Biomedical subjects

E J van Damme

Publications and source records attributed to E J van Damme.

10 recordsLinked to original sources

PubMed2001

Lectin and proteoglycan histochemistry of feline pacinian corpuscles.

We studied carbohydrate residues of glycoproteins and proteoglycans (PGs) in peritoneal Pacinian corpuscles of five adult cats. Terminal monosaccharides of glycoproteins and related polysaccharides were identified by lectin histochemistry and the PGs and glycosaminoglycans (GAGs) by specific antibodies. The most intensive lectin staining reactions indicated an abundance of glycoconjugates with terminal mannose (Man) or sialic acid residues, but no complex-type oligosaccharides were detected within the corpuscles. Terminal fucose (Fuc) and galactose (Gal) residues typical for O-linked mucin-type glycoproteins generally associated with high water binding capacity were also absent. Antibodies against unsulfated chondroitin (C-0-S), chondroitin-4-sulfate (C-4-S), and decorin showed positive reactions in the interfibrillar spaces between the lamellae, around collagen fibers, and around the lamellae of the perineural capsule, especially in the outer parts known to contain Type II collagen. Biglycan showed a preference for the innermost part of the perineural capsule (intermediate layer), known to contain Type V collagen. Collagen V and biglycan are both linked to growth processes. Hyaluronic acid (HA), chondroitin-6-sulfate (C-6-S) chains, and a chondroitin sulfate proteoglycan (CSPG) were co-localized in the terminal glia. The study of carbohydrates with high water binding capacity may contribute to our understanding of the high viscoelasticity of Pacinian corpuscles.

Animals↗

PubMed1999

Lectin binding pattern and proteoglycan distribution in human eccrine sweat glands.

The distribution pattern of glycoconjugates in human eccrine sweat glands has been studied by the binding of newly discovered lectins and by antibodies against a chondroitin sulphate proteoglycan and chondroitin sulphate glycosaminoglycans. Mannose-specific lectins labelled large intracellular granules, part of which could be extended cisternae of the endoplasmic reticulum or Golgi apparatus. In contrast, lectins specific for terminal mannose/glucose residues predominantly labelled basement membranes and the glycocalyx. Lectins recognizing terminal N-acetylgalactosamine groups left most parts of the glands unstained, but stained some dark cells intensely. These last cells were also intensively labelled by N-acetylglucosamine-specific and by fucose-specific lectins. Sialic acid residues were preferentially located in luminal borders of secretory coils. No terminal galactose residues were detected. All antibodies against chondroitin glycoconjugates stained large granules similar to those revealed by the mannose-specific lectins in the secretory cells. The basement membrane is only stained by the proteoglycan antibody and the chondroitin-6-sulphate antibody. Thus, a complex composition of glycoconjugates exists not only in matrix elements but also in the cells of eccrine glands of the human skin. A possible secretion of glycoconjugates is discussed.

Chondroitin Sulfate Proteoglycans↗

PubMed1998

Elderberry (Sambucus nigra) contains truncated Neu5Ac(alpha-2,6)Gal/GalNAc-binding type 2 ribosome-inactivating proteins.

Analysis of affinity-purified preparations of the fetuin-binding proteins from elderberry bark and fruits revealed besides the previously reported Neu5Ac(alpha-2,6)Gal/GalNAc-specific type 2 ribosome-inactivating proteins (RIP) the occurrence of single chain proteins of 22 kDa, which according to their N-terminal amino acid sequence correspond to the second part of the B chain of the respective type 2 RIP. Both proteins are very similar except that the polypeptides of the fruit lectin are 10 amino acid residues longer than these from the bark lectin. Our findings not only demonstrate the occurrence of carbohydrate-binding fragments of type 2 RIP but also provide further evidence that type 2 RIP genes give rise to complex mixtures of type 2 RIP/lectins in elderberry.

Acetylgalactosamine↗

PubMed1998

Lectin histochemistry of human leukaemic mast cells (HMC-1) transplanted into severe combined immunodeficient (scid) mice.

It is difficult to isolate and impossible to propagate human mast cells in tissue culture. As an alternative to the use of human differentiated mast cells, a human leukaemic mast cell line (HMC-1), which can be propagated in vitro, has been employed in a number of studies. Carbohydrate binding proteins, lectins, have been used to characterise the terminal sugar residues of human mast cells in situ. The aim of the present study is to characterise the lectin binding sites of HMC-1 cells transplanted into severe combined immunodeficient (scid) mice. Lectins specific for the complex carbohydrates, neuraminic acid and N-acetylglucosamine residues showed generally a strong uniform binding pattern, whereas mannose and glucose specific yielded lectins a greater heterogeneity. This glycotope expression pattern has some similarities with those of human mast cells in situ, and therefore HMC-1 cells grown in scid mice constitute a valuable model system for the study of carbohydrate expression in human mast cells.

Animals↗

PubMed1996

Lectin binding reveals divergent carbohydrate expression in human and mouse Peyer's patches.

The nature of cell-associated carbohydrates in the human intestine that may mediate transepithelial transport of bacterial and dietary lectins and their processing by the lymphoid cells of Peyer's patches is not known. Because the cell surface carbohydrate receptors for lectins may vary in different species, the glycoconjugates of human and mouse follicle-associated epithelium and gut-associated lymphoid tissue were compared. A panel of 27, mainly recently isolated, lectins were used to identify glycoconjugate expression in M-cells, enterocytes, goblet cells, lymphocytes and macrophages in mouse and human intestine. Mouse M-cells were exclusively labelled by fucose-specific lectins but in human follicle-associated epithelium no distinct M-cell staining pattern was observed. In the human Peyer's patches, Bryonia dioica lectin bound selectively to paracortical T-lymphocytes and Chelidonium majus lectin to germinal centre B-cells. Certain mannose-specific lectins (Galanthus nivalis, Hippeastrum hybrid) stained the tingible body macrophages in the germinal centre of human Peyer's patches but labelled the macrophages in the paracortical T-cell region of the mouse. The results indicate distinct differences in glycosylation between mouse and human Peyer's patches and their associated lymphoid cells. When considering cell surface glycoconjugates as target molecules for the gut immune system, care has to be taken to choose the appropriate lectin for each species.

Animals↗

PubMed1995

The role of lectins in plant defence.

Recent progress in the search for the physiological role of plant lectins supports the idea that some of these proteins are involved in the defence mechanisms of the plant. To place the evidence in favour of such a defensive role in a broad perspective, a short overview is given of the most important plant pathogens and predators. In addition, the solutions that plants have developed to resist the continuous threat of a hostile environment are briefly discussed in relation to the protective role of proteins in general. The presumed involvement of plant lectins in defence mechanisms is first inferred from an analysis of the biochemical, physiological, cellular biological and molecular biological properties of plant lectins. Subsequently, the available experimental evidence for the involvement of lectins in the plant's defence against viruses, bacteria, fungi and herbivorous invertebrates and vertebrates is discussed in some detail. Since the defensive role of plant lectins is determined largely by their ability to recognize and bind foreign glycans, a brief discussion is given of how the basically protective properties of these proteins can be exploited for histochemical applications in biological and biomedical research.

Histocytochemistry↗

PubMed1993

The alpha-mannosyl-binding lectin from leaves of the orchid twayblade (Listera ovata). Application to separation of alpha-D-mannans from alpha-D-glucans.

The carbohydrate-binding specificity of an alpha-D-mannose-specific lectin isolated from leaves of the orchid twayblade (Listera ovata) was elucidated by quantitative precipitation of mannose-containing polysaccharides and glycoproteins, hapten inhibition, and affinity chromatography on the immobilized lectin. L. ovata agglutinin (LOA) interacted with various alpha-mannans and galactomannans of yeasts, fungi and bacteria, but not with alpha-glucans, e.g., dextran and glycogen, as do mannose/glucose-binding lectins. This lectin, LOA, appears to be highly specific for alpha 1-3 mannosidic linkages. It reacted with a linear alpha 1-3-mannan (D. P. 15) and, surprisingly, even with a linear alpha 1-3-mannoheptasaccharide. The LOA/C. tropicalis mannan precipitation reaction was inhibited by alpha-linked mannooligosaccharides, in the order, alpha 1-3 > alpha 1-6 > alpha 1-2 linkages; alpha 1-3 [Man]4 and [Man]5 were the best inhibitors among various mannooligosaccharides tested, having 7-times greater potency than alpha 1-3 [Man]2, and 18-times that of methyl, alpha-mannoside. LOA/mannan interaction was also inhibited by periodate-oxidized and reduced alpha 1-3 [Man]5 which had an inhibitory potency similar to that of alpha 1-3 [Man]3, confirming that LOA also recognizes the internal alpha 1-3-mannosidic linkages of carbohydrate chains. Complete resolution of mannan and glycogen from yeast cells, by affinity chromatography on an immobilized LOA column, and retention of several high-mannose-glycoproteins suggest this lectin to be a useful tool for purification and structural investigation of alpha-mannosyl-containing polysaccharides and glycoconjugates.

Binding Sites↗

PubMed1993

Analysis of lectin binding sites in the gut of hooded Lister rats with special emphasis on recently detected lectins.

Seven recently isolated lectins were tested for their ability to bind to tissue sections of rat gut. Binding sites for N-Acetylgalactosamine specific lectins were found in mucins, in the brush border membrane and in goblet cells. Non-reducing terminal mannose residues were absent from cell surface membranes but were detected in the supranuclear region of goblet cells and enterocytes. The results of lectin binding obtained in this study were generally similar to lectin-gut interactions observed in vivo.

Acetylgalactosamine↗

PubMed1992

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

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

Amino Acid Sequence↗

PubMed1990

Relationship between survival and binding of plant lectins during small intestinal passage and their effectiveness as growth factors.

The effects on the small intestine and the growth of rats of six pure plant lectins: PHA (Phaseolus vulgaris); SBL (Glycine maxima); SNA-I and SNA-II (Sambucus nigra); GNA (Galanthus nivalis) and VFL (Vicia faba), covering most sugar specificities found in nature, were studied in vivo. Variable amounts, 25% (VFL) to 100% (PHA, GNA) of the lectins administered intragastrically, remained in immunochemically intact form in the small intestine after 1 h. All lectins, except GNA, showed binding to the brush border on first exposure, although this was slight with VFL. Thus, binding to the gut wall was not obligatory for resistance to proteolysis. Exposure of rats to lectins, except VFL, for 10 days, retarded their growth but induced hyperplastic growth of their small intestine. The two activities were directly related. PHA and SNA-II, whose intestinal binding and endocytosis was appreciable after 10 days of feeding the rats with diets containing these lectins and similar to that found on acute (1 h) exposure, were powerful growth factors for the small intestine. GNA, which did not bind at the start but was reactive after 10 days, and SNA-I, which behaved in the opposite way, induced changes in receptor expression in the gut. As they were bound to the brush border transiently, they were less effective growth factors. VFL was not bound or endocytosed, was non-toxic and did not promote gut growth.

Animals↗