Rat lung 29 kD beta-galactoside-binding lectin is secreted by bronchiolar Clara cells into airways

We isolated a mixture of beta-galactoside-binding lectins from rat lung and raised polyclonal antibody against 14 kD lectin purified from the mixture of lectins. Immunoblotting of the mixture of lectins, which was separated with SDS-PAGE under reducing condition and transferred onto a NC paper, showed that the antibody reacted with two bands at 14 and 29 kD, indicating that these two lectins have common antigenic determinants(s). Immunohistochemically, the antibody recognized only bronchiolar Clara cells with intense immunofluorescence in their apical cytoplasmic protrusions where the secretory granules of the cells are known to be stored. Thus, to determine if the lectin(s) might be secreted into airways, we next raised antibody against airway secretions free from serum as well as surfactant proteins. By immunoblot analysis, the resulting antibody stained 29,45 and 55 kD bands, but not 14 kD band, on a NC paper transferred with the mixture of lectins. These findings suggest that at least 29 kD lung lectin is located in bronchiolar Clara cells and secreted by these cells into airways.

Multiple soluble vertebrate galactoside-binding lectins

All vertebrates synthesize soluble galactoside-binding lectins. Many are expressed at high levels in the embryo and at lower levels in the adult, whereas others show an inverse pattern of expression. Most lectins tend to be concentrated in one or a number of specific cell types. In the past few years, the multiplicity of these lectins has become more apparent. For example, in Xenopus laevis 3 galactoside-binding lectins, 2 with a preference for alpha-galactosides, have been purified and partially characterized. They have subunit molecular weights ranging from 16,000 to 69,000. More detailed studies have been done in mammals. For example, rat lung contains 3 soluble beta-galactoside-binding lectins, RL-14.5, RL-18 and RL-29, with subunit molecular weights, respectively, of 14,500, 18,000 and 29,000. A notable feature of these lectins is that, although they all bind lactose about equally well, their carbohydrate-binding sites are actually quite different, as shown by competitive binding studies with a range of complex mammalian glycoconjugates. Human lung also contains several beta-galactoside-binding lectins, including HL-14, HL-22 and HL-29 with subunit molecular weights, respectively, of 14,000, 22,000 and 29,000. They too show significant differences in their carbohydrate-binding sites when analyzed with naturally occurring mammalian glycoconjugates. Sequencing of purified lectins and cDNA clones indicates that at least 4 distinct genes code for what appears to be a family of HL-14. Heterogeneity is also indicated from isoelectric focusing studies which resolve at least 6 acidic forms of HL-14 and 5 acidic forms of HL-29.(ABSTRACT TRUNCATED AT 250 WORDS)

Purification and characterization of CS2, a sialic acid-specific haemagglutinin of enterotoxigenic Escherichia coli

CS2 fimbriae of enterotoxigenic Escherichia coli were purified and characterized. The surface haemagglutinins (fimbriae) were detached by sonication from a strain producing only the CS2 fimbriae. Isolation was carried out by gel filtration on a Sepharose 4B column. After depolymerization, the fimbriae subunits were purified on a Sephacryl S-300 column in 8.0 M-guanidinium chloride. From 1 litre of medium, 4-6 mg of purified fimbriae was obtained. We found that CS2 fimbriae were completely dissociated by saturated guanidinium chloride into subunits with a molecular mass of 16.5 kDa. CS2 fimbriae was sialic acid-specific, since sialic acids were the most potent inhibitors, and neuraminidase treatment of erythrocytes abolished haemagglutination. Both fimbriae and fimbrial subunits were found to bind to bovine erythrocytes. The binding of subunits to erythrocytes could be inhibited with low concentrations of sialyl-lactose.

Complete amino acid sequence of a beta-galactoside-binding lectin from human placenta

The complete amino acid sequence of a beta-galactoside-binding lectin from human placenta was determined at protein level. The lectin consists of 134 amino acids and its N-terminal alanine is blocked with acetate. The lectin shows about 50% similarity with chick 14K lectin, which was the first vertebrate beta-galactoside-binding lectin completely sequenced. Only 14 residues proved to be different from those of rat lung lectin, the sole mammalian lectin of which the complete sequence has been reported.

The purification and characterization of an acellular pertussis vaccine

An acellular pertussis vaccine manufactured by Biken was investigated for purity, potency and toxicity. The vaccine was composed of almost equal proportions of pertussis toxin (PT) and filamentous hemagglutinin (FHA). The purity of the vaccine was 97-99%. The protective effects of component vaccines containing various ratios of PT and FHA were tested and it was found that the ratio of 1:1 provided the most effective vaccine.

Sequence of a full-length cDNA for rat lung beta-galactoside-binding protein: primary and secondary structure of the lectin

A full-length cDNA for rat lung beta-galactoside lectin (subunit Mr approximately 14,000, lectin 14K) was cloned and the nucleotide sequence determined. The deduced amino acid sequence agrees with the amino acid composition and direct amino acid sequence analysis of purified rat lung lectin peptides. We found that the amino-terminal alanine is blocked with an acetyl group. Comparison of the amino acid sequence with other proteins shows a high degree of homology only with other vertebrate lectin sequences, supporting the suggestion that these lectins may constitute a unique class of vertebrate proteins. The amino acid composition and sequence of lectin peptides, the sequence of lectin cDNA, and isoelectric focusing of purified lectin indicate that rat lung lectin 14K is composed predominantly of a single protein. In addition, rat uterus lectin 14K was found to be the same protein as that present in lung. We characterized the secondary and tertiary structure of rat lung lectin 14K by circular dichroism, by analytical ultracentrifugation, and by computer analysis of its primary structure. Results of these experiments suggest that lectin 14K is primarily a hydrophilic protein with an asymmetric, elongated structure consisting of approximately equal amounts of alpha helix, beta sheet, beta turn, and random coil. We found that Cys-2 and Cys-130 react most rapidly with iodoacetamide; one or both of these residues may be primarily responsible for the thiol requirement of lectin activity.

Partial purification of a bacterial lectinlike substance from Eikenella corrodens

A bacterial lectinlike substance, which is considered to participate in the adherence of Eikenella corrodens to various host cells, was purified from E. corrodens cells. The substance was extracted in 1% Triton X-100 with sonication from the cell envelope of E. corrodens 1073 and partially purified by galactosamine affinity chromatography and gel filtration chromatography based on its hemagglutination (HA) activity. The lectinlike substance was purified about 256-fold as evaluated by its specific HA activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the partially purified lectinlike substance (PPL) produced a single protein band of large molecular weight when it was applied to the gel without the addition of beta-mercaptoethanol and heating. Chemical analysis showed that PPL contained 14.4 micrograms of hexose per 100 micrograms of protein and that it did not contain muramic acid, glucosamine, or 2,6-diaminopimelic acid, which are characteristic of peptidoglycans. The HA activity of PPL was inhibited by EDTA but restored by adding Ca2+. The HA activity was remarkably inhibited by sugars containing N-acetyl-D-galactosamine and D-galactose. These results indicate that the lectinlike substance on the E. corrodens cells is an essential factor for the adherence to host cells.

Comparative studies of the haemagglutination of adult and umbilical cord erythrocytes by animal lectins

1. The sugar specificities of four lactose-binding lectins were studied through the agglutination of adult and/or umbilical cord human erythrocytes (AHRBC and/or CHRBC). 2. Rana catesbeiana egg lectin specifically agglutinated both intact blood group A-AHRBC and intact blood group A-CHRBC. 3. Rana catesbeiana liver lectin agglutinated intact A-AHRBC much more strongly than intact A-CHRBC. 4. Xenopus laevis skin lectin nonspecifically agglutinated AHRBC and CHRBC. 5. Plecoglossus altivelis egg lectin specifically agglutinated intact B-AHRBC, but weakly agglutinated intact B-CHRBC. 6. Comparative studies of lectin-induced AHRBC or CHRBC agglutination clarified the sugar-binding specificities of these lectins.

Purification and some characteristics of a beta-galactoside binding soluble lectin from amphibian ovary

Soluble extracts of Bufo ovaries agglutinate sialidase-treated rabbit erythrocytes. Unlike other amphibian lectins this agglutination activity does not require the presence of calcium ions. It is specifically inhibited by D-galactose and its derivatives. Thiodi-D-galactoside is the most potent saccharide inhibitor followed by lactose and methyl-beta-D-galactoside, respectively. D-Fucose, D-glucose and D-mannose do not inhibit the activity at concentrations at or above 100 mM. The lectin has been purified 500-fold to apparent homogeneity from the ovaries by salt extraction and affinity chromatography on lactose-aminophenyl-agarose, with a yield of about 0.2%. The molecular mass determined by gel filtration under native conditions was 30 kDa; polyacrylamide gel electrophoresis in SDS gave a molecular mass of 15 kDa, suggesting that the lectin is a dimer. The lectin has an isoelectric point of 40 and contains a high proportion of acidic amino acids.

Isolation of the galactose-binding lectin that mediates the in vitro adherence of Entamoeba histolytica

Entamoeba histolytica adheres to human colonic mucus, colonic epithelial cells, and other target cells via a galactose (Gal) or N-acetyl-D-galactosamine (GalNAc) inhibitable surface lectin. Blockade of this adherence lectin with Gal or GalNAc in vitro prevents amebic killing of target cells. We have identified and purified the adherence lectin by two methods: affinity columns derivatized with galactose monomers or galactose terminal glycoproteins, and affinity columns and immunoblots prepared with monoclonal antibodies that inhibit amebic adherence. By both methods the adherence lectin was identified as a 170-kD secreted and membrane-bound amebic protein. The surface location of the lectin was confirmed by indirect immunofluorescence. Purified lectin competitively inhibited amebic adherence to target cells by binding to receptors on the target Chinese hamster ovary cells in a Gal-inhibitable manner.

Studies on cellular adhesion of Xenopus laevis melanophores: modulation of cell-cell and cell-substratum adhesion in vitro by endogenous Xenopus galactoside-binding lectin

We have investigated cell-cell and cell-substratum adhesion of Xenopus laevis neural crest cells at various stages of melanophore differentiation. Single-cell suspensions were obtained by trypsinization and aggregated in a cell-cell adhesion assay. Unpigmented cells did not adhere while the rate of adhesion of melanophores correlated with the degree of melanization. Melanophore cell-cell adhesion decreased significantly in the presence of beta-galactosidase, which suggests that cell-surface galactose is involved. Beta-galactoside-binding lectin has been isolated and purified from embryos at the stage of neural crest migration. When added to aggregating cells smaller, looser clusters formed compared to controls. When lectin was added to cells in stationary culture to test cell-substratum adhesion, melanophores spread more smoothly and formed more regular spacing patterns. These results suggest that this lectin can modulate receptors used in cell-cell and cell-substratum adhesion of melanophores.

Purification and characterization of a beta-galactoside-binding soluble lectin from rat and bovine brain

A beta-galactoside-binding activity has been detected in mammalian brain extracts using a hemagglutination test and a nerve cell aggregation assay. Inhibition studies suggested the involvement of lectin-carbohydrate interactions in these processes. In an attempt to explore further the biological role of brain lectins, the beta-galactoside-binding activity has been purified to apparent homogeneity from bovine and rat brain by salt extraction of the brain tissue and affinity chromatography on asialofetuin-agarose. The molecular weights determined by gel filtration, under native conditions on Ultrogel AcA-34, were 30,000 for the bovine brain lectin and 32,000 for the rat brain lectin; polyacrylamide gel electrophoresis in SDS gave molecular weights of 15,000 and 16,000, respectively, suggesting that the two brain lectins are dimers. Both lectins have an isoelectric point of 3.9. Amino acid composition data indicate that both lectins contain high proportions of glycine and acidic amino acids. The lectins are specific for beta-D-galactosides and related sugars and the configuration of carbon atoms 1, 2 and 4 seems of primary importance. Moreover, the nerve cell aggregation-promoting activity of the purified lectin is 300-fold that of the crude extracts.

Comparative analysis of galactoside-binding lectins isolated from mammalian spleens

Galactoside-inhibitable lectins have been isolated from rabbit, rat, mouse, pig, lamb, calf, and human spleens. Native molecular mass, subunit structure, pI, and hemagglutinating activity have been compared for these lectins. The yields of lectin varied from 1.8 mg/kg for rabbit spleen to 79 mg/kg for lamb spleen. Pig, lamb, calf, and human spleen lectins yielded single protein peaks when subjected to Superose 12 fast-protein liquid chromatography. The apparent molecular mass for these lectins was 33-34 kDa. In contrast, rat and mouse spleen lectin preparations were separated into three components ranging from 8.4 to 34 kDa. Superose 12 chromatography of rabbit spleen lectin revealed the presence of at least six components. Gradient slab gel sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed the presence of single polypeptides for pig, calf, lamb, and human lectins corresponding to a molecular mass of 14-14.5 kDa. Multiple polypeptides were detected for the mouse, rat, and rabbit lectins. The molecular mass of the major polypeptides were 15, 15, and 17 kDa for rat, mouse, and rabbit, respectively. The presence of isolectins in all preparations was shown by isoelectric focusing. The major isolectins were acidic proteins with pI 4.38-4.80. Hemagglutination and hemagglutination inhibition assays demonstrated similarities as well as differences among the lectin preparations. Hemagglutinating activity could not be demonstrated in rabbit spleen extracts nor for isolated putative lectin. Human buffy coat cells were reversibly agglutinated by calf and human spleen lectins, demonstrating the presence of leucocyte cell surface lectin receptors.

Amino acid sequence of beta-galactoside-binding bovine heart lectin. Member of a novel class of vertebrate proteins

A variety of animal tissues contain beta-galactoside-binding lectins with molecular masses in the range 13-17 kDa. There is evidence that these lectins may constitute a new protein family although their function in vivo is not yet clear. In this work the major part of the amino acid sequence of the 13 kDa lectin from bovine heart muscle has been determined. Comparison of this sequence with the cDNA-deduced sequence published for the chick embryo skin lectin showed 58% homology. Comparison of the bovine lectin sequence with partial sequences from two cDNA clones from a human hepatoma library and partial amino acid sequences of human lung lectin showed 70, 40 and 85% homology, respectively. The sequences of these vertebrate lectins are thus clearly related, supporting earlier results of immunological cross-reactivity within this group of proteins. Computer searching of protein sequence databases did not detect significant homologies between the bovine lectin sequence and other known proteins.

Carbohydrate-binding protein 35: molecular cloning and expression of a recombinant polypeptide with lectin activity in Escherichia coli

Affinity-purified antibodies directed against carbohydrate-binding protein 35 (CBP35), a galactose-specific lectin, were used to screen a lambda gt 11 expression library derived from mRNA of 3T3 fibroblasts. This screening yielded several putative clones containing cDNA for CBP35, one of which was characterized in terms of its expression of a fusion protein containing beta-galactosidase and CBP35 sequences. Limited proteolysis of lysates containing the fusion protein, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with anti-CBP35, yielded a peptide mapping pattern comparable to that obtained from parallel treatment of authentic CBP35. Such a limited proteolysis followed by affinity chromatography on a Sepharose column coupled with galactose also yielded a 30-kDa polypeptide that exhibited carbohydrate-binding activity. This polypeptide can be immunoblotted with anti-CBP35, but not with antibodies directed against beta-galactosidase. These results indicate that we have identified a cDNA clone for CBP35 that yields a recombinant polypeptide with lectin activity produced in Escherichia coli. Using this cDNA clone as a probe, Northern-blot analysis showed an increased expression of the CBP35 gene when quiescent 3T3 cells were activated by the addition of serum growth factors.

Purification and properties of hemagglutinin from culture supernatant of Bacteroides gingivalis

The hemagglutinating factor (hemagglutinin) of Bacteroides gingivalis was prepared from the supernatant of a 5-day diffusate broth culture by ammonium sulfate precipitation and column chromatography with a hydrophobic column of Phenyl-Sepharose CL-4B, DEAE-Sephadex A-50, and Sephadex G-100 gel filtration. The hemagglutinating activity of the preparation was 53.3 times higher than that of ammonium sulfate precipitate. In electron microphotographs, hemagglutinin appears to have a vesicle or tubelike structure. The hemagglutinating activity of intact cells was completely destroyed by heating at 100 degrees C for 10 min, but the activity of extracted hemagglutinin was heat stable. The activity of hemagglutinin was inhibited by L-arginine and L-lysine and partially inhibited by phospholipase D, but it was not affected by proteolytic enzymes, neuraminidase, hyaluronidase, lipase, phospholipase A and C, or sugars. The B. gingivalis hemagglutinin appeared to be comprised mainly of a 40,000-molecular-weight material. The Fab fragment of immunoglobulin G prepared from rabbit antiserum to whole cells of B. gingivalis and monoclonal antibody against the hemagglutinin bound to the cell surface and inhibited the hemagglutinating activity of both the cells and the purified hemagglutinin.

Identification of two new hemagglutinins of Escherichia coli, N-acetyl-D-glucosamine-specific fimbriae and a blood group M-specific agglutinin, by cloning the corresponding genes in Escherichia coli K-12

Genes encoding the Escherichia coli IH11165 hemagglutinins with specificity for terminal N-acetyl-D-glucosamine and blood group M antigen, respectively, were cloned by a cosmid cloning procedure. A 22-kilobase-pair subclone expressed both hemagglutination specificities in the nonhemagglutinating E. coli HB101 recipient strain. Derivatives obtained by insertion and deletion mutagenesis expressed either one of the two hemagglutination specificities. Both agglutinins were purified; the agglutinin recognizing terminal N-acetyl-D-glucosamine was associated with a new type of fimbria (G fimbria) with an apparent subunit molecular mass of 19.5 kilodaltons, whereas the blood group M agglutinin (M agglutinin) was nonfimbrial and had an apparent subunit mass of 21 kilodaltons.

Evidence that a human soluble beta-galactoside-binding lectin is encoded by a family of genes

Two cDNA clones were isolated by immunoscreening a human hepatoma cDNA library with an antiserum that bound specifically to a human soluble beta-galactoside-binding lectin with Mr of approximately 14,000. The deduced amino acid sequences of the inserts of these two clones show considerable homology with each other, the sequence of chicken skin beta-galactoside-binding lectin, and eight peptides derived from purified human lung lectin of Mr approximately 14,000. However, the sequence differences between the two hepatoma clones as well as among each clone and the lung peptides suggest that at least three variants of the gene encoding this lectin are expressed in human tissue.

Isolation and characterization of a galactose binding lectin with insulinomimetic activities. From the seeds of the bitter gourd Momordica charantia (Family Cucurbitaceae)

A galactose binding lectin was isolated from the seeds of the bitter gourd Momordica charantia by delipidation with petroleum ether, extraction with phosphate buffered saline, ammonium sulfate precipitation and affinity chromatography on lactogel. The lectin had a molecular weight of 124,000 and approximately 5% carbohydrate content. The molecular weights of the individual subunits were 37,000, 35,000 and 33,000. The lectin exhibited potent hemagglutinating activity. In addition, it demonstrated antilipolytic and lipogenic activities in isolated rat adipocytes although it did not possess intrinsic lipolytic activity. The antilipolytic activity was susceptible to destruction by heat, trypsin, chymotrypsin, glutathione and galactose, indicating that the integrity of the protein moiety, the disulfide linkages, and galactose, which is the sugar specifically bound by the lectin, all play an important role in interaction with the adipocyte leading to an expression of this insulin-like activity.

Galactosyl-binding lectins from the tunicate Didemnum candidum. Purification and physicochemical characterization

The plasma of the ascidian Didemnum candidum possesses lectin activity directed toward galactosyl moieties. We report the purification by affinity chromatography, the physicochemical properties, amino acid composition, and partial N-terminal amino acid sequence of two galactosyl-binding lectins D. candidum lectins I and II (DCL-I and DCL-II) from the plasma of this protochordate species. Both lectins were purified by affinity chromatography (on acid-treated Sepharose 4B and asialofetuin conjugated to Sepharose 4B) to homogeneity as judged by immunoelectrophoresis, size exclusion chromatography on high performance liquid chromatography, and polyacrylamide gel electrophoresis. Isoelectric focusing in polyacrylamide gels revealed that DCL-I focuses as a family of bands at pH 3.8-5.2, while DCL-II focuses at pH 9.2-10.2. Gas chromatography analyses of alditol acetate derivatives indicated that no carbohydrate components are associated with the lectins. Approximate subunit molecular weights estimated by polyacrylamide gel electrophoresis and size exclusion chromatography on high performance liquid chromatography in 6 M guanidine HCl under reducing conditions were 13,400-14,500 for DCL-I and 14,500-15,500 for DCL-II. Native molecular weights estimated by sedimentation equilibrium were 56,600 (DCL-I) and 57,500 (DCL-II), indicating that both species are constituted by four equal-sized subunits. Frictional ratios suggested that both lectins are globular proteins. Using rabbit antisera, the two molecules appeared serologically distinct. The extinction coefficient for DCL-I was E280 mg/ml = 2.52 ml mg-1 cm-1. Circular dichroism analyses of DCL-I suggested 29% alpha-helix and 37% beta-structure in the protein. Excitation/emission fluorescence spectra for DCL-I yielded maximum excitation and emission wavelengths at 288 and 330 nm, respectively. Amino acid compositions of DCL-I and DCL-II differed mainly in the proportions of aspartic and glutamic acids, serine, alanine, cysteine, valine, phenylalanine, and histidine. Amino acid compositions of DCL-I and DCL-II were compared to each other and to immunoglobulins and putative recognition molecules by the parameter S delta Q. DCL-I exhibited similarities in amino acid composition to lectins from the tunicate Halocynthia pyriformis, the lamprey Petromyzon marinus, and the horseshoe crab Carcinoscorpius rotundicauda, rabbit C-reactive protein, and lamprey and carp immunoglobulin mu chains. DCL-II showed amino acid composition and similarities with several fish immunoglobulin light chains, immunoglobulin-related molecules isolated from mouse and marmoset T cells, and carp and goldfish immunoglobulin heavy chains.(ABSTRACT TRUNCATED AT 400 WORDS)

Galactosyl-binding lectins from the tunicate Didemnum candidum. Carbohydrate specificity and characterization of the combining site

The plasma of the ascidian Didemnum candidum possesses lectin activity directed toward galactosyl moieties. We report the characterization of the affinity chromatography-purified galactosyl-binding lectins from the plasma of this protochordate species in terms of their hemagglutination patterns, temperature stability, saccharide specificities, divalent cation requirements, and the comparison of the properties of their combining sites to those of other characterized lectins. The major galactosyl-specific lectin, termed DCL-I, has an apparent mass of 14,500 daltons and a minor lectin (DCL-II) has an apparent subunit mass of 15,500 daltons. The two molecules differed somewhat in their hemagglutination profiles with untreated and enzyme-treated erythrocytes: a 10-fold increase in DCL-II concentration is required to obtain agglutination titers comparable to those of DCL-I. Although both DCL-I and DCL-II will agglutinate neuraminidase-treated erythrocytes from all vertebrate species tested and most Pronase-treated erythrocytes, DCL-I will agglutinate some untreated erythrocytes which are not agglutinated by DCL-II. Both lectins required divalent cations, were inactivated by temperatures above 70 degrees C, and both exhibited optimal agglutinating activity over a wide range of pH (from 5 to 11). The DCL-I molecule was characterized for its saccharide specificity by binding and inhibition assays using characterized sugars and glycoproteins. Galactose and oligosaccharides bearing nonreducing terminal galactose were the best inhibitors. The inhibition analysis indicated that the DCL-I combining site is small, interacts only with hydroxyls on carbons 2, 3, and 4 of galactose, and exhibits moderate steric hindrance for voluminous groups on carbon 6 and the alpha-anomeric linkage. The data suggest that the combining site would be smaller than the peanut lectin combining site for galactose since DCL-I does not interact with the subterminal monosaccharide hydroxyls for C4 and C6 as does peanut agglutinin. To our knowledge, this is the first isolation and detailed characterization of a lectin from a protochordate species.

Isolation and some properties of exohemagglutinin from the culture medium of Bacteroides gingivalis 381

Exohemagglutinin was found in the culture medium of Bacteroides gingivalis 381. Exohemagglutinin was purified 3,150-fold from culture fluid by ultracentrifugation followed by gel filtration on Sepharose CL-4B and by affinity chromatography on arginine-agarose. Examination of the final preparation of exohemagglutinin by biochemical analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the isolated exohemagglutinin contained three major proteins but not a detectable lipopolysaccharide. Hemagglutination inhibition experiments showed that the activity of exohemagglutinin was inhibited by L-arginine and the arginine-containing peptides, although the activity was unaffected by the sugars tested. Some protein and glycoproteins that were examined also exhibited the inhibitory activity. When the bovine submaxillary mucin was chemically modified by beta-elimination and bovine serum albumin was modified by guanidination, the inhibitory effects on hemagglutination were significantly enhanced. These results suggest that the hemagglutination of the isolated exohemagglutinin may be involved in arginine residues as components of ligand-binding sites on erythrocytes.

Monoclonal antibodies against a beta-galactoside-binding lectin of chick embryo

Monoclonal antibodies against an endogenous beta-galactoside-binding lectin (monomer molecular weight 14,000, 14K lectin) of chick embryo were prepared and characterized. The inhibitory activities against hemagglutination, antigenic determinants and binding specificities were examined. Monoclonal antibody S1A4-5 strongly inhibited the hemagglutination activity of this lectin. This antibody did not bind to any cyanogen bromide (BrCN) fragment of the lectin. Another monoclonal antibody, S1A4-3, bound to one of the BrCN fragments (residues 34-66). However, this antibody inhibited hemagglutination only weakly. The bindings to isolectins of beta-galactoside-binding lectin, namely 14K lectin (monomer molecular weight 16,000) and a third species which is assumed to be a hybrid molecule consisting of 14K and 16K lectin subunits, were examined. The antibody SIA4-5 bound to 14K lectin but not to 16K lectin. In the case of the third species, intermediate binding was observed.

Characterization of the filamentous hemagglutinin from Bordetella pertussis by gel electrophoresis

A highly purified preparation of filamentous hemagglutinin (FHA) from Bordetella pertussis was analyzed for its protein composition by gel electrophoretic methods. In this preparation of FHA the following native species could be detected by polyacrylamide gel electrophoresis (PAGE) at pH 3.2: S1 and S2 (inactive subunits or fragments); two monomers, a major form designated Ia (144K), and a minor form Ib, differing only in net charge; and three oligomeric forms, designated II (213K), III (595K) and IV (1064K). Hemagglutinating activity was associated predominantly with component Ia. PAGE of FHA after derivatization with sodium dodecyl sulfate (SDS) showed there to be three major species, designated A, C and D. According to estimated molecular weight values, A, C and D are likely to correspond to S2, Ia and II respectively. Isolated components II, III and IV yield all three SDS-species upon derivatization with SDS. Both moving boundary electrophoresis and gel electrofocusing showed hemagglutinating FHA to be a basic protein. Its apparent pI is 8.1.

Purification and properties of a hemagglutination factor from Arabian Gulf catfish (Arius thalassinus) epidermal secretion

A galactose specific lectin was isolated from an epidermal proteinaceous gel secretion of the Arabian Gulf catfish, Arius thalassinus, Ruppell. The lectin was extracted and purified to near homogeneity by exclusion chromatography, affinity chromatography and isoelectric focusing. The lectin appears to be active as a single polypeptide chain with a mol. wt near 200,000, which can form oligomers and heteropolymers. The lectin comprises about 2% of the total gel protein, lacks carbohydrates and contains no unusual types or amounts of amino acids. The lectin agglutinates a wide range of red blood cell types.

Transfer of passive immunity from mother to young in a teleost fish: haemagglutinating activity in the serum and eggs of plaice, Pleuronectes platessa L

Plaice were immunized against rabbit red blood cells (rbc) and the haemagglutinating activity in their sera and eggs was isolated by gel filtration in Sephacryl S300 SF. A "heavy" (greater than 6.69 X 10(5) Daltons) and a "light" (less than 2.32 X 10(5) Daltons) component of haemagglutinating activity were present in plaice immune serum and eggs. The "heavy" haemagglutinating component had the characteristics of immunoglobulin M (IgM) antibody. By contrast the "light" component was suppressed greatly by monosaccharides but not by 2-mercaptoethanol (2-ME) and it was not precipitable against heterologous rabbit anti-plaice Ig immune serum. Since this "light" component was also identified in the serum and eggs of non-immunized plaice the activity was attributed to non-specific lectin-like activity. The presence of an inducible, high molecular weight, haemagglutinating Ig-like protein in plaice serum and eggs suggests the possibility of transfer of passive adaptive immunity from mother to young in this fish.

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.

Reassembly of a fimbrial hemagglutinin from Pseudomonas solanacearum after purification of the subunit by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis

Distilled water homogenates of Pseudomonas solanacearum B1, a highly fimbriated strain, strongly agglutinated human group A erythrocytes. The fimbriae and hemagglutinating activity were precipitated from the crude extract with 1% acetic acid, redissolved at pH 10, and precipitated again with 20 mM CaCl2 at pH 6.9. Ca2+, Mg2+, and Zn2+ had similar ability to precipitate the fimbrial hemagglutinin, but Na+ and K+ were much less effective. The fimbrial protein in the precipitate was purified to homogeneity by preparative gel electrophoresis in sodium dodecyl sulfate. The major protein band was eluted, and sodium dodecyl sulfate was removed by chromatography on ion retardation resin (AG 11A8) in 6 M urea. After dialysis against 10 mM sodium acetate (pH 4.5) to remove the urea, the protein reassembled to yield long fibers. These fibers were identical to fimbriae in the crude extract in diameter (6 nm) and in their ability to cause hemagglutination. The purified fimbriae contained no carbohydrates and wee similar to other bacterial fimbriae in amino acid composition, with hydrophobic amino acids comprising 41.8% of the total.

A new haemagglutinin from the amoebocytes of the horseshoe crab Carcinoscorpius rotundicauda. Purification and role in cellular aggregation

The present paper describes the purification and function of a haemagglutinin from the amoebocyte lysate of the horseshoe crab Carcinoscorpius rotundicauda. The purified protein consisted of a single subunit of Mr 24 000 and agglutinated human blood-group-A+ erythrocytes. Its haemagglutinin activity was inhibited by purified lysate, coagulogen, but not by sugars. The haemagglutinin differed immunologically and in activity from the sialic-acid-binding lectin carcinoscorpin present in the haemolymph. It caused aggregation of forma-fixed amoebocytes, and on the basis of this observation its role in cell-cell adhesion is proposed. This new haemagglutinin promotes cell-cell aggregation in amoebocytes in a manner that shares some similarities with thrombospondin-mediated platelet aggregation in vertebrates [Jaffe, Leuang, Nachman, Levin & Moseher (1981) Nature (London) 295, 246-248].

Subclass distribution and molecular form of immunoglobulin A hemagglutinin antibodies in sera and nasal secretions after experimental secondary infection with influenza A virus in humans

Serum and nasal wash specimens from 13 human volunteers undergoing experimental secondary infection with influenza A/Peking/2/79 (H3N2) wild-type virus were examined for the molecular form and subclass distribution of immunoglobulin A (IgA) antibodies to the viral hemagglutinin (HA). Nasal IgA antibodies were polymeric and did not bind radiolabeled secretory component, indicating that they were secretory IgA antibodies. Both IgA1 and IgA2 antibodies were detected; however, IgA1 accounted for most of the rise in IgA anti-HA levels seen after infection. In serum virtually all of the IgA HA antibodies were of the IgA1 subclass. Furthermore, the serum antibodies were predominantly polymeric and were capable of binding radiolabeled secretory component. These results suggested that the serum IgA antibodies to HA were of mucosal origin and that influenza A virus HA preferentially stimulates an IgA1 response.

Antigenic determinants of influenza virus haemagglutinin. X. A comparison of the physical and antigenic properties of monomeric and trimeric forms

Haemagglutinin prepared from influenza virus A/Memphis/1/71 by bromelain digestion was centrifuged through continuous sucrose gradients buffered at pH 7.4 or pH 4.9. From these gradients were isolated two forms of the protein which displayed different equilibrium sedimentation properties. One species behaved as a molecule with a mol. wt. of 190 000, the other with a mol. wt. of 70 000. These results are consistent with the separation of trimeric and monomeric haemagglutinin. A comparison of their antigenic properties, using monoclonal antibodies raised against intact virus, showed that major antigenic differences occur between the two forms of haemagglutinin. None of the monoclonal antibodies reacted with haemagglutinin denatured by reduction and alkylation.

A new multimeric hemagglutinin from the coelomic fluid of the sea urchin Anthocidaris crassispina

A hemagglutinin was purified from the coelomic fluid of the sea urchin Anthocidaris crassispina by ion-exchange chromatography on DEAE-cellulose and affinity adsorption to glutaraldehyde-fixed ghosts of human erythrocytes, followed by elution with 10 mM EDTA. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, it showed a single protein band with a molecular weight of 13 000 and 26 000 in the presence and absence of 2-mercaptoethanol, respectively. The molecular weight of the native protein with a hemagglutinating activity was determined to be 300 000 by sedimentation equilibrium analysis. Its sedimentation coefficient, S0(20),w, and Stokes radius were 13.7 S and 5.5 nm, respectively. The hemagglutinating activity of this protein required calcium ions. When calcium ions were depleted, no activity was observed and its sedimentation coefficient, S0(20),w, decreased to 11.4 S while its Stokes radius increased to 6.7 nm without a change in its molecular weight. The purified hemagglutinin agglutinated human erythrocytes regardless of their ABO and MN blood types. The hemagglutination reaction was not affected appreciably by various simple sugars but was inhibited by tryptic fragments released from human erythrocyte membranes. The results of alkaline borohydride treatment of the inhibitory tryptic fragments showed that the receptor sites for this hemagglutinin were mainly composed of alkali-labile carbohydrate chains with the structure AcNeu alpha 2----3Gal beta 1----3(AcNeu alpha 2----6)GalNAc----serine (or threonine).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood group B-specific lectin of Plecoglossus altivelis (Ayu fish) eggs

A lectin that agglutinates human blood group B erythrocytes but not blood group A and O erythrocytes was isolated from eggs of Ayu sweet fish (Plecoglossus altivelis). The lectin also agglutinates Ehrlich ascites carcinoma cells but not rat ascites hepatoma AH109 or rat sarcoma 150 cells tested. The lectin agglutination was most effectively inhibited by monosaccharides with the first type of configuration, i.e., L-rhamnose, L-mannose and L-lyxose at a concentration of 0.03 mM. The lectin agglutination was moderately inhibited by monosaccharides with the second type of configuration, i.e., D-galactose, D-fucose and D-galacturonic acid at a concentration of 0.4 mM. However, the agglutination was not inhibited by various other monosaccharides and oligosaccharides that have other types of configuration. The basis for an apparent B-specific hemagglutination may be due to the steric similarity of the C2 and C4 of the galactosyl series, the B-specific determinant, and the L-rhamnosyl-Sepharose column and was characterized as a homogeneous low molecular weight protein (Mr 14000) with an abundance of hydrophobic amino acids and dicarboxylic amino acid.

[Isolation and study of the properties of the hemagglutinins produced by Streptomyces badius actinomycetes]

Hemagglutinin inducing polyagglutination of erythrocytes in the presence of the group blood sera was isolated from the supernatant of the culture fluid of Streptomyces badius 0626 by precipitation with ammonium sulfate and subsequent chromatography on Sephadex. Hemagglutinin proved to be a protein containing no lipid or carbohydrate components and possessing no bacterioagglutinating ability. Examination of the culture fluid supernatants of 150 cultures did not reveal any strains definitely exhibiting the transformation capability for human blood groups.

Characterization of Lotus tetragonolobus fucolectin components for differences in hemagglutinating and macrophage activating activities

The fucose binding proteins (FBP) extracted from Lotus tetragonolobus seeds were isolated by affinity chromatography and compared with affinity purified commercial preparations for physical, antigenic, and biological properties. All preparations contained three protein components as determined by polyacrylamide gel electrophoresis, each with a subunit molecular weight of approximately 27 Kd. FBP preparations were also found to be antigenically identical by immunodiffusion analysis and possessed similar biological activities for hemagglutination of group 0 erythrocytes and macrophage activation in the migration inhibition assay. A reversible temperature dependent hemagglutination characteristic was found; FBP agglutinated erythrocytes at 4 degrees and 22 degrees C but not at 37 degrees C, which was reversed by decreasing the incubation temperature from 37 degrees C to 22 degrees C. Temperature dependent binding of FBP for macrophages was also demonstrated. Adsorption of crude FBP by group 0 erythrocytes preferentially removed hemagglutinin without loss of macrophage activating properties. Similarly adsorption of FBP with macrophages preferentially removed macrophage activating component. Separation of the lectin components by DEAE cellulose chromatography yielded two major fractions: a potent hemagglutinin with weak macrophage activating properties and a potent macrophage activator with weak hemagglutinating activity. Separation of the crude lectin by ultrafiltration indicated that the macrophage activating component exists in a highly aggregated form which may determine its macrophage activating properties. Our results indicate that L. tetragonolobus consists of two distinct classes of components which correspond to tetrameric glycoproteins of 118-120 Kd with potent temperature dependent hemagglutinating activity and a highly aggregated dimeric component of 58 Kd with macrophage activating properties.

Isolation and characterization of chicken thymic electrolectin

We have detected the presence of a beta-D-galactoside-binding lectin (electrolectin) in extracts of the thymus of adult chickens. This lectin was purified by affinity chromatography on a lactosyl-Sepharose column to yield 1.4 mg of pure protein from 230 g of thymus. The chicken thymic electrolectin (CTE) has an Mr of 15 300 when analysed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and of 30 000 when analysed by gel filtration. The amino acid composition of CTE is similar to that of other electrolectins purified from human and rat lung. CTE cross-reacts immunologically, but is not identical, with electrolectins from electric-eel electric organ and from chick-embryo pectoral muscle. CTE agglutinates chicken thymocytes but does not appear to promote their mitosis.

Purification and characterization of the gonad lectin of Aplysia depilans

Extracts of gonads and fertilized eggs of Aplysia depilans contain a D-galacturonic and D-galactose-binding lectin. This lectin reacts strongly with rabbit and human erythrocytes independent of ABO blood groups, weakly with dog, mouse, rat, and chick erythrocytes and not at all or very weakly with sheep erythrocytes. Purification of the gonad lectin was easily achieved, with a high yield, by heating to 70 degrees C, precipitation with ammonium sulfate and affinity chromatography on Sepharose 4B. The purified lectin was found to be a glucoprotein of molecular mass around 55-60 kDa; it stimulates mitogenesis of human peripheral lymphocytes.

Separation of plasma fibronectin from associated hemagglutinating activity by elution from gelatin-agarose at pH 5.5

Human plasma fibronectin prepared by elution of the adsorbed protein from gelatin-agarose by pH 5.5 citrate buffer is very low in hemagglutinating activity toward trypsinized rabbit erythrocytes, an activity previously associated with the purified plasma protein. Hemagglutinating activity is present, however, in a subsequent fibronectin-poor 4M urea eluate which contains plasma immunoglobulins and/or other unidentified gelatin-binding proteins. This activity is partially inhibited by antibodies to human immunoglobulins, and the inhibition is reversed by excess non-specific human immunoglobulin.

Purification and partial characterization of Fusobacterium necrophorum hemagglutinin

Hemagglutinin (HAin) of Fusobacterium necrophorum was separated from the bacterial cells by trypsinization-sonication, and purified by the gel filtration on Sephadex G-100 column. The final product obtained from gel filtration gave one precipitin line in the immunodiffusion gel and produced a single band in polyacrylamide gel electrophoresis. The molecular weight of the HAin was estimated to be about 19000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis. It was heat labile and comparatively rich in alanine, glutamine and histidine. Electron microscopy observation revealed that the HAin was a filamentous rod with 0.5-1.0 nm width or frequently showed a cluster form. The hemagglutinability was inhibited by addition of albumins but not by sugars and lipopolysaccharide. Anti HAin rabbit serum inhibited hemagglutination.

Endogenous ligands of rat lung beta-galactoside-binding protein (galaptin) isolated by affinity chromatography on carboxyamidomethylated-galaptin-Sepharose

Rat lung beta-galactoside-binding protein (galaptin) is developmentally regulated during postnatal lung development. In common with other vertebrate galaptins, it is very labile when purified and dependent on the presence of exogenous thiol reagents. Reaction of rat lung galaptin with iodoacetamide resulted in a stable active carboxyamidomethylated galaptin that could be coupled to Sepharose. The resultant affinity matrix bound asialoglycoproteins, and these could be quantitatively eluted with disaccharide haptens. The carboxyamidomethylated-galaptin-Sepharose affinity matrix was used to search for endogenous ligands in 13-day-rat lung. Cytosolic fractions of developing rat lung contained no moieties that could be specifically eluted with disaccharide hapten. Only when membranous fractions were extracted with 1% Triton were glycoproteins solubilized that bound to the affinity matrix and could be specifically eluted with disaccharide hapten. The eluted glycoproteins were potent inhibitors of galaptin binding to asialo-orosomucoid. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis identified these glycoproteins as being of high Mr, with three components of Mr 160000-200000 and a smaller component of Mr 75000. This is the first evidence for specific membrane-associated glycoproteins being the ligands of rat lung galaptin.

Purification and partial characterization of filamentous haemagglutinin from Bordetella pertussis using monoclonal antibodies

Two monoclonal antibodies against filamentous haemagglutinin (F-HA) from Bordetella have been produced. In immunoblotting of a SDS-polyacrylamide gel electrophoresis (SDS-PAGE) of high ionic strength extracts of Bordetella pertussis, the two monoclonal antibodies both stained several high molecular weight bands. The two monoclonal antibodies were used for immuno-affinity column one-step purification of F-HA from high-ionic-strength extracts of Bordetella pertussis. In gradient SDS-PAGE, the eluted F-HA is present as a major double band with a molecular weight of approximately 240,000 daltons and several minor bands with molecular weights down to 90,000 daltons. The monoclonal antibodies were used in a monoclonal antibody catching enzyme linked immunosorbent assay (ELISA) for sensitive and specific detection of F-HA. This ELISA system proved valuable in optimizing the elution conditions for the monoclonal affinity columns.