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N Gilboa-Garber

Publications and source records attributed to N Gilboa-Garber.

At least 19 recordsLinked to original sources
PubMed2006

Interactions of the fucose-specific Pseudomonas aeruginosa lectin, PA-IIL, with mammalian glycoconjugates bearing polyvalent Lewis(a) and ABH blood group glycotopes.

Pseudomonas aeruginosa Fuc > Man specific lectin, PA-IIL, is an important microbial agglutinin that might be involved in P. aeruginosa infections in humans. In order to delineate the structures of these lectin receptors, its detailed carbohydrate recognition profile was studied both by microtiter plate biotin/avidin-mediated enzyme-lectin-glycan binding assay (ELLSA) and by inhibition of the lectin-glycan interaction. Among 40 glycans tested for binding, PA-IIL reacted well with all human blood group ABH and Le(a)/Le(b) active glycoproteins (gps), but weakly or not at all with their precursor gps and N-linked gps. Among the sugar ligands tested by the inhibition assay, the Le(a) pentasaccharide lacto-N-fucopentaose II (LNFP II, Galbeta1-3[Fucalpha1-4]GlcNAcbeta1-3Galbeta1-4Glc) was the most potent one, being 10 and 38 times more active than the Le(x) pentasaccharide (LNFP III, Galbeta1-4 [Fucalpha1-3]GlcNAcbeta1-3Galbeta1-4Glc) and sialyl Le(x) (Neu5Acalpha2-3Galbeta1-4[Fucalpha1-3] GlcNAc), respectively. It was 120 times more active than Man, while Gal and GalNAc were inactive. The decreasing order of PA-IIL affinity for the oligosaccharides tested was: Le(a) pentaose > or = sialyl Le(a) tetraose > methyl alphaFuc > Fuc and Fucalpha1-2Gal (H disaccharide)>2'-fucosyllactose (H trisaccharide), Le(x) pentaose, Le(b) hexaose (LNDFH I) and gluco-analogue of Le(y) tetraose (LDFT)>H type I determinant (LNFP I)>Le(x) trisaccharide (Galbeta1-4[Fucalpha1-3]GlcNAc) > sialyl Le(x) trisaccharide >> Man >>> Gal, GalNAc, and Glc (inactive). The results presented here, in accordance with the crystal 3D structural data, imply that the combining site of PA-IIL is a small cavity-type best fitting Fucalpha1- with a specific shallow groove subsite for the remainder part of the Le(a) saccharides, and that polyvalent glycotopes enhance the reactivity. The Fuc > Man Ralstonia solanacearum lectin RSL, which resembles PA-IIL in sugar specificity, differs from it in it's better fit to the B and A followed by H oligosaccharides vs. Fuc, whereas, the second R. solanacearum lectin RS-IIL (the structural homologue of PA-IIL) binds Man > Fuc. These results provide a valuable information on PA-IIL interactions with mammalian glycoforms and the possible spectrum of attachment sites for the homing of this aggressive bacterium onto the target molecules. Such information might be useful for the antiadhesive therapy of P. aeruginosa infections.

ABO Blood-Group System↗
PubMed2006

H-deficient Bombay and para-Bombay red blood cells are most strongly agglutinated by the galactophilic lectins of Aplysia and Pseudomonas aeruginosa that detect I and P1 antigens.

The galactophilic lectins Aplysia gonad lectin (AGL) and Pseudomonas aeruginosa lectin (PA-IL), which detect human I and P1 RBC antigens, were examined for hemagglutination of H+ (group O and B) and H-deficient (Bombay and para-Bombay phenotype) RBCs. The results were compared with those obtained using two other galactophilic lectins, Maclura pomifera lectin (MPL) and Arachis hypogaea (peanut) agglutinin (PNA), which share T-antigen affinity, and two fucose-binding H-specific lectins, Ulex europaeus (UEA-I) and Pseudomonas aeruginosa lectin (PA-IIL), as well as with those achieved with anti-I serum. The results revealed that, in contrast to UEA-I and PA-IIL, which preferentially agglutinated H+ RBCs, and to MPL and PNA, which similarly agglutinated all examined RBCs, AGL, PA-IL, and the anti-I serum agglutinated the H-deficient RBCs more strongly than did the H+ RBCs. These findings could be attributed to increased levels of I and P1 antigens on those RBCs resulting from the use of the free common H-type 2 precursor for their synthesis. Since both PA-IL and PA-IIL are regarded as potential pathogen adhesins, it would be interesting to statistically compare the sensitivities of individuals of H+ and H-deficient RBC populations to P. aeruginosa infections.

ABO Blood-Group System↗
PubMed2003

Pseudomonas aeruginosa lectin PA-IIL as a powerful probe for human and bovine milk analysis.

Milk composition exhibits species-specific differences depending on genetic, evolutionary, and environmental factors. In addition, commercial milk preparations are also changed by industrial manipulations, including severe heat processing. Cow milk, used as human food, provides important nutrients but lacks some essential components that are present in raw human milk. The present study, which was aimed at comparing infant breastfeeding to cow-based formula nourishment, shows major differences between the human and the commercial cow milk glycans detectable by the lectins PA-IL (galactose-binding) and PA-IIL (fucose and mannose-binding) isolated from the cells of human pathogen Pseudomonas aeruginosa. More than 40 human milk samples, several cow milks, and bovine milk-based infant formulas, were examined using these two lectins. For purposes of comparison, the plant lectins Concanavalin A (Con A), which binds mannose, and Ulex europaeus 1st lectin (UEA-I), which binds fucose, were also used. The most prominent difference was revealed using PA-IIL, which displayed a unique high sensitivity to the human milk fucosylated compounds. PA-IL and UEA-I also exhibited preferential sensitivity to the human milk but considerably lower than that of PA-IIL. Con A was inhibited by human and the other milk preparations examined to the same extent. These findings indicate the superb applicability of PA-IIL for rapid and reliable comparative investigation of milk glycans from human and cow, indicating which glycans could be added to infant formulas in order to enrich them, as well as for verification and quality control of otherwise improved bovine milk-based infant formulas.

Adhesins, Bacterial↗
PubMed2001

Binding properties and applications of Aplysia gonad lectin.

Adult Aplysia gonad contains high levels of a galactophilic lectin (MW around 65 kDa; composed of 2 subunits of apparent single species). It binds galactose and various alpha/beta-galactosides (but not N-acetylgalactosamine), in addition to an outstanding high affinity for galacturonic acid. This lectin is relatively resistant to heating up to 70 degrees C and to alkaline pH, but sensitive to proteolysis and low pH. It resembles galectins in binding to poly LacNAc (preferentially branched) complexes at low temperatures (0 degrees-4 degrees C) more avidly than at room temperature or at 37 degrees C, but differs from them in being Ca(2+)-dependent. It agglutinates papain/sialidase-treated erythrocytes more strongly than untreated cells and stimulates mitosis in peripheral human lymphocytes (inducing IL-2 formation). This lectin also enhances neurite outgrowth and increases their viability, while suppressing cell tumorigenicity. It is useful for histochemical/ cytochemical studies of galacturonic acid in plant tissues and fungi and for the study of cell surface composition of various prokaryotic (including halophilic Archaea) and eukaryotic cells and for their typing. It is useful as a reagent for I-antigen detection in adult human erythrocytes (anti-I), exhibiting strongest agglutination of O(h) Bombay-type erythrocytes and also exhibits sensitivity to the T antigen. It binds galactosylated molecules in human body fluids (shown by hemagglutination--inhibition tests), including saliva, seminal fluid and milk (detecting individual divergence) and in fowl egg albumens (exhibiting highest affinity for that of pigeon). Therefore, it might be valuable as a probe and fishhook for fishing compounds exhibiting anti-bacterial/neoplastic cell adhesion activities.

Animals↗
PubMed2001

Interaction of Pseudomonas aeruginosa galactophilic lectin PA-IL with pigeon egg white glycoproteins.

Pseudomonas aeruginosa produces a galactophilic lectin, PA-IL, that resembles P-fimbrial adhesins of uropathogenic Escherichia coli strains in binding to human P blood group antigens. We examined, in the present study, its interaction with pigeon egg white glycoproteins carrying N-glycans with terminal Galalpha1-4Gal which inhibit the adhesion of P-fimbriae. For comparison, the lectin concanavalin A (Con A) and additional avian egg whites (of hen and quail) were also examined. The results obtained in both hemagglutination inhibition and Western blot analyses showed that PA-IL, unlike Con A, preferentially reacted with the pigeon egg white glycoproteins. These results, which confirmed PA-IL similarity in sugar specificity to E. coli P-fimbriae, demonstrated the advantage of this purified lectin for representing P-type and additional galactophilic microbial adhesins unavailable in purified stable form, in Western blot analyses.

Adhesins, Bacterial↗
PubMed2001

Usage of Aplysia lectin interactions with T antigen and poly-N-acetyllactosamine for screening of E. coli strains which bear glycoforms cross-reacting with cancer-associated antigens.

Aplysia gonad lectin (AGL), which strongly agglutinates cancer cells, was found, in the present study, to bind to erythrocyte T antigen, in addition to its affinity to Ii system antigens. These antigens were reported to be overexpressed and to contribute to tumor progression and invasion. In healthy human sera, there are antibodies against them, stimulated by the normal intestinal microflora, which bear similar glycoforms. Since the levels of these antibodies were reported to be lower in most cancer patients' sera, we have examined the applicability of AGL to isolation of enteric commensal Escherichia coli strains which bear glycoforms cross-reacting with the cancer-associated antigens. Among 30 E. coli isolates examined, two were agglutinated by AGL. One of them was also agglutinated by certain related galactophilic lectins, which bind to the T and Tn antigens. The agglutination of the two bacteria by healthy human sera, as a group, was stronger than that displayed by the cancer patients' sera. These results indicate that AGL might be useful for identification of the desired bacteria, which could potentially serve for cancer diagnosis and therapy.

Agglutination Tests↗
PubMed2001

Interactions of Pseudomonas aeruginosa PA-IIL lectin with quail egg white glycoproteins.

Pseudomonas aeruginosa produces several lectins, including the galactophilic PA-IL and the fucose- and mannose-binding PA-IIL. The great advantage of these two lectins is their stability in purified preparations. Following observations that pigeon egg white blocks Escherichia coli P-fimbriae and PA-IL, we examined the interactions of diverse avian egg white components with PA-IIL. This lectin may represent both mannose- and fucose-specific microbial adhesins. For comparison, Con A (which also binds mannose) and Ulex europaeus lectin (UEA-I, which binds fucose) were analyzed in parallel. The lectin interactions with chicken, quail, and pigeon egg whites and several purified chicken egg white glycoproteins were examined by a hemagglutination inhibition test and Western blotting. Both analyses showed that like Con A and unlike UEA-I, which was not sensitive to any of these three egg whites, PA-IIL most strongly reacted with the quail egg white. However, in contrast with Con A, its interactions with the chicken egg white components, excluding avidin, were very poor. The results of this study might indicate the possibility that some of the egg white components that interacted with the above two mannose-binding lectins (exhibiting individual heterogeneity) might be associated with the innate immunity against mannose-specific microbial or viral adhesion during the fowl embryonic period.

Adhesins, Bacterial↗
PubMed2000

Defining the carbohydrate specificities of aplysia gonad lectin exhibiting a peculiar D-galacturonic acid affinity.

Aplysia gonad lectin (AGL), which has been shown to stimulate mitogenesis in human peripheral lymphocytes, to suppress tumor cells, and to induce neurite outgrowth and improve cell viability in cultured Aplysia neurons, exhibits a peculiar galacturonic acid/galactose specificity. The carbohydrate binding site of this lectin was characterized by enzyme-linked lectino-sorbent assay and by inhibition of AGL-glycan interactions. Examination of the lectin binding with 34 glycans revealed that it reacted strongly with the following glycoforms: most human blood group precursor (equivalent) glycoproteins (gps), two Galalpha1-->4Gal-containing gps, and two d-galacturonic acid (GalUA)-containing polysaccharides (pectins from apple and citrus fruits), but poorly with most human blood group A and H active and sialylated gps. Among the GalUA and mammalian saccharides tested for inhibition of AGL-glycan binding, GalUA mono- to trisaccharides were the most potent ones. They were 8.5 x 10(4) times more active than Gal and about 1.5 x 10(3) more active than the human blood group P(k) active disaccharide (E, Galalpha1-->4Gal). This disaccharide was 6, 28, and 120 times more efficient than Galbeta1-->3GlcNAc(I), Galbeta1-->3GalNAc(T), and Galbeta1--> 4GlcNAc (II), respectively, and 35 and 80 times more active than melibiose (Galalpha1-->6Glc) and human blood group B active disaccharide (Galalpha1-->3Gal), respectively, showing that the decreasing order of the lectin affinity toward alpha-anomers of Gal is alpha1-->4 > alpha1-->6 > alpha1-->3. From the data provided, the carbohydrate specificity of AGL can be defined as GalUAalpha1-->4 trisaccharides to mono GalUA > branched or cluster forms of E, I, and II monomeric E, I, and II, whereas GalNAc is inactive.

Animals↗
PubMed2000

Identification and characterization of pseudomonas aeruginosa PA-IIL lectin gene and protein compared to PA-IL.

Using the 33 N-terminal amino acids of the fucose/mannose binding lectin PA-IIL of Pseudomonas aeruginosa ATCC 33347 in a tblastn search of P. aeruginos PAOI genomic sequence in GenBank revealed a single open reading frame encoding a 114-amino acid protein (excluding initiator methionine) perfectly matching that amino acid sequence. Following its stop codon there is a GC-rich sequence having a perfect dyad symmetry promoting formation of a hairpin loop structure, potentially enabling rho-independent transcription termination. Upstream of the putative ribosomal binding site there are sequences resembling Vibrio fischeri luxIbox. consistent with autoinduction of this gene, The predicted PA-IIL molecular mass, confirmed by mass spectrometry, is 11,732 Da. Its pI is 3.88. The C-terminal domain is particularly hydrophobic, implying possible embedding in the cell membrane. PA-IIL is similar to P. aeruginosa PA-IL lectin in some amino acids and potential glycosylation sites but lacks cysteine, methionine and histidine. Despite their relations in functions and regulation.,their genes are widely separated (by about 867.5 kb).

Adhesins, Bacterial↗
PubMed1999

Cold-induced augmentation of I blood group antigen interactions with galactophilic lectins.

The I antigen appears on human cells in the postnatal period, by addition of N-acetyllactosamine (beta 1-6) branching to the fetal i antigen structure, which is specified by linear oligo N-acetyllactosamine (beta 1-3) chain. Concurrently with the I antigen appearance on adult human erythrocytes most human sera exhibit low levels of anti-I agglutinins. These antibodies induce hemagglutination mainly at low temperatures (4 degrees C) and scantly at body temperature. Therefore they were named "cold agglutinins". We have used these antibodies and several hemagglutinating galactophilic animal, plant, and microbial lectins that also react with the I antigen, to study whether the cold-favored agglutination of the I antigen-bearing cells is a peculiar property of the anti-I antibodies or a special trait of that antigen. It has been found that the interactions of all of the examined lectins, irrespective of their source, with the adult human erythrocytes significantly increased at 4 degrees C, in contrast to those of the same cells with diverse I-insensitive antibodies and lectins, which were significantly higher at room temperature.

Adult↗
PubMed1999

A comparison of the Aplysia lectin anti-I specificity with human anti-I and several other I-detecting lectins.

BACKGROUND: Lectins displaying blood group specificity are important for blood group typing and antigen recognition. Their use in blood banks is especially widespread in situations where there is a shortage of specific antisera. This report describes the efficiency of Aplysia gonad lectin as a reliable reagent for the detection of I antigen, which is common on adult human cells but reduced in fetal, newborn, and rare adult red cells. STUDY DESIGN AND METHODS: The selective hemagglutinating activity of the Aplysia lectin was compared with that of human anti-I and several I-reactive lectins, including two plant lectins, one galactophilic microbial lectin, and bovine spleen galectin. RESULTS: The comparison has revealed that Aplysia gonad lectin, like human anti-I, strongly agglutinates and adsorbs to adult I-positive red cells, differentiating between them and fetal or rare I-negative adult red cells (although with less of a difference). In contrast to the plant and microbial lectins examined, its I-affinity does not depend on the presence of ABH or P system antigens and it clearly detects higher I antigen expression in Oh red cells. The hemagglutinating activity of Aplysia lectin as that of all the I-detecting proteins is enhanced at 4 degrees C, but unlike the human anti-I Aplysia lectin-induced hemagglutination is stable at room temperature. CONCLUSIONS: The Aplysia lectin is a reliable anti-I reagent, which strongly agglutinates I-positive adult human red cells irrespective of their ABH or P system antigens. This lectin is usable at room temperature.

Adult↗
PubMed1999

The hemagglutinating activities of Pseudomonas aeruginosa lectins PA-IL and PA-IIL exhibit opposite temperature profiles due to different receptor types.

The two Pseudomonas aeruginosa lectins PA-IL and PA-IIL, which are very similar in subunit size, composition and properties, but differ in carbohydrate specificity, were shown to exhibit opposite temperature profiles in hemagglutination tests. The galactophilic PA-IL, which interacts with the erythrocyte I antigen (together with B or P system antigens), resembles Ii system-specific 'cold hemagglutinins' (including antibodies and lectins of animals and plants) in low (4 degrees C) temperature optimum, while the hemagglutination by the fucose- and mannose-binding PA-IIL (like that of antibodies and lectins which do not bind to these antigens) increases on raising the temperature from 4 to 37 degrees C and even to 42 degrees C. The preferential production of both P. aeruginosa lectins at 28 degrees C and their much stronger interaction with enzyme (protease or sialidase)-damaged cells, as well as the lower temperature optimum (4 degrees C) of PA-IL-binding to the host cells, may be associated with the saprophytic rather than parasitic designation of this bacterium.

Adhesins, Bacterial↗
PubMed1998

Typing of halophilic Archaea and characterization of their cell surface carbohydrates by use of lectins.

Lectins are important tools for cell typing and for the study of cell surface components. They have been widely used for the analysis of carbohydrates on the surface of many eukaryotic and prokaryotic cells, but they have not yet been exploited in the study of the halophilic Archaea (family Halobacteriaceae), because of the high salinity required for the structural integrity of these microorganisms. We have defined the salt concentration threshold high enough for survival of the Archaea, but sufficiently low for lectins to bind to them. Under these conditions we studied the interactions of a series of lectins, exhibiting different sugar specificities, with diverse halophilic Archaea. Concanavalin A was the most reactive by virtue of its glucose (and mannose) binding. The other lectins varied in their interactions. The results indicate that lectins might be useful probes for both archaeal typing and analysis of their cell surface carbohydrates.

Bacterial Typing Techniques↗
PubMed1998

Structural specificity of serotonin effect on human erythrocyte fragility.

Serotonin, a neurotransmitter and vasoconstrictor, affects various cell properties. We have analyzed the importance of its structural components for its extensive effect on human erythrocyte fragility, using its O- and N-linked derivatives and related compounds. The results presented in this communication indicate that the amino group, free of adjacent negative charges, and the hydroxyl group are indispensable for the serotonin-induced increase in red blood cell fragility.

Cell Membrane Permeability↗
PubMed1998

Studies on the binding site of the galactose-specific agglutinin PA-IL from Pseudomonas aeruginosa.

The binding properties of Pseudomonas aeruginosa agglutinin-I (PA-IL) with glycoproteins (gps) and polysaccharides were studied by both the biotin/avidin-mediated microtiter plate lectin-binding assay and the inhibition of agglutinin-glycan interaction with sugar ligands. Among 36 glycans tested for binding, PA-IL reacted best with two glycoproteins containing Galalpha1-->4Gal determinants and a human blood group ABO precursor equivalent gp, but this lectin reacted weakly or not at all with A and H active gps or sialylated gps. Among the mammalian disaccharides tested by the inhibition assay, the human blood group Pkactive Galalpha1-->4Gal, was the best. It was 7.4-fold less active than melibiose (Galalpha1-->6Glc). PA-IL has a preference for the alpha-anomer in decreasing order as follows: Galalpha1-->6 >Galalpha1-->4 >Galalpha1-->3. Of the monosaccharides studied, the phenylbeta derivatives of Gal were much better inhibitors than the methylbeta derivative, while only an insignificant difference was found between the Galalpha anomer of methyl- and p -NO2-phenyl derivatives. From these results, it can be concluded that the combining size of the agglutinin is as large as a disaccharide of the alpha-anomer of Gal at nonreducing end and most complementary to Galalpha1-->6Glc. As for the combining site of PA-IL toward the beta-anomer, the size is assumed to be less than that of Gal; carbon-6 in the pyranose form is essential, and hydrophobic interaction is important for binding.

ABO Blood-Group System↗
PubMed1996

Differentiation between human red cells of Pk and p blood types using Pseudomonas aeruginosa PA-I lectin.

BACKGROUND: The red cells of almost all human beings bear P antigen. Type P1 cells (around 75% of the population) contain P1 antigen in addition to P, and type P2 cells (around 25% of the population) contain only P. The red cells of only a few individuals are devoid of P: these cells may be of either Pk-positive (P1k and P2k[Pk]) or p type (the latter lack all the above-described antigens of the P system). Differentiation between them is of clinical importance, but there is a shortage of specific reagents. This article offers reliable means for differentiation. STUDY DESIGN AND METHODS: Agglutination of washed, papain-treated red cells of all the P types by PA-1 and soybean lectins and adsorption of the lectins onto the red cells were examined. RESULTS: PA-1 strongly agglutinated papain-treated red cells. Examination of its interactions with red cells having different P system antigens revealed that Pk (both P1k and P2k) red cells of O, A, and B blood types were agglutinated significantly faster than p red cells. The agglutination intensities of Pk red cells of types O and A (most people) was considerably stronger than those of p red cells. P1 and P2 type red cell agglutination was intermediate (P1>P2). Adsorption tests with all the red cells, exhibited the same order of PA-1 affinities for the P system blood types: Pk>P1,>P2>p. The soybean lectin exhibited opposite behavior (p>P2>P1>Pl). CONCLUSION: The galactose-binding lectins PA-1 and soybean may facilitate the determination of Pk and p red cells.

ABO Blood-Group System↗
PubMed1995

Isolation and characterization of a Pseudomonas aeruginosa genomic DNA sequence, encoding a putative DNA helicase belonging to superfamily I.

The isolation and characterization of a 2,122 bp DNA fragment from a Pseudomonas aeruginosa genomic library containing a 1,495 bp open reading frame (ORF) encoding a putative DNA helicase is described. The deduced amino acid (498 residues) sequence derived from this ORF, exhibited a high degree of homology to the rep and uvrD helicases of Escherichia coli (55 and 38% identities, respectively), and to those of Staphylococcus aureus and Haemophilus influenzae (43 and 39% identities, respectively), all of them belonging to superfamily I.

Amino Acid Sequence↗