Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: KEGG:D00046 (lactose)
 16,692 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Through the use of affinity chromatography, a homogeneous preparation of human beta(1 leads to 4)-D-galactosyltransferase (the A protein of lactose synthase) was obtained. The specificity of this protein for glycoconjugates was studied in the presence and absence of human alpha-lactalbumin. A kinetic analysis of the transfer of D-galactose to N-acetyl-D-glucosamine and the beta(1 leads to 4) linked N-acetylglucosamine oligomers, suggested that the active site region of the enzyme contains more than one binding site for acceptor moleucles. Furthermore, experiments with Na-acetylglucosamine-beta(1 leads to4)-N-acetylmuramic-pentapeptide isolated from Micrococcus luteus indicated that the presence of a peptide chain does not enhance enzymic activity, as compared with the corresponding free disaccharide. Similar results were obtained using ovalbumin and the ovalbumin glycopeptide (which have similar apparent Km values for A protein) as galactose acceptors. In contrast to its ability to inhibit N-acetyllactosamine production, alpha-lactalbumin did not inhibit the transfer of D-galactose to the N-acetylglucosamine oligomers or the glycopeptides. Although alpha-lactalbumin can switch the specificity of A protein from N-acetyl-D-glucosamine to D-glucose resulting in the production of lactose, no transfer of galactose was observed to beta(1 leads to 4)-linked glycose oligomers or to a collagen glycopeptide, D-glycopyranosyl-alpha(1 leads to 2)-D-galactopyranosyloxy-beta(1 leads to 5)-lysine. IT therefore appears that alpha-lactalbumin can only modify human A protein for monosaccharide acceptors.
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PMID:The binding of glycoconjugates to human-milk D-galactosyltransferase. 82 53

The marine sponge Anthosigmella varians contains proteins that agglutinate human erythrocytes irrespective of their ABO group antigens. The hemagglutination reaction depends on divalent cations and is not inhibited by L-arabinose, D-xylose, L-rhamnose, D-galactose, D-glucose, L and D-fucose, N-acetyl-D-galac-tosamine, N-acetyl-D-glucosamine, methyl-alpha-D-mannopiranoside, D-cellobiose, lactose, maltose, melibiose nor raffinose (33 mM each). A partial purification of the hemagglutinins with 31-fold increase in SA and 80% recovery of activity was obtained after gel filtration and ion-exchange gradient elution chromatography. Hemadsorption experiments carried out with the semipurified fraction using glutaraldehyde-fixed human erythrocytes suggest that proteins with molecular weight of 90 and 34 kDa participate in this reaction.
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PMID:Partial characterization of hemagglutinin activity of the marine sponge Anthosigmella varians. 130 44

Anaesthesia and surgery are known to depress granulocyte function in the early postoperative period, leading to deterioration of the immune defence against infection. Carbohydrate-lectin interactions may play an important role in the activities of phagocytic cells in that they facilitate initial host defence in the event of microbial antigenic challenge. A panel of biotinylated (neo)glycoproteins (chemically glycosilated carrier proteins) was used to detect endogenous carbohydrate-binding receptors /lectins/, on peripheral blood polymorphonuclear leukocytes of patients undergoing prolonged anaesthesia for replantation surgery. Four hours after induction of anaesthesia, a progressive decline of expression of endogenous sugar receptors on granulocytes was detected using the labelled (neo)glycoproteins lactose-BSA, N-acetyl-D-glucosamine-BSA, D-mannose-BSA, sialic-acid-BSA and D-xylose-BSA. Concomitant changes in peripheral white blood cell counts and the lack of depression in the absence of general anaesthetic agents suggested the existence of a possible relationship between reduced expression of (neo)glycoprotein receptors to impaired granulocyte function and anaesthetic-induced immunodepression.
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PMID:Changes of expression of endogenous sugar receptors by polymorphonuclear leukocytes after prolonged anaesthesia and surgery. 137 52

In the porcine prostate, glycoconjugates elaborated and released by the glandular cells have been studied by means of a series of histochemical methods of light microscopy. The employed methods included several routine procedures in combination with digestion by carbohydrate-degrading enzymes and peroxidase-labelled lectin diaminobenzidine procedures. In the glandular tissues, the particular glycoconjugates were shown to be secretory glycoproteins which contained vicinal diol, sulphate, and carboxyl groups and were provided with different saccharide residues such as alpha-D-mannose, alpha-D-glucose, lactose, N-acetyl-D-galactosamine, beta-D-galactose, alpha-L-fucose, N-acetyl-D-glucosamine, and N-acetyl-neuraminic acid. These glycoconjugates were, likewise, found to exhibit positive reaction for proteins. The present histochemical results have been discussed with special reference to the histophysiological functions performed by the prostate gland in the pig.
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PMID:Glycoconjugate histochemistry of the prostate gland in the pig. 169 77

Chemotherapy does not only affect the viability of the tumor cell. It may also cause alterations in normal organs. Thus, tumor-free areas within human lung parenchyma of 63 surgical specimens of intrapulmonary metastases were analyzed to assess the extent of morphologic changes in response to previous cytostatic therapy. The material included 34 cases of sarcoma, 20 cases of germ cell tumors, 6 cases of hypernephroid carcinoma, two cases of mammary carcinoma and one case of metastatic melanoma. All patients had received cytostatic therapy in generally applied regimens for more than two years. Morphologic analysis was carried out by routine procedures. In addition to conventional staining procedures including HE, PAS, and Sirius stain, further tools were employed to extend the array of determined characteristics. To evaluate any changes in the tissue in order to specifically recognized carbohydrate structures, labeled neoglycoproteins or proteoglycans with specificity for endogenous receptors that bind to mannose, maltose, L-fucose, lactose, N-acetyl-D-glucosamine, and heparin were used. A monoclonal antibody binding the HLA-DR receptor was also included in the study. As a control, sections of 20 cases with intrapulmonary metastases without exposure to previous cytostatic therapy were included. To address the further question whether cytostatic therapy may induces changes in tumor-free lung that show similarities to the organ in question, sections from 18 cases with tuberculosis and from 37 cases suffering from sarcoidosis were similarly examined. Focal interstitial fibrosis was seen in 28/63 (44%) of the patients receiving chemotherapy. In contrast, only 2/20 (10%) patients of the untreated group exhibited this alteration. An active fibrosis with proliferating smooth muscle cells was found in two cases, dysplastic pneumocytes in 10 cases (16%) in the group with cytostatic therapy, but in no cases in the untreated group. Expression of the HLA-DR receptor in the pneumocytes was observed in 27/63 cases (43%) of the cytostatic cohort, in 21/37 (57%) patients of the sarcoidosis cohort, in 15/18 (83%) patients of the tuberculosis cohort, and in 1/20 (5%) of the untreated patients. In contrast to sections from treated patients, binding of neoglycoproteins was low in the untreated cohort. Interestingly, similarities between the tuberculosis cohort and the cytostatic cohort were seen for receptors that are specific for fucose and lactose, respectively. The results suggest that long-lasting cytostatic therapy induces focal fibrosis in 40%-50% of the patients, mainly via unspecific interstitial inflammatory infiltrates. A hypersensitivity reaction or direct toxicity may less frequently lead to pathologic alterations.
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PMID:Alterations in human lung parenchyma after cytostatic therapy. 200 Dec 78

Guanidine extracts of crude Bacillus anthracis cell wall were used to vaccinate BALB/c mice and to develop monoclonal antibody (MAb) to vegetative cell surface antigens. Two hybridomas selected during this study produced immunoglobulin M immunoglobulins, which appear to be directed to an epitope associated with the galactose-N-acetyl-D-glucosamine polysaccharide. Both demonstrated specificity in their binding to purified B. anthracis cell wall, o-stearoyl-polysaccharide conjugates, and intact, nonencapsulated vegetative cells. The interaction of the MAbs with purified polysaccharide was inhibited by 0.5 M galactose and lactose but not by N-acetylglucosamine, glutamate, glycine, or glycerol. Inhibition by glucose or sucrose was approximately 75% of that seen with galactose. Electron microscopy showed that both MAbs interacted with the cell wall of vegetative cells as well as with the cortex of spores. Neither MAb reacted with encapsulated vegetative cells, such as those from infected guinea pigs, nor did they react with intact spores. After conjugation to fluorescein isothiocyanate, the MAbs stained intensely all B. anthracis strains tested, whereas with two exceptions, none of the strains of 20 other Bacillus spp. was stained. The exceptions, strains of Bacillus cereus, could be differentiated from B. anthracis by being beta-hemolytic on blood agar.
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PMID:Identification of Bacillus anthracis by using monoclonal antibody to cell wall galactose-N-acetylglucosamine polysaccharide. 210 1

Two male patients aged 12 and 31 years suffered from Crohn's disease for more than six years and were treated with Cortison for more than four years. Surgical excision of parts of the terminal ileum was performed in both patients. They suffered from pulmonary symptoms as dyspnoea, shortness of breath and ventilation disturbances two years after operation. Wedge biopsies of the lungs revealed the following histomorphological findings: 1. Granulomatous interstitial lymphocyte infiltrates 2. Acute alveolitis with severe dysplasia of pneumocytes 3. Moderate interstitial fibrosis. Immunohistology performed in one case showed predominantly lambda chains expressed by lymphocytes associated with IgA and IgM. IgG was missing, furthermore kappa chains could not be detected. Macrophages contained endogenous lectins (sugar receptors) for fucose, maltose, and N-acetyl-D-glucosamine (glcNAc). No receptors specific for mannose, lactose, and heparin could be found. Pneumocytes did not bind the neoglycoproteins but were found to express HLA-DR receptors detectable by the monoclonal antibody LN 3 in dysplastic pneumocytes only. The histomorphological and immunohistochemical findings suggest that the analyzed alterations of lung tissue are related to the underlying disease of enteritis regionalis.
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PMID:Are there characteristic alterations in lung tissue associated with Crohn's disease? 224 78

Fusobacterium nucleatum expresses lectinlike adherence factors which mediate binding to a variety of human tissue cells. Adherence is selectively inhibited by galactose, lactose, and N-acetyl-D-galactosamine. In this study, adherence of F. nucleatum to human peripheral blood polymorphonuclear neutrophils (PMNs) was investigated. The results indicated that the fusobacteria adhered to live and metabolically inactivated or fixed PMNs. Adherence of F. nucleatum resulted in activation of PMNs as determined by PMN aggregation, membrane depolarization, increased intracellular free Ca2+, superoxide anion production, and lysozyme release. Transmission electron micrographs showed that F. nucleatum was phagocytized by the PMNs. Microbicidal assays indicated that greater than 98% of F. nucleatum organisms were killed by PMNs within 60 min. Adherence to and activation of PMNs by F. nucleatum were inhibited by N-acetyl-D-galactosamine or lactose greater than galactose, whereas equal concentrations of glucose, N-acetyl-D-glucosamine, mannose, and fucose had little or no effect on F. nucleatum-PMN interactions. Pretreatment of the fusobacteria with heat (80 degrees C, 20 min) or proteases inhibited adherence to and activation of PMNs, but superoxide production was also stimulated by heated bacteria. The results indicate that interaction of F. nucleatum with PMNs is lectinlike and is probably mediated by fusobacterial proteins which bind to other human tissue cells. Adherence of F. nucleatum to PMNs in the absence of serum opsonins, such as antibodies and complement, may play an important role in PMN recognition and killing of F. nucleatum in the gingival sulcus and in the subsequent release of PMN factors associated with tissue destruction.
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PMID:Lectinlike interactions of Fusobacterium nucleatum with human neutrophils. 255 9

Partially and highly purified lectins from Viscum album L. (mistletoe) cause a dose-dependent decrease of viability of human leukemia cell cultures, MOLT-4, after 72 h treatment. The LC50 of the partially purified lectin was 27.8 ng/ml, of the highly purified lectin 1.3 ng/ml. Compared to the highly purified lectin a 140-fold higher protein concentration of an aqueous mistletoe drug was required to obtain similar cytotoxic effects on MOLT-4 cells. Cytotoxicity of the highly purified lectin was preferentially inhibited by D-galactose and lactose, cytotoxicity of the mistletoe drug and the partially purified lectin were preferentially inhibited by lactose and N-acetyl-D-galactosamine (GalNAc). Two lectin fractions with almost the same cytotoxic activity on MOLT-4 cells but with different carbohydrate affinities were isolated by affinity chromatography from the mistletoe drug: mistletoe lectin I with an affinity to D-galactose and GalNAc and mistletoe lectin II with an affinity to GalNAc. The lectin fractions and the mistletoe drug inhibited protein synthesis of MOLT-4 cells stronger than DNA synthesis. Furthermore a subpopulation of MOLT-4, resistant to cytotoxic doses of both the mistletoe drug and the mistletoe lectins, was shown to exhibit a reduced amount of GalNAc and N-acetyl-D-glucosamine in their cellular glycoproteins which are probably responsible for the binding of the cytotoxic lectins. These results indicate that lectins are the main toxins in the mistletoe drug.
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PMID:Influence of carbohydrates on the cytotoxicity of an aqueous mistletoe drug and of purified mistletoe lectins tested on human T-leukemia cells. 277 29

The coaggregation of Fusobacterium nucleatum PK1594 and Porphyromonas (Bacteroides) gingivalis PK1924 was inhibited equally well by lactose, N-acetyl-D-galactosamine, and D-galactose, which caused 50% inhibition of coaggregation at 2 mM sugar concentration. Other sugars such as D-galactosamine, D-fucose (6-deoxy-D-galactose), and alpha-methyl- and beta-methyl-D-galactosides also inhibited coaggregation. Sugar specificity was apparent, since neither L-fucose, L-rhamnose, N-acetyl-D-glucosamine, nor N-acetylneuraminic acid was an inhibitor. Protease treatment of the fusobacterium completely abolished coaggregation, whereas it had no effect on the coaggregating activity of the porphyromonad. Although numerous lactose-inhibitable coaggregating pairs are known to occur among gram-positive bacteria, this report and the accompanying survey (P. E. Kolenbrander, R. N. Andersen, and L. V. H. Moore, Infect. Immun. 57:3194-3203, 1989) are the first studies demonstrating the extensive nature of this type of interaction between gram-negative human oral bacteria. The significance of galactoside-inhibitable coaggregations between these two potential periodontal pathogens is discussed.
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PMID:Inhibition of coaggregation between Fusobacterium nucleatum and Porphyromonas (Bacteroides) gingivalis by lactose and related sugars. 277 79


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