three-dimensional architecture of the vascular network within thick tissue preparations. When this technique, referred to a lectin angiography, was combined with 5-bromo-2-deoxyuridine (BudR) immunohistochemistry, proliferating capillary cells could be easily identified in three-dimensional structures of the developing vasculature. Because of its simplicity and wide applicability, lectin angiography should be useful for analysing the kinetics of angiogenesis in developmental, regenerative, and pathological conditions in various tissues and organs.

Aging↗

PubMed1983

Studies on lectins of amago (Oncorhyncus rhodurus). I. Amago ova lectin and its receptor on homologous macrophages.

A lectin was found in the ova of amago, a Japanese trout (Oncorhyncus rhodurus), which agglutinates rabbit, rat and human B-type erythrocytes. The hemagglutination was specifically inhibited by monosaccharides, L-rhamnose, D-galactose, and their C2 and C4 analogs, and p-nitrophenyl-alpha-D-galactoside and melibiose, indicating a binding specificity for alpha-L-rhamnosyl or alpha-D-galactosyl type sugar moiety. To study its interaction with homologous cells, amago peritoneal macrophages were isolated from corn starch-stimulated peritoneal exudates. The lectin-rabbit erythrocyte complexes were found to adhere onto the macrophages harvested on the 4th day or later after the stimulation, but not to those obtained within 3 days; the latter macrophages acquired the complex-binding capacity when cultured for 3 to 4 days in vitro. These findings indicated that a lectin receptor is expressed on peritoneal macrophages after inflammatory stimulation. Similar lectin receptor-bearing macrophage-like-cells were also detected during in vitro amago head kidney culture. This suggested that the inflammatory induced peritoneal macrophages may be differentiated from the head kidney macrophage precursor cells and during this process the ova lectin receptors also become expressed.

Animals↗

PubMed1977

Studies on lectins. XXXII. Application of affinity electrophoresis to the study of the interaction of lectins and their derivatives with sugars.

Affinity electrophoresis was used to study the sugar binding heterogeneity of lectins or their derivatives. Commercial and demetallized preparations of concanavalin A could be resolved by affinity electrophoresis into three components with different affinity to immobilized sugar. Similarly the Vicia cracca lectin obtained by affinity chromatography behaved on affinity gels as a mixture of active and inactive molecular species. Affinity electrophoresis has shown that the nonhemagglutinating acetylated lentil lectin and photo-oxidized or sulfenylated pea lectin retain their sugar binding properties; dissociation constants of saccharide complexes of these derivatives are similar to those of native lectins. The presence of specific immobilized sugar in the affinity gel improved the resolution of isolectins from Dolichos biflorus and Ricinus communis seeds.

Acetylation↗