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Soybean lectin and related proteins in seeds and roots of le and le soybean varieties.

The localizations of soybean lectin (SBL) and antigenically related proteins in cotyledons and roots of lectin positive (Le(+)) and lectin negative (Le(-)) soybean cultivars were compared by light level immunocytochemistry using antibodies produced against the 120 kilodalton (kD) native seed lectin tetramer or its subunits. Lectin is present in the protein bodies of cotyledons cells as are two other seed proteins, the Kunitz trypsin inhibitor and the storage protein glycinin. Analysis of single seed extracts by immunoblotting of sodium dodecyl sulfate-polyacrylamide gels using the same antibodies, reveals up to 4 milligrams of the 30 kD seed lectin protein is present per seed in the Le(+) varieties. There is no detectable lectin in the protein bodies of Le(-) cotyledons as determined by immunocytochemistry and immunoblotting. Enzyme-linked immunosorbent assay confirmed this result to a sensitivity of less than 20 nanograms per seed. In contrast, the roots of both Le(+) and Le(-) plants bind the seed lectin antibody during immunocytochemistry, with fluorescence mainly localized in vacuole-like bodies in the epidermis. Root extracts contain a 33 kD polypeptide that binds anti-SBL antibody at an estimated minimal level of 20 nanograms per 4-day seedling, or 2.0 nanograms per primary root tip. This polypeptide is also present in the embryo axis and in leaves. The latter also contain a 26 kD species that binds seed lectin antibody. The 30 kD seed lectin subunit, however, is not detectable in roots or leaves.

Journal Article↗

Studies on the endogenous galactose-binding lectin during early development of the embryo of Xenopus laevis.

Embryos of the frog Xenopus laevis at cleavage, blastula, gastrula and neurula stages contain a galactose-specific lectin. Extracts of gastrula embryos show the highest specific activity for this lectin compared to the other stages. Haemagglutinating activity of crude extracts is inhibited by lactose, alpha-galactose, beta-galactose, alpha Gal(1----4) beta Gal, beta Gal(1----3) alpha GalNAc, beta Gal(1----3) beta GlcNAc, beta Gal (1----4) beta GlcNAc, and most effectively by the disaccharide alpha Gal(1----3) beta Gal. Lectin from all stages was purified by absorption to galactose-linked immunoadsorbent or by affinity chromatography on a column of p-aminophenyl-beta-D-lactoside coupled to Sepharose 4B. In order to identify a single lectin band under reducing conditions in sodium dodecyl sulphate/polyacrylamide electrophoresis SDS/PAGE, it was necessary to treat aqueous suspensions of the purified lectin with chloroform/methanol (2:1, v/v). The lectin remained in the aqueous layer and gave rise on SDS/PAGE to a distinct band of 65 500 +/- 2780 molecular weight. Aqueous suspensions of the purified lectin that were not subjected to extraction with chloroform/methanol gave rise to several bands. Isoelectric focussing of the purified lectin resulted in two bands that separated at pI 4.3 and 4.5. In aqueous solution in the presence of lactose the chloroform/methanol-treated lectin appears to be an aggregate of apparent molecular weight of 375 000; the non-treated lectin under the same conditions has an apparent molecular weight of 490 000.

Animals↗

Enteral exposure to crude red kidney bean lectin induces maturation of the gut in suckling pigs.

The present investigation characterized the effect of red kidney bean lectin exposure on gut maturation and function in young piglets. Eleven suckling pigs were given by stomach tube a crude red kidney bean lectin preparation (containing about 25% lectin, 400 mg/kg BW) (lectin-treated pigs) at 10, 11, and 12 d of life, and an additional 16 pigs (control pigs) were given saline instead. On the next day, the intestinal absorptive capacity was determined in vivo, and on the 14th d of life the piglets were killed and organs and small intestine samples were collected for analyses and in vitro permeability experiments. The lectin-treated pigs showed an increase in stomach weights and mucosa thickness, whereas no weight effect was found for the small intestine, spleen, liver, or adrenals. Morphometric analyses of the small intestine in lectin-treated pigs showed a decrease in villus heights, an increase in crypt depths and crypt cell mitotic indices, and fewer vacuolated enterocytes per villus and reduced vacuole size. Lectin treatment also resulted in a decrease in the absorption of different-sized marker molecules after gavage feeding, a decrease in intestinal marker permeability, and a change in small intestinal disaccharidase activities, with increased maltase and sucrase activities. The size of the pancreatic acini was also greater in the lectin-treated pigs, but no increases in enzyme content or pancreatic weight could be determined. In addition, the blood plasma levels of cholecystokinin were higher in the lectin-treated than in the control pigs. The results indicate that exposure to crude red kidney bean lectin induces structural and functional maturation of the gut and pancreatic growth in young suckling piglets. This possibility of inducing gut maturation may lead to an improvement in the piglets' ability to adapt to weaning and to an increase in the growth and health of these animals.

Animals↗

Soluble beta-galactoside specific lectin is developmentally regulated in lungs of neonatal black mice and beige mice.

The beige mouse, a mutant of the C57 black mouse, is best known as a model of the Chediak-Higashi syndrome. Recently, it was found that alveolar maturation in neonatal beige mice is impaired, resulting in abnormally large alveoli. In guinea pigs, hamsters, and rats there is an elevated activity of a soluble, beta-galactoside-binding lectin in lungs at the age when alveolar maturation is in progress. Our present studies were done to find out if the temporal relationship between elevated lectin activity and alveolar maturation also occurs in mice and, further, if the impaired alveolar maturation in beige mice might be linked to the lectin. We found that the temporal relationship between lectin activity and alveolar maturation is also present in black and beige mice, with a peak in specific lectin activity occurring at about 8 days after birth. We also found that the major lectin purified from black or beige mice has essentially the same subunit molecular weight, isoelectric point, and amino acid composition. In conclusion, we found nothing abnormal about the lectin or its developmental regulation that can explain the impaired alveolar maturation in neonatal beige mice. The results do not rule out the possibility of an important role for the lectin in normal lung development or the possibility that some aspect of function or localization of the lectin or its ligands, not related to total lung lectin hemagglutinating activity, may be altered in the beige mouse.

Animals↗

Dietary lectin lowers serum cholesterol and raises fecal neutral sterols in cholesterol-fed rats.

This study examined the influence of a low level of dietary lectin (0.34%), at a dose that did not affect body weight or food intake, on the concentration of serum cholesterol and fecal excretion of neutral sterols in rats fed a diet containing 0.50% cholesterol and 0.13% sodium cholate for 12 d. In experiment 1, rats fed a diet with 0.34% lectin, concanavalin A, had significantly lower concentrations of serum total cholesterol and hepatic cholesterol, a higher ratio of HDL-cholesterol to total cholesterol, enhanced excretion of fecal neutral sterols and reduced apparent cholesterol absorption or digestibility as compared with rats fed a diet without lectin. Fecal excretion of acidic sterols was unaffected by dietary lectin. In contrast, dietary 0.34% lectin had no significant effect on concentrations of serum total protein or glucose. In experiment 2, we examined whether the cholesterol-lowering activity of the lectin was responsibility for its carbohydrate-binding activity. The effect of dietary lectin on concentrations of serum and hepatic cholesterol and excretion of fecal neutral sterols was prevented by simultaneous administration of methyl-alpha-D-mannopyranoside with specific affinity for the carbohydrate-binding sites of the lectin. These results suggest that dietary lectins might reduce concentrations of serum and hepatic cholesterol by a mechanism involving higher excretion of neutral sterols and that these alterations might be associated with the carbohydrate-binding activity of lectin.

Animals↗

Crosslinking of lectins and receptors in membranes with hetero-bifunctional crosslinking reagents.

125I-Con A was reacted with the imidoester group of methyl 4-azidobenzoimidate and isolated from excess reagents on a Sephadex G-25 column. The hetero-bifunctional crosslinking reagent has two dissimilar functional groups, imidoester and arylazide, instead of two identical functional groups found in conventional homo-bifunctional crosslinking reagents. The two functional groups react under different conditions and it is possible to react one first and to activate the other later. Here the reagents were attached to the lectins by the imidoester reactions, and the arylazides now attached to the lectins were intended for the later use to crosslink the lectins and receptors. Human erythrocyte ghosts were incubated with the activated lectins, unbound lectins removed, and irradiated with UV to photolyze arylazides, thus crosslinking the lectins to the receptors in membranes. Upon the solubilization and subsequent electrophoresis of the sample, a new band appeared on the gel. 125I-Con A was detected in band A, the new band, and band 3, one of the membrane glycoproteins, diminished in parallel to the appearance of band A. The concurrent appearance of band A accompanied by 125I-Con A and decrease of band 3 were significantly reduced, when ghosts were incubated with the activated lectins but were not irradiated, ghosts were incubated with nonactivated 125I-Con A and irradiated, or ghosts were incubated with the activated concanavalin A in the presence of alpha-methylmannoside, the lectin inhibitor, and irradiated. The inhibitor removed a significant amount of the activated lectins bound to membranes, but failed to do so the activated lectins crosslinked into band A.

Azides↗

Expression of the galactose-binding lectins during the formation of organ primordia in the chick embryo.

Early chick embryos contain two beta-galactoside-binding lectins of 16 kDa and 14 kDa. using several antisera to these proteins, we have studied lectin expression at embryonic stages when the segregation and early differentiation of organ primordia are taking place. With antisera to the 16 kDa lectin that display similar immunoreactivity in immunoblot analysis, we show that these antisera exhibit varying immunoreactivity in embryo sections. One antiserum reacts preferentially with a matrix form of lectin while another detects mainly a cellular form of this protein. During early development, galactoside-binding lectins of the matrix type are expressed in the vitelline membrane, the outer and inner limiting membranes of the neural tube, the surface of the notochord and the coelomic surface of the cardiac rudiments. The cellular form of the lectin occurs in the intracellular yolk of early embryos, in the primordial germ cells, the myocardium, in the early myotome, and in a cohort of cells which are presumed to belong to the neural crest. Our results indicate that, although all of the antisera recognize the intracellular lectin of the extraembryonic endoderm, some antisera to the 16 kDa lectin exhibit preferential reactivity with different lectin isoforms. The extracellular matrix form of lectin is transiently expressed during early development at the stages when the segregation of organ primordia is occurring. It's expression could be related to the acquisition of polarity in developing epithelia. Results also suggest that various versions of the same protein may perform distinct developmental roles in the embryo.

Animals↗

Changes in glycoconjugate expression during early chick embryo development: a lectin-binding study.

A selection of lectins was used to investigate developmentally regulated changes in the distribution of cell surface oligosaccharides during the gastrulation and neurulation stages of early chick embryo development. Lectins from three specificity classes were used: glucose/mannose specificity (concanavalin A [Con A], Lens culinaris agglutinin [LCA], Pisum sativum agglutinin [PSA]); N-acetylglucosamine specificity (Lycopersicon esculentum agglutinin [LEA], wheat germ agglutinin [WGA], succinylated WGA [sWGA]); N-acetylgalactosamine/galactose specificity (Dolichos biflorus agglutinin [DBA], soybean agglutinin [SBA], Sophora japonica agglutinin [SJA], Bandeiraea (Griffonia) simplicifolia lectin I [BSL I], peanut agglutinin [PNA], Artocarpus integrifolia lectin [Jacalin], Ricinus communis agglutinin-1 [RCA-1], Erythrina cristagalli lectin [ECL]). At gastrulation stages, patterns of lectin binding could be distinguished in the epiblast, mesoderm, and endoderm cell layers. The primitive streak failed to bind any of the lectins, but LEA and WGA bound to the epiblast in regions lateral to the streak, indicating the loss of some glucosamine residues medially in preparation for the ingression movements of gastrulation. Several lectins showed marked binding to the mesoderm cells after their passage through the primitive streak; these were LCA, PSA, WGA, sWGA, BSL, and most particularly PNA. Therefore, the epithelial-mesenchymal transformation from epiblast to mesoderm at the primitive streak is accompanied by cell surface oligosaccharide changes in the epiblast and mesoderm that involve all classes of lectins including the PNA-binding sequence Gal beta 1-3GalNAc. Ultrastructurally, PNA was shown to bind extracellularly to matrix fibrils. Jacalin, having the same sugar specificity as PNA, but binding to serine/threonine linked chains rather than asparagine linked chains showed no binding to the mesoderm.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Mitogenic lectins bind to the antigen receptor on human lymphocytes.

The specificity of interactions between mitogenic and non-mitogenic lectins and disulfide-linked cell surface receptors on human lymphocytes was explored. Lysates (Nonidet-P40) of surface-radioiodinated tonsil lymphocytes and T lymphoblastoid cells (HPB-ALL) were absorbed with lectin-agarose derivatives (or bovine serum albumin, BSA-agarose) or immunoprecipitated with appropriate monoclonal antibodies (mAb). Lectin eluates and solubilized immunoprecipitates were analyzed by two-dimensional (nonreduced/reduced) sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Radiolabeled polypeptides were visualized by autoradiography. Among the various lectin-binding polypeptides, two disulfide-linked heterodimers (II and III) and two apparent homodimers (I and IV) are bound by pea lectin, concanavalin A and lentil lectin on tonsil lymphocytes; II, III and IV are bound both leukoagglutinating (L)- and erythroagglutinating (E)-phytohemagglutinins from Phaseolus vulgaris (PHA). Pokeweed mitogen recognizes only II and III. These molecules are weakly bound by peanut agglutinin, soybean agglutinin, Ulex europaeus agglutinin-I, Dolichos biflorus agglutinin, Vicia villosa agglutinin and Sophora japonica agglutinin, but are not bound by Helix pomatia agglutinin or BSA-agarose. Heterodimer II (82-88 kDa), comprised of 50-55-kDa and 40-43-kDa subunits, probably represents the alpha/beta T cell antigen receptor (TcR alpha/beta). Heterodimer III (64-72 kDa), comprised of 41-kDa and 37-kDa subunits, may represent TcR gamma. The homodimers, I (120-130 kDa) and IV (55-61 kDa), comprised of 55-60-kDa and 30-kDa polypeptides, respectively, have apparently not been previously described. Evidence that H1-2D4, a mAb directed against the antigen receptor on HPB-ALL cells, and E-PHA interact with a common molecule includes: (a) immunoprecipitation of TcR with H1-2D4 from the glycopeptide fraction specifically eluted from insolubilized lectin with N-acetylgalactosamine; and (b) adsorption of TcR from a solubilized H1-2D4 immunoprecipitate by E-PHA-agarose. Recognition of CD3 by E-PHA is indicated by immunoprecipitation of CD3 protein by UCHT1 from the glycopeptide fraction specifically eluted from E-PHA. The results are consistent with the view that mitogenic lectins interact with certain disulfide-linked molecules on human lymphocytes, including the TcR alpha/beta and perhaps TcR gamma; while some nonmitogenic lectins also recognize these receptors, the interaction is of low affinity.

Agglutinins↗

Vitelline coat of Unio elongatulus: III. Glycan chain analysis of the 220- and 180-kD components by means of lectins.

Lectins of different binding specificity were used to analyze the oligosaccharide chains of the 220- and 180-kD proteins of the Unio elongatulus egg vitelline coat (vc). The lectins ConA and RCA1 reacted with both glycoproteins, and four other lectins reacted with one or other vc components. The lectin from Galanthus nivalis, which recognizes terminal mannose residues of N-linked high mannose type oligosaccharide chains, bound specifically to the 180-kD protein. Binding sites for this lectin were found throughout the vc of the differentiating oocyte and the mature egg. Lectins specific for the O-linked oligosaccharide chains, such as AIA and PNA, reacted only with the 220-kD protein species. Binding sites for these lectins were found only in the crater region. The presence of fucosyl residues on the glycan chains was investigated with lectins from Lotus tetragonolobus and Aleuria aurantia. The latter was positive on both glycoproteins, whereas LTA was only positive to the 220-kD species. The binding sites of both these lectins were in the same areas as those of PNA and AIA. These results suggest that while the 180-kD protein is part of the entire vc structure, the 220-kD protein is prevalently accumulated in the crater region. Since this is where sperm recognition and interaction take place, it has been suggested the 220-kD protein acts as a ligand molecule in the sperm-egg interaction.

Animals↗

Cloning and characterization of the lectin cDNA clones from onion, shallot and leek.

Characterization of the lectins from onion (Allium cepa), shallot (A. ascalonicum) and leek (A. porrum) has shown that these lectins differ from previously isolated Alliaceae lectins not only in their molecular structure but also in their ability to inhibit retrovirus infection of target cells. cDNA libraries constructed from poly(A)-rich RNA isolated from young shoots of onion, shallot and leek were screened for lectin cDNA clones using colony hybridization. Sequence analysis of the lectin cDNA clones from these three species revealed a high degree of sequence similarity both at the nucleotide and at the amino acid level. Apparently the onion, shallot and leek lectins are translated from mRNAs of ca. 800 nucleotides. The primary translation products are preproproteins (ca. 19 kDa) which are converted into the mature lectin polypeptides (12.5-13 kDa) after post-translational modifications. Southern blot analysis of genomic DNA has shown that the lectins are most probably encoded by a family of closely related genes which is in good agreement with the sequence heterogeneity found between different lectin cDNA clones of one species.

Allium↗

Carbohydrate-binding specificity of the daffodil (Narcissus pseudonarcissus) and amaryllis (Hippeastrum hybr.) bulb lectins.

The carbohydrate binding specificity of the daffodil (Narcissus pseudonarcissus; NPA) and amaryllis (Hippeastrum hybr.; HHA) lectins, isolated from extracts of their bulbs by affinity chromatography on immobilized mannose, was studied by quantitative precipitation, sugar hapten inhibition, and affinity chromatography on the immobilized lectins. These lectins gave strong precipitation reactions with several yeast mannans, but did not precipitate with alpha-D-glucans (e.g., dextrans and glycogen). Interestingly, both lectins reacted strongly with yeast galactomannans having multiple nonreducing terminal alpha-D-galactosyl groups, a synthetic linear alpha-1,6-mannan, and an alpha-1,3-mannan (DP = 30). Treatment of the linear alpha-1,3-mannan with periodate, resulting in oxidation of the terminal, nonreducing mannosyl group, did not reduce its reactivity with NPA or HHA. Taken together, these observations suggest that NPA and HHA react not only with terminal but also with internal alpha-D-mannosyl residues. Sugar hapten inhibition studies showed these lectins to possess the greatest specific activity for alpha-D-mannosyl units whereas D-Glc and D-GlcNAc did not inhibit either lectin precipitation system. Of the oligosaccharides tested, the best inhibitor of NPA interaction was alpha-1,6-linked mannotriose, which was twice as good an inhibitor as Man alpha 1,6Man alpha-O-Me and 10 times better than methyl alpha-D-mannoside. On the other hand, oligosaccharides containing either 1,3- or 1,6-linked mannosyl units were good inhibitors of the HHA-mannan precipitation system (6- to 20-fold more active than D-Man). These results indicate that both lectins appear to possess an extended binding site(s) complementary to at least three 1,6-linked alpha-mannosyl units. Various glycosylasparagine glycopeptides which contain alpha-1,6-Man units were retarded on the immobilized NPA column. On the other hand, those containing either alpha-1,3- or alpha-1,6-mannosyl residues were retarded on the immobilized HHA column; Man5-GlcNAc2-Asn [containing two Man alpha 1,3(Man alpha 1,6) units] bound to the HHA column. On the contrary, glycopeptides with hybrid type glycan chains were not retarded on either column. These two new lectins which differ in their fine sugar binding specificity from each other, and also from the snowdrop lectin, should prove to be useful probes for the detection and preliminary characterization of glycoconjugates on cell surfaces and in solution.

Binding, Competitive↗

Immunosorbent assay of interactions between human parotid immunoglobulin A and dietary lectins.

By enzyme-linked immunosorbent assay (ELISA), parotid IgA was found to associate with purified peanut (PNA), pea (PSA) and wheat-germ (WGA) lectins. To determine the effect of eating foods which contained these lectins on the reactivity of IgA with purified lectins, samples of parotid saliva were collected prior to, and after, eating the lectin-containing food and their reactivity determined by ELISA. Four of 5, and 5 of 6 subjects, respectively, gave one or more post-eating samples with increased IgA reactivity to purified PNA or PSA, but not to WGA, a heterologous lectin. Four of 6 subjects had significantly higher IgA reactivity with PSA after they ate raw peas on a single occasion. Absorption experiments with PSA and PNA conjugated to agarose beads showed there were different populations of IgA molecules which reacted with the lectins. One highly-reactive population increased after eating the lectin-containing food and may contain antibodies induced by antigenic determinants in the lectin. The lectins may also bind to saccharide moieties of the IgA molecules.

Adult↗

The cell surface of isolated cardiac myocytes--a light microscope study with use of fluorochrome-coupled lectins.

In cells isolated from guinea-pig or rat ventricular muscle occurrence and distribution of carbohydrate components of the surface coat were monitored using fluorochrome-coupled lectins. Fluorescence of membrane-bound lectins was assayed by an image analysis system. The lectins ConA, WGA, sWGA, LFA and RCA-I showed specific binding to the whole myocyte surface, indicating a homogeneous distribution of alpha-mannosyl, alpha-glycosyl, N-acetylglucosaminyl, N-acetylneuraminate and beta-galactosyl residues. Binding of DBA and SBA, with specific affinity for N-acetylgalactosaminyl residues, to guinea-pig cardiac myocytes was mainly at the cell poles corresponding to intercalated discs in intact tissue. Both lectins failed to interact with rat myocytes. UEA-I, specific for alpha-L-fucose, bound slightly to rat and not to guinea-pig myocytes. Binding of PNA to guinea-pig myocytes was observed only after cleaving off sialic acids from cell surface, suggesting that sialic acids mask galactosyl-beta(1,3)-N-acetylgalactosamine residues. Specificity of lectin-cell interaction was tested by an inhibition assay where free sugars were tested for their capacity to inhibit lectin binding to the myocytes. When comparing different isolation procedures based on different proteolytic enzymes, the myocytes' affinity to any lectin was found to be qualitatively unchanged. Investigation of lectin-decorated myocytes by means of confocal laser scan microscopy showed that lectin binding sites are not confined to the cell surface but are also present in sarcolemmal invaginations, i.e. transverse tubules. This suggests that the tubular system is lined with a carbohydrate layer similar to, and continuous with, that of the peripheral cell surface.

Animals↗

Lectins and the radioallergosorbent test.

An investigation into the possible role of lectin binding of IgE in RAST of legume and wheat extracts is reported. Lectins from pea, broad bean, lentil, jack bean, soybean, peanut, and wheat germ were coupled to RAST discs. The discs were pretreated with lectin-specific sugars in an attempt to inhibit RAST with sera from 11 sensitive patients. In all cases, RAST was almost unaffected by the inhibitory sugars, indicating that nonimmune binding of IgE by lectins in legume or wheat RAST was not significant when RAST was carried out with allergens bound to the usual paper discs. IgE contains binding sites for all the lectins examined, and five of the sera had high total IgE greater than 300 IU/ml. It is suggested that competition by IgG and other serum glycoproteins may explain the lack of effect by the added sugars. All sera contained endogenous glucose at a level of about 3 mmol/L that may have accounted for some self-inhibition of the lectin binding by pea, broad bean, lentil, and jack bean lectins. There was, however, significant immune binding of some of the lectins by specific IgE, and it is concluded that these lectins may be important in expression of IgE-mediated allergic responses.

Arachis↗

Lectins as probes for the assay of rhabdovirus infections in plants.

Thirteen different, biotinylated plant lectins were tested for their ability to recognize specifically the glycoproteins of the two different plant rhabdoviruses potato yellow dwarf virus and eggplant mottled dwarf virus. All viruses were propagated on the same plant host species, Nicotiana rustica L. The lectin-binding to the viral proteins was tested after electrophoretic separation and transfer to nitrocellulose membranes. Besides purified virus also partially pure virus preparations were used for the tests, in order to determine the specificity. The lectins had been selected for specificities to either one of the following monosaccharides: mannose, glucose, galactose, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine and fucose. In the test panel of thirteen lectins, seven were found to react with the viral glycoproteins. Among these, four (LCA, VFA, PSA, Con A) belonged to the mannosyl- or glycosyl-specific group. However, these four lectins reacted also with other host proteins when partially pure virus preparations were used as samples. The other three lectins (GSA2b, STA, WGA) were specific for N-acetyl-D-glucosamine and detected almost exclusively the viral glycoproteins. Two of these lectins, STA and WGA, were extremely suitable for virus-specific assays, since they did not react with glycoproteins in healthy controls that were identical or comparable in their electrophoretic mobility with the rhabdovirus glycoproteins. No binding to viral glycoproteins was observed with galactose-, N-acetyl-galactosamine- and fucose-specific lectins. The assay for rhabdovirus glycoproteins in plants with the lectins was approximately 8-16 times less sensitive than with virus-specific antibodies.

Glycoproteins↗

Bandeiraea simplicifolia lectin I and Vicia villosa agglutinin bind specifically to the vomeronasal axons in the accessory olfactory bulb of the rat.

The binding of 21 lectins to the accessory olfactory bulb (AOB) of the rat was examined by histochemistry. Two lectins [Bandeiraea simplicifolia lectin I (BSL-I) and Vicia villosa agglutinin (VVA)] bound specifically to the vomeronasal (VN) axons in the AOB. Seven lectins (Datura stramonium lectin, Erythrina cristagalli lectin, Lycoperisicon esculentum lectin, Ricinus communis agglutinin I, soybean agglutinin, Solanum tuberosum lectin, and Ulex europaeus agglutinin) bound to both VN axons in AOB and olfactory axons in the main olfactory bulb. BSL-I and VVA are useful as the marker of VN axons. This selective binding of lectins indicates the presence of specific glycoconjugates on the surface of VN axons.

Animals↗

Expression of galactoside-specific endogenous lectins and their ligands in human oral squamous cell carcinoma.

Human endogenous lectins have a wide spectrum of biological functions. The present study analyses the expression of beta-galactoside specific and N-acetyl-D-galactosamine specific endogenous lectins in oral squamous cell carcinomas using biotinylated neoglycoproteins. The expression pattern of beta-galactosyl-containing glycoconjugates or ligands of beta-galactoside specific lectins in these tissues was also studied using an endogenous biotinylated lectin, the human 14-kDa lectin. For comparison a galactoside specific plant lectin from mistletoe, Viscum album was also employed. The results demonstrate that oral squamous cell carcinomas mainly express accessible binding sites for lactosylated neoglycoprotein (90%) while few carcinomas expressed mild amount of N-acetyl-D-galactosamine specific binding sites (40%). There was no difference in the binding patterns of these probes between well and less differentiated carcinomas. Expression of these neoglycoprotein binding sites were mostly concentrated in immature basaloid cells, indicating a possible association with cell proliferation. The binding pattern of D-galactosyl specific lectins (human 14-kDa and mistletoe lectins) showed conspicuous differences. This feature emphasizes the caution that needs to be exercised in interpreting the biological significance of results attained using plant lectins on human tissue.

Acetylgalactosamine↗