Five alpha-D-galactopyranosyl-binding isolectins from Bandeiraea simplicifolia seeds

Histochemical demonstration of sugar residues by lectin and immunocytochemical techniques for blood group antigens in human colon

Goblet cell mucin in 39 human colons was studied by methods specific for various sugar residues, including staining with three lectins, Dolichos biflorus agglutinin (DBA, specific for blood group A antigen), Griffonia simplicifolia agglutinin-I (GSA-I, B) and peanut agglutinin (PNA, T antigen), and immunostaining for A, B, H and T. Isoantigens A, B or H were found only in the right colon. GSA-I reactive goblet cells occurred in the right colon of both blood group A and B patients and possibly contained isoantigens. However DBA reactive cells were found in all cases. Prior neuraminidase digestion imparted anti-A, GSA-I and DBA reactivities to the cells lining the lower crypts in all cases. This pretreatment also imparted PNA and anti-T reactivities to goblet cells, only the latter reactivity being eliminated by galactose oxidase. Goblet cell mucin in transitional mucosa revealed decreased A and B, and increased H antigens. Enhanced galactose oxidase-Schiff (GOS) and anti-T reactivities were also noted. The present results revealed that some lectin reactions of goblet cells might be related to blood group antigens but others were not, and that different techniques for demonstrating reputedly the same sugar residues produced different results, indicating a need for proper evaluation of their specificity.

A monoclonal antibody reacting with the zona pellucida of the oviductal egg but not with that of the ovarian egg of the golden hamster

A monoclonal antibody (mAb) designated AZPO-8 was produced by hybridizing a mouse myeloma with spleen cells from BALB/c mice immunized with materials obtained from the hamster oviduct. With an immunofluorescence test, AZPO-8 reacted with the zona pellucida (ZP) of ovulated eggs in the oviduct (ZP-OVI) but not with the zona pellucida of eggs in the ovary (ZP-OVA). Using indirect enzyme immunostaining, this mAb reacted with epithelial cells of the oviduct, the uterus (especially the cervical epithelium) and the gastric mucosa, but not with other hamster tissues examined. The reactivity of antigen-positive tissues was abrogated by pretreatment of the tissues with periodic acid. Western blotting analysis revealed that AZPO-8 reacted with substances of broad molecular weight range, and the strongest reactivity was detected at a molecular weight of approximately 200,000 in both cases when extract of ZP-OVI or the hamster oviduct was applied on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) gel. AZPO-8 showed strong hemagglutination activity only to group A human red blood cells. These results indicated that (1) ZP-OVI had an antigen that was not detected on ZP-OVA, (2) ZP-OVI and the oviduct shared the same antigenicity, and (3) the antigenic determinant reactive with the mAb might be carbohydrate in nature. A possible role of this antigen in fertilization was discussed.

A new agglutinin from the Tulipa gesneriana bulbs

Two agglutinins with different agglutinating activity exist in Tulipa gesneriana bulbs. One is the T. gesneriana lectin which agglutinates yeasts as reported previously [Oda, Y. and Minami, K. (1986) Eur. J. Biochem. 159, 239-245]. The other agglutinin is a new one which agglutinates animal erythrocytes and was purified from the tulip bulbs using affinity chromatography on thyroglobulin-Sepharose 4B. The agglutinin agglutinated mouse and rat erythrocytes at a minimum concentration of 2 micrograms/ml and 30 micrograms/ml respectively, but did not agglutinate erythrocytes from other animals and yeasts even at a concentration of 1000 micrograms/ml. The agglutinin appeared homogeneous by disc gel electrophoresis at pH 4.3 and gel filtration. Its relative molecular mass was determined by gel filtration to be approximately 40,000. It was suggested that the agglutinin was composed of two different subunits of 26 kDa and 14 kDa by sodium dodecyl sulfate/polyacrylamide gel electrophoresis analysis. Binding of radioiodinated agglutinin to mouse erythrocytes indicated that the presence of a high-affinity site with a dissociation constant of 2.00 X 10(-9) M. In inhibition experiments thyroglobulin glycopeptides were the most potent inhibitors; thyroglobulin was also a potent inhibitor. Orosomucoid and mucin showed weak inhibition. The other glycoproteins, glycopeptides and sugars examined showed no inhibition.

Griffonia simplicifolia lectins bind specifically to endothelial cells and some epithelial cells in mouse tissues

The binding of Griffonia simplicifolia agglutinin-I (GSA-I) and the isolectins GSA-I-AB3 and GSA-I-B4, having affinity for some alpha-D-galactosyl and N-acetyl galactosaminyl residues was studied in different mouse tissues. In brain, cardiac muscle and skeletal muscle, the GSA-I-lectin conjugates showed prominent binding only to blood vessel endothelia. Similarly, in the liver and kidney cortex the GSA-I-conjugates selectively reacted with endothelial cells of the sinusoids and with intertubular and glomerular capillaries, respectively. However, a strong reactivity with the GSA-I-conjugates was additionally seen in the acinar cells of the pancreas, in the stratified squamous epithelia of skin and tongue, and in transitional epithelium. SDS-PAGE electrophoresis combined with the lectin-blotting technique indicated that a similar set of glycoproteins are responsible for the GSA-I binding, even in different tissues. Another lectin with specificity for alpha-D-galactose, the Maclura pomifera agglutinin, displayed a distinctly different distribution of binding sites, mainly in the basement membranes, of all mouse tissues studied. The results suggest that some alpha-D-galactosyl residues, recognized by the binding of GSA-I lectins, are preferentially expressed in endothelial cells of mouse tissues, and also provide further evidence that endothelial cells can present a highly specific surface glycosylation pattern.

Occurrence in Bacillus megaterium of uridine 5'-diphospho-N-acetylgalactosamine and uridine 5'-diphosphogalactosamine, intermediates in the biosynthesis of galactosamine-6-phosphate polymer

We isolated two galactosamine derivatives from Bacillus megaterium sporulating cells by lectin affinity chromatography followed by DEAE-Sephadex A-25 chromatography. From chemical analyses and measurements of these compounds, it was determined that one was uridine 5'-diphospho-N-acetylgalactosamine and that the other was uridine 5'-diphosphogalactosamine. They appeared in the middle stage of sporulation and disappeared during the period when galactosamine-6-phosphate is deposited on the forespore surface. These results suggest that uridine 5'-diphospho-N-acetylgalactosamine and uridine 5'-diphosphogalactosamine are intermediates in the biosynthesis of the galactosamine-6-phosphate polymer, a backbone structure of the exosporium.

Griffonia simplicifolia I isolectin as a functionally monovalent probe for use in flow cytometry

The inherent tendency of lectins to agglutinate cells has limited their use as reagents for the detection of carbohydrate groups on cell surfaces by flow cytometry. In the current study, we demonstrate a method for the use of a fluoresceinated tetrameric isolectin (Griffonia simplicifolia I-A3B, FITC-GS I-A3B) as a functionally monovalent, nonagglutinating probe in flow cytometry. This isolectin contains three A subunits and one B subunit. Both types of subunits bind alpha-D-galactopyranosyl (alpha-D-galp-) end groups with similar affinities; however, the A subunits have a 1,000-fold greater affinity for N-Acetyl-D-galactosamine (GalNAc) than does the B subunit. The addition of low (1-2 mM) concentrations of GalNAc to the FITC-GS I-A3B isolectin results in blockage of the three A subunits without significantly affecting the B subunit; this yields a functionally monovalent probe for the detection of cell surface alpha-D-Galp end groups. This approach has been used to examine two types of cells: Ehrlich ascites tumor cells and rat alveolar macrophages, both of which are known to express cell surface alpha-D-Galp end groups. Lectin binding, as determined by number of positive cells and fluorescence intensity, was dependent upon concentration of the lectin and haptenic sugar. Specificity of the staining was demonstrated by the ability of methyl alpha-D-galactopyranoside (Met alpha-D-Galp) to abolish the binding of the lectin to the cells. Elimination of both GalNAc and Met alpha-D-Galp from the staining solution resulted in agglutination of the cells, indicating that the A subunits were active in the absence of GalNAc.

Binding of Griffonia simplicifolia I lectin to rat pulmonary alveolar macrophages and its use in purifying type II alveolar epithelial cells

We report that the isolectin Griffonia simplicifolia I-B4 isolated from G. simplicifolia seeds binds to rat alveolar macrophages present in frozen sections of lung tissue or bronchoalveolar lavage fluid. G. simplicifolia I-B4 does not bind to alveolar epithelial cells. We established that G. simplicifolia I-B4 binds to the macrophages via interaction with terminal alpha-D-galactopyranosyl residues present on these cells. This was substantiated by demonstrating that binding is inhibited either by the haptenic sugar alpha-D-galactopyranoside or by treating the cells with coffee bean alpha-galactosidase. Because murine laminin is known to contain terminal alpha-D-galactopyranosyl end-groups, and because we found that an anti-laminin antiserum binds to rat alveolar macrophages, we suspect that G. simplicifolia I-B4 may be binding to laminin present on the macrophages. To isolate alveolar type II epithelial cells from rat lungs, we developed a method that utilizes the lectin G. simplicifolia I. When proteinase-derived suspensions of pulmonary cells are incubated with G. simplicifolia I, the macrophages agglutinate and can be removed by filtration through nylon mesh. After incubating the resulting cellular suspension in tissue culture, the adherent cells are 94 +/- 2% (S.D.) type II cells. When compared to cells isolated by repeated differential adherence, the lectin-prepared type II cells have similar morphology and staining characteristics, form domes in monolayers and incorporate similar amounts of palmitate into disaturated phosphatidylcholine. We believe that the procedure outlined in this report provides a simple and effective method to isolate type II alveolar epithelial cells from rat lungs.

Affinity chromatography on immobilized hog gastric mucin and ovomucoid. A general method for isolation of lectins

Two affinity adsorbents of general applicability for isolating of plant lectins are presented. The isolation of 30 lectins from 27 plants is described. The method works quickly and is inexpensive. In particular, mixtures of different lectins occurring in some plants may be resolved in one run.

2-Substituted methyl alpha-D-galactopyranosides: synthesis and binding affinity for the A and B subunits of the Griffonia simplicifolia I isolectins

The binding affinities of the N-acetyl, N-trifluoroacetyl, N-propionyl, N-formyl, N-benzoyl, N-p-nitrobenzoyl, N-p-aminobenzoyl, and N-methyl derivatives of methyl 2-amino-2-deoxy-alpha-D-galactopyranoside and the 2-O-acetyl, -benzoyl, -benzyl, and -methyl derivatives of methyl alpha-D-galactopyranoside for the A and B subunits of the Griffonia simplicifolia I isolectins have been determined by hapten inhibition analysis of a galactomannan-isolectin precipitation system. Models for these carbohydrate-protein interactions are presented together with an interpretation of the results on the basis of electronic and steric effects.

Probing the topography of lectins with site-specific spin-labeled glycosides

Three new spin-labeled glycosides, spin-label I [1-[4-(beta-D-galactopyranosyloxy)phenyl]-3-(2,2,6,6-tetramethyl-1 -oxypiperidin-4-yl)-2-thiourea], spin-label II (2,2,6,6-tetramethyl-1-oxypiperidin-4-yl alpha-D-galactopyranoside), and spin-label III [1-(methyl 2-deoxy-alpha-D-galactopyranosid-2-yl)-3-(2,2,6,6- tetramethyl-1-oxypiperidin-4-yl)-2-thiourea], were investigated as structural probes of Griffonia simplicifolia I isolectins (GS I) A4 and B4, respectively, by electron spin resonance (ESR) and inhibition of guaran isolectin precipitation. The p-aminophenyl beta-galactoside spin-label I was strongly immobilized by the B4 isolectin (Kd = 0.42 mM; 2T parallel = 54.0 +/- 0.3 G), while binding to the A4 isolectin was so weak (KI congruent to 2 mM) that binding was undetectable by ESR. The preference for the B4 isolectin was indicative of a more extended hydrophobic binding locus adjacent to the carbohydrate-specific binding site. The alpha-galactosyl spin-label II bound slightly more strongly to the A4 than to the B4 isolectin, as evidenced in both Kd values and particularly by differences in the degree of immobilization (2T parallel = 53.5 vs. 51.5 G, respectively). The 2-N-substituted methyl galactoside spin-label III was so poor an inhibitor of both isolectins (KI congruent to 1-2 mM) that ESR detection of the bound complex was not feasible. In all cases above, the spin-labels were displaced by specific monosaccharide haptens.

Attachment, spreading and growth in vitro of highly malignant and low malignant murine fibrosarcoma cells

Highly malignant cell lines and low-malignant cell lines isolated from three different methylcholanthrene-induced murine fibrosarcomas were examined for their ability to attach to plastic dishes and collagen-coated dishes under serum-free conditions and in the presence of serum. Most of the cells from the three highly malignant lines attached and spread under all conditions. By 72 h, there was a significant increase in the number of cells indicating that at least some of the cells had undergone division (even in the absence of serum). In contrast, fewer of the cells from the three low-malignant lines attached and spread on the plastic or collagen substrates in the absence of serum or in the presence of 0.1 per cent serum. However, when 15 micrograms laminin per dish was added along with the low-malignant cells, they then attached and spread on the plastic and collagen-coated dishes. Previous studies have indicated that the highly malignant lines express cell surface antigens that cross-react with laminin while the low-malignant cell lines do not. We speculate that the differences between the high- and low-malignant cells in the expression of cell surface laminin-like antigens contribute to the dissimilarities in attachment and spreading capacity. These differences may also contribute to the dissimilarity between these cells in malignant potential.

Contribution of alpha-D-galactopyranosyl end groups to attachment of highly and low metastatic murine fibrosarcoma cells to various substrates

There are much greater numbers of cell surface terminal, non-reducing alpha-D-galactorpyranosyl groups in highly malignant (metastatic) cells than are found in low malignant cells derived from the same murine fibrosarcoma. We have examined the contribution of these residues to attachment of the cells to various collagens and to plastic. Removal of these carbohydrate groups with alpha-galactosidase or blocking them with lectins from Griffonia simplicifolia seeds or with anti-blood group B antiserum all dramatically inhibited the attachment of both the highly malignant and the low malignant cells. Following removal with the enzyme, the alpha-D-galactopyranosyl end groups were rapidly resynthesized. This resynthesis was inhibited by tunicamycin, an inhibitor of de novo glycoprotein synthesis. This antibiotic also impaired cell attachment and, when used in addition to treatment with alpha-galactosidase, it inhibited cell attachment more than did treatment with the enzyme alone. The effects of all treatments on cell attachment were greater for the highly malignant than for the low malignant cells. With the latter cells, inhibition by lectin was seen only in the absence of serum, whereas the adhesion of highly malignant cells was affected in both the presence and the absence of serum. On their surface membrane the highly malignant cells express much more than do the low malignant cells of a glycoprotein that cross-reacts immunologically with laminin. The basement membrane glycoprotein laminin promotes cell attachment to collagen, and both glycoproteins contain terminal, non-reducing alpha-D-galactopyranosyl groups. Attachment of cells is a requirement for the formation of a metastasis, and thus the laminin-like molecule and the alpha-D-galactopyranosyl end groups (whether on the laminin-related moiety or on other cell surface molecules) may both be important for expression of the most malignant phenotype.

Reexamination of the carbohydrate binding stoichiometry of lima bean lectin

The carbohydrate binding stoichiometry of lima bean lectin component III was reexamined using equilibrium dialysis and quantitative affinity chromatography following limited chemical modification. Equilibrium dialysis employing methyl[2-14C]benzamido-2-deoxy-alpha-D-galactopyranoside as ligand demonstrated that the lectin tetramer bound 4 mol of sugar with Kassoc = 1.44 +/- 0.13 X 10(3) M-1 (T = 5 degrees C, pH 7.0, ionic strength 0.1). The previous report of two sites/tetramer [Bessler, W. and Goldstein, I. J. (1974) Arch. Biochem. Biophys. 165, 444] appears to be the result of partial inactivation of the lectin due to oxidation of essential thiol groups. Following limited chemical modification of the thiol groups by methyl methanethiosulfonate, multiple intermediate forms with reduced affinity for Synsorb A were obtained. The number and hemagglutinating activities of these intermediates provided further support for the presence of four carbohydrate binding sites on lima bean lectin component III.

Enzyme-linked lectin assay (ELLA). II. Detection of carbohydrate groups on the surface of unfixed cells

An enzyme-linked lectin assay (ELLA) has been developed to detect specific carbohydrate units on the surface of unfixed cells. The assay may be read in standard ELISA plate readers, since the cell-bound enzyme-lectin conjugate is specifically eluted from the cells prior to development of the conjugate. ELLA, when read in an enzyme-linked immunosorbent assay (ELISA) plate reader, allows better detection and relative quantitation of specific surface carbohydrate units than is possible by standard immunofluorescence with fluorescein-conjugated lectins.

A structural comparison of the A and B subunits of Griffonia simplicifolia I isolectins

A structural comparison between the A and B subunits of the five tetrameric Griffonia simplicifolia I isolectins (A4, A3B, A2B2, AB3, B4) was undertaken to determine the extent of homology between the subunits. The first 25 N-terminal amino acids of both A and B subunits were determined following the enzymatic removal of N-terminal pyroglutamate blocking groups with pyroglutamate aminopeptidase. Although 21 amino acids were common to both subunits, there were four unique amino acids in the N-terminal sequence of A and B. Residues 8, 9, 17, and 19 were asparagine, leucine, lysine, and asparagine in subunit A and threonine, phenylalanine, glutamic acid, and serine in subunit B. The last six C-terminal amino acids, released by digestion with carboxypeptidase Y, were the same for both subunits: Arg-(Phe, Val)-Leu-Thr-Ser-COOH. Subunit B, which contains one methionyl residue, was cleaved by cyanogen bromide into two fragments, a large (Mr = 31,000) and a small (Mr = 2700) polypeptide. Failure of the small fragment to undergo manual Edman degradation indicated an N-terminal blocking group, presumably pyroglutamate. Both subunits were digested with trypsin and the tryptic peptides were analyzed using reverse-phase HPLC. Tryptic glycopeptides were identified by labeling the carbohydrate moiety of the A and B subunit using sodium [3H] borohydride. Cysteine-containing tryptic peptides were similarly identified by using [1-14C]iodoacetamide. Approximately 30% of the tryptic peptides were common to both subunits. Thus, although the N- and C-terminal regions of A and B are similar, the subunits each possess unique sequences.

Purification and properties of the basic lectins from winged bean seed [Psophocarpus tetragonolobus (L.) DC]

The seeds of winged bean, Psophocarpus tetragonolobus (L.) DC, contain a group of acidic lectins (pI approximately equal to 5.5) and a group of basic lectins (pI greater than 9.5) characterised by different erythrocyte hemagglutinating specificities. Three basic lectins were separated and purified to apparent homogeneity by chromatography on Ultrogel AcA44 and SP-Sephadex C-25. These lectins are glycoproteins with relative molecular mass of 58 000. The total carbohydrate content of the major lectins, B2 and B3, was 5% and was comprised of mannose, N-acetylglucosamine, fucose and xylose in amounts corresponding to 9, 8, 8 and 3 mol/58 000 g, respectively, for both lectins. Electrophoresis in dodecyl sulfate gave a single subunit of relative molecular mass 29 000 for each lectin. Isoelectric focusing in 8 M urea revealed two differently charged subunits in each of the isolated lectins; a total of three different subunits in the three lectins was observed. The basic lectins have essentially the same amino acid composition and contain no half-cystine. Two of the lectins (B2 and B3) showed identical amino-terminal sequences and the sequence of lectin B3 to residue 40 revealed extensive homology with other legume lectins such as soybean lectin. The basic lectins agglutinated trypsinized rabbit and trypsinized human (type A and B) erythrocytes but not trypsinized human (type O) erythrocytes. The lectins were inhibited by N-acetylgalactosamine, D-galactose and D-galactose containing disaccharides and trisaccharides. The specificity appears to be directed to glycosides having non-reducing (terminal) alpha-D-galactopyranosyl groups. beta-D-Galactosides, such as lactose, are poor inhibitors.

The interaction of lactose-specific lectins with acid-treated and lactose-substituted sepharose

The binding of two lectins, one a galactosyl/lactosyl and the other a lactosyl binding protein, to various Sepharose 4B derivatives has been investigated. The adsorbents, lactose-substituted Sepharose, acid-treated Sepharose and acid-treated, lactose-substituted Sepharose, were each tested with regard to their overall binding capacity and for the ability to separate the lectins by differential elution with solutions of galactose and lactose. The binding capacity for both lectins decreased in the order Lac-acid-Sepharose greater than Acid-Sepharose greater than Lac-Sepharose much greater than Untreated Sepharose. The ability of the gels to bind both lectins with a sufficient affinity to allow the proteins to be purified by differential elution decreased in a similar order. Acid-treated, lactose-substituted Sepharose proved the most useful gel and was utilised to isolate each lectin in a pure form.

Comparative study of procedures for histological detection of lectin binding by use of Griffonia simplicifolia agglutinin I and gastrointestinal mucosa of the rat

The histological localisation of alpha-D-galactopyranosyl residues in glycoconjugates of rat stomach and duodenal mucosae was studied by use of Griffonia simplicifolia agglutinin I, i.e. the isolectin mixture (A + B) and the isolectin B4 (B4). Cryostat sections which were either unfixed or acetone fixed and paraffin sections from both ethanol-acetic acid and formaldehyde fixed tissue blocks were compared. Cellular details were better preserved in paraffin than in cryostat sections. Reactivity of cells binding GS I was less sensitive after formaldehyde than after ethanol-acetic acid fixation inasmuch as higher concentrations of lectins were needed. This drawback could be overcome by trypsinisation of the sections. The binding pattern of GS I (A + B) corresponded with that of GS I (B4) in either cryostat or paraffin sections. GS I was detected in the cytoplasm of parietal cells and in Brunner's gland cells. In duodenal crypts and villi, lectin was bound to supranuclear regions in the cytoplasm of columnar and goblet cells. The staining efficiency of fluorescein (FITC), horseradish peroxidase (HRP) and colloidal gold particle (CGP) labels in both direct and indirect lectin stainings was compared. Under all experimental conditions, indirect methods required lower concentrations of lectins than direct ones; indirect procedures increased sensitivity about 5-10 fold. CGP labels were always of highest sensitivity when gold particles were further developed by a silver precipitation method. HRP was not as efficient in lectin localisation as CGP, but cytochemical staining was more convenient in routine work. Direct FITC labellings proved to be of lowest sensitivity.

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.

Fluorescein-conjugated Bandeiraea simplicifolia lectin as a marker of endodermal, yolk sac, and trophoblastic differentiation in the mouse embryo

The Bandeiraea simplicifolia lectin I (BSA-I) conjugated to fluorescein isothiocyanate was used as a histochemical reagent to study the mouse embryos from fertilization to early somitogenesis. No lectin binding could be detected on the embryonic cells in the preimplantation embryo. Lectin labeled intensely the zona pellucida. In the implanting embryos lectin binding was detected along the subtrophectodermal and Reichert's membrane, in the cytoplasm of the parietal and visceral endoderm, and the trophoblastic giant cells, but not in the ectodermal cells. Studies on explanted blastocyts cultured in vitro disclosed that the cytoplasmic BSA-I binding sites in trophoblastic cells develop gradually. In the 9-day somitic embryo BSA-I reacted with epithelial cells of the yolk sac, but not with the mesenchymal cells. A continuity between the lectin-reactive endoderm and the foregut epithelium could be demonstrated. These data indicated that BSA-I lectin can be used as a histochemical probe for endodermal (yolk sac) and trophoblastic differentiation in the peri-implantational mouse embryo.

Enzyme-linked lectin assay (ELLA): use of alkaline phosphatase-conjugated Griffonia simplicifolia B4 isolectin for the detection of alpha-D-galactopyranosyl end groups

Alkaline phosphatase has been coupled to Griffonia simplicifolia I B4 isolectin using a one-step glutaraldehyde conjugation procedure. This enzyme-lectin conjugate (AP-GS I-B4) has been used to specifically detect plastic-bound natural and synthetic glycoproteins bearing alpha-D-galactopyranosyl end groups. The extent of reactivity of the AP-GS I-B4 with the glycoproteins appears to be proportional to the number of terminal galactosyl residues present. Furthermore, this assay, termed ELLA (enzyme-linked lectin assay), is specifically inhibitable by low-molecular-weight sugars containing terminal alpha-D-galactosyl groups. The ELLA reactions may be assayed rapidly and objectively by the use of commercially available ELISA-plate using standard filters.

Distribution of Bandeiraea simplicifolia lectin binding sites in the genital organs of female and male mice

Fluorescein isothiocyanate labelled type I lectin from Bandeiraea simplicifolia (BSA-I) known for its specific binding to alpha-D-galactopyranosyl and 2-acetamido-2-deoxy-D-galactose groups, has been used to map the distribution of the lectin specific binding sites in the genital organs of female and male mice. In non-pregnant female mice, strong lectin reactivity was restricted to the epithelium of the distal oviduct, the cervix and vagina. In pregnant mice strong BSA-I reactivity was also noted in the epithelium of uterine glands from the time of implantation on day 5 onward. In the testis BSA-I bound selectively to sperm but did not react with other cells in the seminiferous tubules. In the proximal caput epididymis BSA-I reacted with the epithelial cells, the underlying basement membranes and the intraluminal sperm. The intraluminal contents of the seminal vesicles reacted strongly with the lectin. Our data thus show a widespread but selective distribution of BSA-I lectin binding sites in the male and female genital organs and altered lectin binding in the uterus during pregnancy.

Cellular localization of lectin-affinity in tissue sections of normal human duodenum

Peroxidase (HRP) conjugates of Arachis hypogaea agglutinin (PNA), Dolichos biflorus agglutinin (DBA), Ulex europaeus agglutinin I (UEA I) and Bandeiraea simplicifolia agglutinin I (BSA I) were used to detect the expression of carbohydrate moieties in glyco-conjugates of normal human duodenal mucosa. Lectin histology was performed on sections from paraffin embedded specimens of donor blood groups A, B, AB and 0. While PNA, DBA and UEA I staining appeared to be independent of the donor blood groups, BSA I affinity was restricted to the blood groups B and AB. Neither striated columnar cells nor goblet cells stained with PNA-HRP conjugates. Glyco-conjugates of goblet cell mucins reacted with DBA and UEA I, but staining intensities varied in crypts and villi: positive goblet cells occurred preferentially in upper parts of the crypts and in villi. Striated columnar cells also exhibited variation in staining intensities, with binding of DBA and UEA I observed in the upper half of crypts and in villi, occurring predominantly along the brush border and in apical parts of the cells. Glyco-conjugates synthesized by Brunner's gland cells possessed a great variety of lectin reactivity with the lectins employed. Within a given histological section positive gland areas with different staining intensities beside negative cell populations might reflect different functional states.

Localization of T-lymphocyte areas in human lymphoid tissues by fluorochrome-labelled Helix pomatia A haemagglutinin

Fluorochrome-labelled Helix pomatia A haemagglutinin (HP) stained T-dependent areas in cryostat tissue sections of human lymph node, tonsil, and spleen and thymocytes within thymic medulla but not within thymic cortex. Neuraminidase treatment of the tissue section was a prerequisite for the positive cell staining. The staining was cell-membrane-associated, and the histological pattern was essentially the same as that observed in parallel sections treated with monoclonal antibodies to T cells (OKT3, Leu-1). In addition, blood vessel walls and connective tissue were also stained by HP conjugates. The latter staining was independent of neuraminidase treatment, resistant to alpha-galactosidase treatment and was not blocked by pretreatment with anti-fibronectin antibody. Body types of staining reaction were specific inasmuch as unlabelled HP and the competitive sugar hapten N-acetyl-D-galactosamine blocked the reaction, Frozen, formalin-fixed tissue sections showed the same stainability and reaction pattern as unfixed sections.

Studies on carbohydrate binding to a lectin purified from Streptomyces sp

The anti-B specific lectin produced by Streptomyces sp. was shown to have two carbohydrate-binding sites with binding constants of 8.3 . 10(3) M-1 (15 degrees C) and 2.2 . 10(3) M-1 (4 degrees C) for L-rhamnose and D-galactose, respectively, calculated according to Scatchard plots. The binding of specific sugars to the lectin not only induced a peculiar ultraviolet difference spectrum showing a blue shift of tryptophan absorption, but also caused crystallization of the lectin at a concentration of 1 mg per ml or more. The solvent-perturbation studies on the lectin showed that the number of solvent-exposed tryptophan (or average extent of exposure) was two in the absence of L-rhamnose, and three in the presence of the sugar. This suggests that one tryptophan residue appears outside as the result of sugar-binding to the lectin, which is reflected by the difference spectra. Oxidation of two tryptophan residues with N-bromosuccinimide led to complete loss of carbohydrate-binding activity of the lectin, indicating that these residues are important for retaining the activity.

Composition and immunochemical properties of glycoproteins with anti-B agglutinin activity isolated from Euonymus sieboldiana seeds

Five major glycoproteins with anti-B agglutinin activity were isolated from seeds of Euonymus Sieboldiana by a procedure based on precipitation with ammonium sulphate, Sepharose 4B gel filtration, CM- and DEAE-Sepharose chromatography and Sephacryl S-200 gel filtration. The purified glycoproteins each gave a single symmetrical peak on Sephacryl S-200 gel filtration with elution volumes corresponding to molecular weights of approximately 15,000 to 130,000, each forming a single precipitin line on gel diffusion plates with anti-E. Sieboldiana antibody. These anti-B glycoproteins were rich in acidic amino acids without cysteine and methionine and contained about 8--36% carbohydrate, of which galactose, arabinose and glucose were the predominant sugars, with small amounts of glucosamine, rhamnose, fucose, xylose, mannose and ribose. The most anti-B active lectin agglutinated human B red blood cells at a concentration of 2 micrograms/ml and was strongly inhibited by melibiose. The three other lectins with anti-B agglutinin activity, however, were not inhibited by any galactose-containing glycosides.

Blood-group A and B determinants are located in different polyglycosyl peptides isolated from human erythrocytes of blood-group AB

The distribution of blood-group A and B determinants was studied by isolating blood-group ABH-active polyglycosyl peptides from delipidated human blood-group AB erythrocyte membranes after extensive digestion with pronase followed by chromatography on Bandeiraea simplicifolia I (BsI) lectin coupled to Sepharose. 20% of the polyglycosyl peptides were bound to BsI lectin. The glycopeptides bound were further fractionated using the blood-group-A-specific lectin from Vicia cracca (Vc). Approximately half of these were bound to the Vc lectin. The glycopeptides, which were bound to the Vc column, were not bound to the blood-group-B-specific isolectin from B. simplicifolia (BsIB4) whereas the Vc-unbound glycopeptides readily bound. The results indicate that in the polyglycosyl peptides isolated from AB erythrocytes A and B determinants are located in different carbohydrate chains. The polyglycosyl peptides, which did not bind to BsI lectin, were composed on the average of 30 monosaccharide units and those that bound contained on the average 55 monosaccharide units. The sugar composition was similar in both fractions except that N-acetylgalactosamine was found only in the BsI-bound glycopeptides. The substitution patterns of the monosaccharides were quite similar in both fractions except 2,3-O-linked galactose, which was enriched 7.5-fold in the BsI-bound glycopeptides and 3,6-O-linked galactose, which also enriched in the BsI-bound glycopeptides suggesting that these have a more branched structure than the BsI-unbound glycopeptides. Glycopeptides derived from bands 3 and 4.5 were prepared from A1B-blood-group erythrocyte membranes and fractionated as above. 25% of the glycopeptides were bound to BsI-lectin from both samples. 70% of the BsI-bound material from band 3 was bound to Vc lectin and 60% from band 4.5. The results indicate heterogeneity in the glycosylation of these bands.

Improved procedures for purification of the Bandeiraea simplicifolia I isolectins and Bandeiraea simplicifolia II lectin by affinity chromatography

Bandeiraea simplicifolia plant seeds contain a family of five alpha-D-galactopyranosyl-binding isolectins (BS I-A4, A3B, A2B2, AB3, B4) and N-acetyl-D-glucosamine-binding lectin (BS II). After Pi/NaCl extraction and ammonium sulfate fractionation BS II is specifically adsorbed onto p-aminobenzyl-1-thio-N-acetyl-beta-D-glucosaminide-succinylaminohexylaminyl--Sepharose-4B. The BS I isolectins pass through this column and BS II is selectively eluted by Pi/NaCl containing 2 mM N-acetyl-D-glucosamine or by 0.1 M sodium acetate buffer pH 3.6. The material not bound to the column is loaded onto p-aminophenyl-beta-D-galactopyranosyl-succinylaminohexylaminyl--Sepharose-4B. BS I-A4 is specifically eluted in a sharp peak with Pi/NaCl containing 1 mM N-acetyl-D-galactosamine. Then, BS I-A3B, A2B2, AB3 and B4 are selectively eluted, in a single peak for each isolectin. with Pi/NaCl containing 2 mM, 8 mM, 15 mM and 50 mM methyl alpha-D-galactopyranoside, respectively.