Optimizing Fluorescein Isothiocyanate Dextran Measurement As a Biomarker in a 24-h Feed Restriction Model to Induce Gut Permeability in Broiler Chickens

Directory of Open Access Journals (Sweden)

Guillermo Tellez

2017-04-01

Full Text Available Fluorescein isothiocyanate dextran (FITC-d is a 3–5 kDa marker used to measure tight junction permeability. We have previously shown that intestinal barrier function can be adversely affected by stress, poorly digested diets, or feed restriction (FR, resulting in increased intestinal inflammation-associated permeability. However, further optimization adjustments of the current FITC-d methodology are possible to enhance precision and efficacy of results in future. The objective of the present study was to optimize our current model to obtain a larger difference between control and treated groups, by optimizing the FITC-d measurement as a biomarker in a 24-h FR model to induce gut permeability in broiler chickens. One in vitro and four in vivo independent experiments were conducted. The results of the present study suggest that by increasing the dose of FITC-d (8.32 versus 4.16 mg/kg; shortening the collection time of blood samples (1 versus 2.5 h; using a pool of non-FITC-d serum as a blank, compared to previously used PBS; adding a standard curve to set a limit of detection and modifying the software’s optimal sensitivity value, it was possible to obtain more consistent and reliable results.

Precocious development of lectin (Ulex europaeus agglutinin I) receptors in dome epithelium of gut-associated lymphoid tissues.

Science.gov (United States)

Roy, M J

1987-06-01

Dome epithelium (DE), the tissue covering lymphoid domes of gut-associated lymphoid tissues, was examined in both adult and neonatal rabbit appendix or sacculus rotundus to determine if dome epithelial cells matured earlier than epithelial cells covering adjacent villi. The localization of well-differentiated epithelial cells in rabbit gut-associated lymphoid tissues (GALT) was accomplished histochemically by use of molecular probes: fluorescein isothiocyanate or horseradish peroxidase conjugates of Ulex europaeus agglutinin I (UEA), a lectin specific for terminal L-fucose molecules on certain glycoconjugates. The villus epithelial cells of newborn and 2-, 5-, or 10-day-old rabbits did not bind UEA, but between the twelfth and fifteenth days of postnatal life, UEA receptors were expressed by well-differentiated villus epithelial cells. In contrast to villus epithelium, DE in appendix and sacculus rotundus of neonatal rabbits expressed UEA receptors two days after birth, a feature that distinguished the DE of neonatal GALT for the next two weeks. In adult rabbits, UEA receptors were associated with dome epithelial cells extending from the mouths of glandular crypts to the upper domes; in contrast to the domes, UEA receptors were only present on well-differentiated epithelial cells at the villus tips. Results suggested that in neonatal rabbits most dome epithelial cells developed UEA receptors shortly after birth, reflecting precocious development of DE as compared to villus epithelium. In adult rabbit dome epithelium UEA receptors appeared on dome epithelial cells as they left the glandular crypts, representing accelerated epithelial maturation.

Lectin binders

International Nuclear Information System (INIS)

Rudiger, H.; Gebauer, G.; Gansera, R.; Schurz, H.; Schimpl, A.

1982-01-01

Lectins are widely distributed in the plant kingdom, many of them being well characterized in their chemical structure and the effects they have on alien biological systems such as erythrocytes or lymphocytes. The biological function of plant lectins remains speculative. We therefore inspected plant extracts from components which might bind specifically to the lectin from the respective plant. Single proteins (lectin binders) could be isolated from each plant extract. The interaction of these proteins with lectins was demonstrated and qualified by several methods. Similar to the lectins, the lectin binders are localized in the cytoplasm in contrast to them, however, they persist during germination and plant growth. Their precise role in the plant is not known, but they are likely to be associated with lectins not only in vitro but also in vivo. They also interact with alien cells, and are able to stimulate mitosis in murine lymphocytes. Some lectin binders act specifically on B lymphocytes, leaving T cells uninfluenced

Histopathological confirmation of similar intramucosal distribution of fluorescein in both intravenous administration and local mucosal application for probe-based confocal laser endomicroscopy of the normal stomach.

Science.gov (United States)

Nonaka, Kouichi; Ohata, Ken; Ban, Shinichi; Ichihara, Shin; Takasugi, Rumi; Minato, Yohei; Tashima, Tomoaki; Matsuyama, Yasushi; Takita, Maiko; Matsuhashi, Nobuyuki; Neumann, Helmut

2015-12-16

Probe-based confocal laser endomicroscopy (pCLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. pCLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared

Fluorescein isothiocyanate labeled, magnetic nanoparticles conjugated D-penicillamine-anti-metadherin and in vitro evaluation on breast cancer cells

International Nuclear Information System (INIS)

Akca, Ozlet; Unak, Perihan; Medine, E. Ylker; Sakarya, Serhan; Ozdemir, Caglar; Timur, Suna

2011-01-01

Silane modified magnetic nanoparticles were prepared after capped with silica generated from the hydrolyzation of tetraethyl orthosilicate (TEOS). Amino silane (SG-Si900) was added to this solution for surface modification of silica coated magnetic particles. Finally, D-penicillamine (D-PA)-antimetadherin (anti-MTDH) was covalently linked to the amine group using glutaraldehyde as cross-linker. Magnetic nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and atomic force microscopy (AFM). AFM results showed that particles are nearly monodisperse, and the average size of particles was 40 to 50 nm. An amino acid derivative D-PA was conjugated anti-MTDH, which results the increase of uptaking potential of a conjugated agent, labelled fluorescein isothiocyanate (FITC) and then conjugated to the magnetic nanoparticles. In vitro evaluation of the conjugated D-PA-anti-MTDH-FITC to magnetic nanoparticle was studied on MCF-7 breast cancer cell lines. Fluorescence microscopy images of cells after incubation of the sample were obtained to monitor the interaction of the sample with the cancerous cells. Incorporation on cells of FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH was found higher than FITC labeled D-PA-anti-MTDH. The results show that magnetic properties and application of magnetic field increased incorporation rates. The obtained D-PA-anti-MTDH-magnetic nanoparticles-FITC complex has been used for in vitro imaging of breast cancer cells. FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH may be useful as a new class of scintigraphic agents. Results of this study are sufficiently encouraging to bring about further evaluation of this and related compounds for ultraviolet magnetic resonance (UV-MR) dual imaging. (author)

Isothiocyanates: a review

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Chandra Kala*

2018-04-01

Full Text Available Isothiocyanates (ITCs are naturally occurring molecules belonging to highly reactive organosulphur synthons, with the general structure R–N=C=S. The precursor molecule glucosinolate anions are hydrolyzed enzymatically (under the effect of myrosinase enzymes or unenzymatically to produce nitriles or isothiocyanates depending upon conditions such as pH and temperature. Brassicaceae  Family is known to contain abundant ITCs. A significant number of isothiocyanates has been isolated from different plant sources and some of them have been synthesized. Several isothiocyanates have demonstrated significant pharmacological activities including anti-cancer, anti-inflammatory, anti-microbial activities, etc. Pharmacokinetic profiles of these sulphur containing compounds are well established. However, safety profiles of ITCs need consideration and a well-designed study with appropriate control, for their production as lead compounds. This review summarises the chemistry, sources, pharmacokinetics, pharmacological activity and toxicity profiles of the isothiocyanates.

Double-modification of lectin using two distinct chemistries for fluorescent ratiometric sensing and imaging saccharides in test tube or in cell.

Science.gov (United States)

Nakata, Eiji; Koshi, Yoichiro; Koga, Erina; Katayama, Yoshiki; Hamachi, Itaru

2005-09-28

The site-selective incorporation of two different fluorophores into a naturally occurring protein (lectin, a sugar-binding protein) has been successfully carried out using two distinct orthogonal chemical methods. By post-photoaffinity labeling modification, Con A, a glucose- and mannose-selective lectin, was modified with fluorescein in the proximity of the sugar binding site (Tyr100 site), and the controlled acylation reaction provided the site-selective attachment of coumarin at Lys114. In this doubly modified Con A, the fluorescein emission changed upon the binding to the corresponding sugars, such as the glucose or mannose derivatives, whereas the coumarin emission was constant. Thus, the doubly modified Con A fluorescently sensed the glucose- and mannose-rich saccharides in a ratiometric manner while retaining the natural binding selectivity and affinity, regardless of the double modification. On the benefit of the ratiometric fluorescent analysis using two distinct probes, the sugar trimming process of a glycoprotein can be precisely monitored by the engineered Con A. Furthermore, the doubly modified Con A can be used not only for the convenient fluorescent imaging of saccharides localized on a cell surface, such as the MCF-7, a breast cancer cell having rich high-mannose branch, but also for the ratiometric fluorescent sensing of the glucose concentration inside HepG2 cells. These results demonstrated that the semisynthetic lectin modified doubly by two distinct chemistries is superior to the singly modified one in function, and thus, it may be potentially useful in cell, as well as in test tube.

Lectin receptor kinase LecRK-b2 localizes to plasma membrane and ...

African Journals Online (AJOL)

-b2, has been characterized. Confocal microscopy images showed that the LecRK-b2-GFP fusion protein is localized to plasma membrane. The results of yeast 2 hybrid showed that lectin domain of LecRK-b2 had selfinteraction, while the ...

Isothiocyanates: a review

OpenAIRE

Chandra Kala*; Syed Salman Ali; Nabeel Ahmad; Sadaf Jamal Gilani; Najam Ali Khan

2018-01-01

Isothiocyanates (ITCs) are naturally occurring molecules belonging to highly reactive organosulphur synthons, with the general structure R–N=C=S. The precursor molecule glucosinolate anions are hydrolyzed enzymatically (under the effect of myrosinase enzymes) or unenzymatically to produce nitriles or isothiocyanates depending upon conditions such as pH and temperature. Brassicaceae  Family is known to contain abundant ITCs. A significant number of isothiocyanates has been isolated from differ...

Local pH at the surface of hen egg white lysozyme

Science.gov (United States)

Otosu, Takuhiro; Kobayashi, Kaito; Yamaguchi, Shoichi

2018-02-01

The microenvironment at the surface of hen-egg-white lysozyme (HEWL) was examined by analyzing the change in pKa of fluorescein isothiocyanate (FITC) upon binding to the N-terminus of HEWL. The result showed that the local pH at the HEWL surface is higher than the bulk pH. Furthermore, the data showed that the difference between the local and bulk pH becomes larger with decreasing pH, suggesting HEWL repels more protons at lower pH. Because the local pH affects the protonation states of functional amino-acids at the protein surface, the results provide the fundamental insight into the microenvironment at the protein surface.

Exploitation of phosphorescent labelling reagent of fullerol-fluorescein isothiocyanate and new method for the determination of trace alkaline phosphatase as well as forecast of human diseases

International Nuclear Information System (INIS)

Liu Jiaming; Huang Xiaomei; Liu Zhenbo; Lin Shaoqin; Li Feiming; Gao Fei; Li Zhiming; Zeng Liqing; Li Lianying; Ouyang Ying

2009-01-01

A new phosphorescent labelling reagent consisting of fullerol, fluorescein isothiocyanate and N,N-dimethylaniline (F-ol-(FITC) n -DMA) was developed. The mode of action is based on the reactivity of the active -OH group in F-ol with the -COOH group of FITC to form an F-ol-(FITC) n -DMA complex containing several FITC molecules. F-ol-(FITC) n -DMA increased the number of luminescent molecules in the biological target of WGA-AP-WGA-F-ol-(FITC) n -DMA (WGA and AP are wheat germ agglutinin and alkaline phosphatase, respectively) which improved the sensitivity using solid substrate room temperature phosphorimetry (SSRTP) detection. The proposed method provided high sensitivity and strong specificity for WGA-AP. The limit of detection (LD) was 0.15 ag AP spot -1 for F-ol and 0.097 ag AP spot -1 for FITC in F-ol-(FITC) n -DMA, which was lower than the method using single luminescent molecules of F-ol-DMA and FITC-DMA to label WGA (0.20 ag AP spot -1 for F-ol-DMA and 0.22 ag AP spot -1 for FITC-DMA). Results for the determination of AP in human serum were in good agreement with those obtained by enzyme-linked immunosorbent assay. The mechanism of F-ol-(FITC) n -DMA labelling of WGA was discussed.

Molecular imaging of a cell-penetrating peptide labeled fluorescein-5-isothiocyanate and MR contrast agents: gadopentetate dimeglumine

International Nuclear Information System (INIS)

Liu Min; Guo Youmin; Duan Xiaoyi; Guo Xiaojuan; Yang Junle; Xu Min

2006-01-01

Objective: To study the value of a new intracellular contrast agent--cell penetrating peptide labeled Fluorescein-5-isothiocyanate (FITC) and MRI contrast agent, Gadopentetate dimeglumine in molecular imaging. Methods: A new cell penetration peptides (CPPs)sequence LAGRRRRRRRRRK were synthesized in solid phase on the base of arginine (9) and were labelled with FITC (CPP 13 -FITC) and Gd - DTPA (CPP 13 -DTPA-Gd). Hepatic carcinoma cell line-HEPG 2 and mouse bone marrow stem cell was respectively stained by CPP 13 -FITC for different time intervals for observing the uptake and intracellular distribution. HEPG 2 in three l00 mm 2 culture plates was respectively incubated with CPP 13 -DTPA-Gd, Gd- DTPA and Dulbecco minimum essential medium for 30 min and imaged by 1.5 T MRI for studying the intracellular uptake and T 1 WI signal characteristics. Results: The peptide was synthesized by the manual solid-phase method successfully. The calculated molecular weight was 1792.78 and the chemical purity was over 95%. By inverted fluorescence microscope, HEPG 2 and mouse stem cell could transport CPP-FITC in cytoplasm and nuclear in 10 min. By MR imaging, CPP-DTPA-Gd could be uptake by HEPG 2 in 30 min and had a short T 1 short T 2 signal, furthermore. T 1 WI signal intensity ratio between in-tube (Ii) and out-tube (Io) in three groups of three scan slices were shown below: Iil/Io of group 1 (Group 1 was the cell incubated by CPP 13 -DTPA-Gd ) respectively was 2.84, 2.60, 2. 48; Iil/Io of group 2 (Group 2 was the cell incubated by DTPA-Gd) respectively is 1.15, 1.11, 1.12; Iil/Io of group 3 (Group 3 was the controled cell ) respectively was 1.15, 1.11, 1.11. By ANVOA analysis, the signal intensity among group 1, group 2 and group 3 had significant difference(F (1,2) = 201.88 P (1,3) =206.37 P (2,3) =0.529 P=0.507). Conclusion: The new constructed cell penetration peptide on the base of the polyargnine can translocate cell by carting FITC and MRI contrast agent-DTPA-Gd and the

Lectins from Mycelia of Basidiomycetes

Directory of Open Access Journals (Sweden)

Valentina E. Nikitina

2017-06-01

Full Text Available Lectins are proteins of a nonimmunoglobulin nature that are capable of specific recognition of and reversible binding to the carbohydrate moieties of complex carbohydrates, without altering the covalent structure of any of the recognized glycosyl ligands. They have a broad range of biological activities important for the functioning of the cell and the whole organism and, owing to the high specificity of reversible binding to carbohydrates, are valuable tools used widely in biology and medicine. Lectins can be produced by many living organisms, including basidiomycetes. Whereas lectins from the fruit bodies of basidiomycetes have been studied sufficiently well, mycelial lectins remain relatively unexplored. Here, we review and comparatively analyze what is currently known about lectins isolated from the vegetative mycelium of macrobasidiomycetes, including their localization, properties, and carbohydrate specificities. Particular attention is given to the physiological role of mycelial lectins in fungal growth and development.

[Endoscopic endonasal detection of cerebrospinal fluid leakage with topical fluorescein].

Science.gov (United States)

Sato, Taku; Kishida, Yugo; Watanabe, Tadashi; Tani, Akiko; Tada, Yasuhiro; Tamura, Takamitsu; Ichikawa, Masahiro; Sakuma, Jun; Omori, Koichi; Saito, Kiyoshi

2013-08-01

We evaluated the effectiveness of intraoperative topical application of fluorescein to detect the leakage point of cerebrospinal fluid(CSF)rhinorrhea. Three patients with CSF rhinorrhea were treated with an endoscopic endonasal technique. Ten percent fluorescein was topically used for intraoperative localization of the leak site. A change of the fluorescein color from brown to green due to dilation of CSF were recognized as evidence of CSF rhinorrhea. We repeated the procedure to detect any small defects. All CSF rhinorrheas were successfully repaired by this endoscopic endonasal approach. Topical application of fluorescein is simple and sensitive for identifying intraoperative CSF rhinorrhea.

Compound list: naphthyl isothiocyanate [Open TG-GATEs

Lifescience Database Archive (English)

Full Text Available naphthyl isothiocyanate ANIT 00009 ftp://ftp.biosciencedbc.jp/archive/open-tggates/...LATEST/Human/in_vitro/naphthyl_isothiocyanate.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/op...en-tggates/LATEST/Rat/in_vitro/naphthyl_isothiocyanate.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/arc...hive/open-tggates/LATEST/Rat/in_vivo/Liver/Single/naphthyl_isothiocyanate.Rat.in_...vivo.Liver.Single.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/naphthyl_isothiocyanate.Rat.in_vivo.Liver.Repeat.zip ...

Lectin binders. A new group of plant proteins

Energy Technology Data Exchange (ETDEWEB)

Rudiger, H; Gebauer, G; Gansera, R; Schurz, H; Schimpl, A [Wuerzburg Univ. (Germany, F.R.)

1982-09-01

Lectins are widely distributed in the plant kingdom, many of them being well characterized in their chemical structure and the effects they have on alien biological systems such as erythrocytes or lymphocytes. The biological function of plant lectins remains speculative. We therefore inspected plant extracts from components which might bind specifically to the lectin from the respective plant. Single proteins (lectin binders) could be isolated from each plant extract. The interaction of these proteins with lectins was demonstrated and qualified by several methods. Similar to the lectins, the lectin binders are localized in the cytoplasm in contrast to them, however, they persist during germination and plant growth. Their precise role in the plant is not known, but they are likely to be associated with lectins not only in vitro but also in vivo. They also interact with alien cells, and are able to stimulate mitosis in murine lymphocytes. Some lectin binders act specifically on B lymphocytes, leaving T cells uninfluenced.

Cyborg lectins: novel leguminous lectins with unique specificities.

Science.gov (United States)

Yamamoto, K; Maruyama, I N; Osawa, T

2000-01-01

Bauhinia purpurea lectin (BPA) is one of the beta-galactose-binding leguminous lectins. Leguminous lectins contain a long metal-binding loop, part of which determines their carbohydrate-binding specificities. Random mutations were introduced into a portion of the cDNA coding BPA that corresponds to the carbohydrate-binding loop of the lectin. An library of the mutant lectin expressed on the surface of lambda foo phages was screened by the panning method. Several phage clones with an affinity for mannose or N-acetylglucosamine were isolated. These results indicate the possibility of making artificial lectins (so-called "cyborg lectins") with distinct and desired carbohydrate-binding specificities.

Detection of nearest neighbors to specific fluorescently tagged ligands in rod outer segment and lymphocyte plasma membranes by photosensitization of 5-iodonaphthyl 1-azide

International Nuclear Information System (INIS)

Raviv, Y.; Bercovici, T.; Gitler, C.; Salomon, Y.

1989-01-01

Lima bean agglutinin-fluorescein 5-isothiocyanate conjugate (FluNCS-lima bean lectin) interacts with specific receptor molecules on membranes both from the rod outer segment (ROS) of the frog retina and from S49 mouse lymphoma cells. When [125I]-5-iodonaphthyl 1-azide (125I-INA), which freely and randomly partitions into the lipid bilayer, is added to membranes and the suspension is irradiated at 480 nm, the FluNCS-conjugated lectin photosensitizes the [125I]INA but only at discrete sites. This results in the selective labeling of specific proteins: an 88-kDa protein on ROS membranes and a 56-kDa protein on S49 plasma membranes. Labeling is dependent upon the interaction of the FluNCS-lectin with glycosylated receptor sites, since N-acetylgalactosamine, but not methyl alpha-mannoside, blocked labeling of the 56-kDa protein on S49 membranes. In contrast, a random labeling pattern of membrane proteins was observed upon irradiation at 480 nm using other fluorescein conjugates, such as FluNCS-bovine serum albumin (FluNCS-BSA) or FluNCS-soybean trypsin inhibitor (FluNCS-STI), which interact with cell membranes in a nonselective manner, or with N-(fluorescein-5-thiocarbamoyl)-n-undecyclamine (FluNCS-NHC11), which is freely miscible in the membrane lipid. Random labeling was also obtained by direct photoexcitation of [125I]INA at 314 nm, with no distinct labeling of the 88- and 56-kDa proteins in the respective membranes. These results suggest that protein ligands can be used to guide sensitizers to discrete receptor sites and lead to their selective labeling by photosensitized activation of [125I]INA

Fluorescein-related extensive jaundice.

Science.gov (United States)

Kalkan, Asim; Turedi, Suleyman; Aydin, Ibrahim

2015-03-01

Fluorescein is a chemical dye frequently used in eye diseases to assess blood flow in the retina, choroid tissue, and iris. Although it has many known adverse effects, it has not previously been reported to lead to jaundice. The purpose of this case report was to emphasize that for patients presenting at the emergency department with jaundice symptoms, it should not be forgotten by emergency physicians that jaundice can develop after fluorescein angiography. Case: A 65-year-old woman presented at the emergency department with extensive jaundice that had developed on her entire body a few hours after fluorescein angiography applied because of vision impairment. The test results for all the diseases considered to cause jaundice were normal,and fluorescein-related jaundice was diagnosed. Conclusion: A detailed anamnesis should be taken when jaundice is seen in patients who have undergone fluorescein angiography, and it should not be forgotten that fluorescein dye is a rare cause of jaundice.

Transient receptor potential ankyrin 1 activation enhances hapten sensitization in a T-helper type 2-driven fluorescein isothiocyanate-induced contact hypersensitivity mouse model

International Nuclear Information System (INIS)

Shiba, Takahiro; Tamai, Takuma; Sahara, Yurina; Kurohane, Kohta; Watanabe, Tatsuo; Imai, Yasuyuki

2012-01-01

Some chemicals contribute to the development of allergies by increasing the immunogenicity of other allergens. We have demonstrated that several phthalate esters, including dibutyl phthalate (DBP), enhance skin sensitization to fluorescein isothiocyanate (FITC) in a mouse contact hypersensitivity model, in which the T-helper type 2 (Th2) response is essential. On the other hand, some phthalate esters were found to activate transient receptor potential ankyrin 1 (TRPA1) cation channels on sensory neurons. We then found a positive correlation between the enhancing effects of several types of phthalate esters on skin sensitization to FITC and their ability to activate TRPA1. Here we examined the involvement of TRPA1 in sensitization to FITC by using TRPA1 agonists other than phthalate esters. During skin sensitization to FITC, the TRPA1 agonists (menthol, carvacrol, cinnamaldehyde and DBP) augmented the ear-swelling response as well as trafficking of FITC-presenting dendritic cells to draining lymph nodes. We confirmed that these TRPA1 agonists induced calcium influx into TRPA1-expressing Chinese hamster ovary (CHO) cells. We also found that TRPA1 antagonist HC-030031 inhibited DBP-induced calcium influx into TRPA1-expressing CHO cells. After pretreatment with this antagonist upon skin sensitization to FITC, the enhancing effect of DBP on sensitization was suppressed. These results suggest that TRPA1 activation will become a useful marker to find chemicals that facilitate sensitization in combination with other immunogenic haptens. -- Highlights: ► Role of TRPA1 activation was revealed in a mouse model of skin sensitization to FITC. ► TRPA1 agonists enhanced skin sensitization as well as dendritic cell trafficking. ► Dibutyl phthalate (DBP) has been shown to enhance skin sensitization to FITC. ► TRPA1 activation by DBP was inhibited by a selective antagonist, HC-030031. ► HC-030031 inhibited the enhancing effect of DBP on skin sensitization to FITC.

Transient receptor potential ankyrin 1 activation enhances hapten sensitization in a T-helper type 2-driven fluorescein isothiocyanate-induced contact hypersensitivity mouse model

Energy Technology Data Exchange (ETDEWEB)

Shiba, Takahiro; Tamai, Takuma; Sahara, Yurina; Kurohane, Kohta [Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, 52‐1 Yada, Suruga-ku, Shizuoka City, Shizuoka 422‐8526 (Japan); Watanabe, Tatsuo [Laboratory of Food Chemistry, School of Food and Nutritional Sciences, University of Shizuoka, 52‐1 Yada, Suruga-ku, Shizuoka City, Shizuoka 422‐8526 (Japan); Imai, Yasuyuki, E-mail: imai@u-shizuoka-ken.ac.jp [Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, 52‐1 Yada, Suruga-ku, Shizuoka City, Shizuoka 422‐8526 (Japan)

2012-11-01

Some chemicals contribute to the development of allergies by increasing the immunogenicity of other allergens. We have demonstrated that several phthalate esters, including dibutyl phthalate (DBP), enhance skin sensitization to fluorescein isothiocyanate (FITC) in a mouse contact hypersensitivity model, in which the T-helper type 2 (Th2) response is essential. On the other hand, some phthalate esters were found to activate transient receptor potential ankyrin 1 (TRPA1) cation channels on sensory neurons. We then found a positive correlation between the enhancing effects of several types of phthalate esters on skin sensitization to FITC and their ability to activate TRPA1. Here we examined the involvement of TRPA1 in sensitization to FITC by using TRPA1 agonists other than phthalate esters. During skin sensitization to FITC, the TRPA1 agonists (menthol, carvacrol, cinnamaldehyde and DBP) augmented the ear-swelling response as well as trafficking of FITC-presenting dendritic cells to draining lymph nodes. We confirmed that these TRPA1 agonists induced calcium influx into TRPA1-expressing Chinese hamster ovary (CHO) cells. We also found that TRPA1 antagonist HC-030031 inhibited DBP-induced calcium influx into TRPA1-expressing CHO cells. After pretreatment with this antagonist upon skin sensitization to FITC, the enhancing effect of DBP on sensitization was suppressed. These results suggest that TRPA1 activation will become a useful marker to find chemicals that facilitate sensitization in combination with other immunogenic haptens. -- Highlights: ► Role of TRPA1 activation was revealed in a mouse model of skin sensitization to FITC. ► TRPA1 agonists enhanced skin sensitization as well as dendritic cell trafficking. ► Dibutyl phthalate (DBP) has been shown to enhance skin sensitization to FITC. ► TRPA1 activation by DBP was inhibited by a selective antagonist, HC-030031. ► HC-030031 inhibited the enhancing effect of DBP on skin sensitization to FITC.

[Nursing care in fluorescein angiography].

Science.gov (United States)

Santos-Blanco, Feliciano

2008-01-01

Fluoresceinic angiography of the ocular fundus is a diagnostic technique to study retinal and choroidal circulation. This technique consists of parenteral administration of 500 mg of sodium fluorescein 10% and photographing the fluorescence in the eye vessels. Although this substance is fairly safe, it may also produce mild, moderate or severe local and/or general adverse reactions. The nursing process is routinely used in hospital units but not always in outpatient clinics, even through the use of invasive procedures with intravenous medication administration is common. Therefore, nurses, as those reponsible for intravenous administration, should use the nursing process to guarantee the quality of care required by the patient. To do this, we describe an individualized care plan based on evaluation by Marjorie Gordon's functional health patterns, NANDA's nursing diagnoses Taxonomy II, Nursing Outcomes Classification (NOC), Nursing Interventions Classifications (NIC) and potential complications of the procedure.

Peptide Reactivity of Isothiocyanates - Implications for Skin Allergy

Science.gov (United States)

Karlsson, Isabella; Samuelsson, Kristin; Ponting, David J.; Törnqvist, Margareta; Ilag, Leopold L.; Nilsson, Ulrika

2016-02-01

Skin allergy is a chronic condition that affects about 20% of the population of the western world. This disease is caused by small reactive compounds, haptens, able to penetrate into the epidermis and modify endogenous proteins, thereby triggering an immunogenic reaction. Phenyl isothiocyanate (PITC) and ethyl isothiocyanate (EITC) have been suggested to be responsible for allergic skin reactions to chloroprene rubber, the main constituent of wetsuits, orthopedic braces, and many types of sports gear. In the present work we have studied the reactivity of the isothiocyanates PITC, EITC, and tetramethylrhodamine-6-isothiocyanate (6-TRITC) toward peptides under aqueous conditions at physiological pH to gain information about the types of immunogenic complexes these compounds may form in the skin. We found that all three compounds reacted quickly with cysteine moieties. For PITC and 6-TRITC the cysteine adducts decomposed over time, while stable adducts with lysine were formed. These experimental findings were verified by DFT calculations. Our results may suggest that the latter are responsible for allergic reactions to isothiocyanates. The initial adduct formation with cysteine residues may still be of great importance as it prevents hydrolysis and facilitates the transport of isothiocyanates into epidermis where they can form stable immunogenic complexes with lysine-containing proteins.

Optimized Formation of Benzyl Isothiocyanate by Endogenous ...

African Journals Online (AJOL)

The formed benzyl isothiocyanate was extracted by steam distillation method and purified by thin-layer chromatography (TLC). Relevant process variables were also studied. Finally, the purified benzyl isothiocyanate was analyzed by gas chromatography-mass spectrometer (GC-MS) and compared to BITC standard.

CancerLectinDB: a database of lectins relevant to cancer.

Science.gov (United States)

Damodaran, Deepa; Jeyakani, Justin; Chauhan, Alok; Kumar, Nirmal; Chandra, Nagasuma R; Surolia, Avadhesha

2008-04-01

The role of lectins in mediating cancer metastasis, apoptosis as well as various other signaling events has been well established in the past few years. Data on various aspects of the role of lectins in cancer is being accumulated at a rapid pace. The data on lectins available in the literature is so diverse, that it becomes difficult and time-consuming, if not impossible to comprehend the advances in various areas and obtain the maximum benefit. Not only do the lectins vary significantly in their individual functional roles, but they are also diverse in their sequences, structures, binding site architectures, quaternary structures, carbohydrate affinities and specificities as well as their potential applications. An organization of these seemingly independent data into a common framework is essential in order to achieve effective use of all the data towards understanding the roles of different lectins in different aspects of cancer and any resulting applications. An integrated knowledge base (CancerLectinDB) together with appropriate analytical tools has therefore been developed for lectins relevant for any aspect of cancer, by collating and integrating diverse data. This database is unique in terms of providing sequence, structural, and functional annotations for lectins from all known sources in cancer and is expected to be a useful addition to the number of glycan related resources now available to the community. The database has been implemented using MySQL on a Linux platform and web-enabled using Perl-CGI and Java tools. Data for individual lectins pertain to taxonomic, biochemical, domain architecture, molecular sequence and structural details as well as carbohydrate specificities. Extensive links have also been provided for relevant bioinformatics resources and analytical tools. Availability of diverse data integrated into a common framework is expected to be of high value for various studies on lectin cancer biology. CancerLectinDB can be accessed through

Lectin-Array Blotting.

Science.gov (United States)

Pazos, Raquel; Echevarria, Juan; Hernandez, Alvaro; Reichardt, Niels-Christian

2017-09-01

Aberrant protein glycosylation is a hallmark of cancer, infectious diseases, and autoimmune or neurodegenerative disorders. Unlocking the potential of glycans as disease markers will require rapid and unbiased glycoproteomics methods for glycan biomarker discovery. The present method is a facile and rapid protocol for qualitative analysis of protein glycosylation in complex biological mixtures. While traditional lectin arrays only provide an average signal for the glycans in the mixture, which is usually dominated by the most abundant proteins, our method provides individual lectin binding profiles for all proteins separated in the gel electrophoresis step. Proteins do not have to be excised from the gel for subsequent analysis via the lectin array but are transferred by contact diffusion from the gel to a glass slide presenting multiple copies of printed lectin arrays. Fluorescently marked glycoproteins are trapped by the printed lectins via specific carbohydrate-lectin interactions and after a washing step their binding profile with up to 20 lectin probes is analyzed with a fluorescent scanner. The method produces the equivalent of 20 lectin blots in a single experiment, giving detailed insight into the binding epitopes present in the fractionated proteins. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

The galactophilic lectin (PA-IL, gene LecA) from Pseudomonas aeruginosa. Its binding requirements and the localization of lectin receptors in various mouse tissues

DEFF Research Database (Denmark)

Kirkeby, Svend; Hansen, Axel K; d'Apice, Anthony

2006-01-01

. aeruginosa lectin were compared with the results obtained using an isolectin from the legume shrub Griffonia simplicifolia: the GSI-134 isolectin, which is highly specific for glycans terminating in Ga1 alpha 1-R. In the wild-type mice, lectin histochemistry showed a strong capillary reaction in heart...

Microglial Lectins in Health and Neurological Diseases

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Jian Jing Siew

2018-05-01

Full Text Available Microglia are the innate sentinels of the central nervous system (CNS and are responsible for the homeostasis and immune defense of the CNS. Under the influence of the local environment and cell-cell interaction, microglia exhibit a multidimensional and context-dependent phenotypes that can be cytotoxic and neuroprotective. Recent studies suggest that microglia express multitudinous types of lectins, including galectins, Siglecs, mannose-binding lectins (MBLs and other glycan binding proteins. Because most studies that examine lectins focus on the peripheral system, the functions of lectins have not been critically investigated in the CNS. In addition, the types of brain cells that contribute to the altered levels of lectins present in diseases are often unclear. In this review, we will discuss how galectins, Siglecs, selectins and MBLs contribute to the dynamic functions of microglia. The interacting ligands of these lectins are complex glycoconjugates, which consist of glycoproteins and glycolipids that are expressed on microglia or surrounding cells. The current understanding of the heterogeneity and functions of glycans in the brain is limited. Galectins are a group of pleotropic proteins that recognize both β-galactoside-containing glycans and non- β-galactoside-containing proteins. The function and regulation of galectins have been implicated in immunomodulation, neuroinflammation, apoptosis, phagocytosis and oxidative bursts. Most Siglecs are expressed at a low level on the plasma membrane and bind to sialic acid residues for immunosurveillance and cell-cell communication. Siglecs are classified based on their inhibitory and activatory downstream signaling properties. Inhibitory Siglecs negatively regulate microglia activation upon recognizing the intact sialic acid patterns and vice versa. MBLs are expressed upon infection in cytoplasm and can be secreted in order to recognize molecules containing terminal mannose as an innate immune

[Lectins, adhesins, and lectin-like substances of lactobacilli and bifidobacteria].

Science.gov (United States)

Lakhtin, V M; Aleshkin, V A; Lakhtin, M V; Afanas'ev, S S; Pospelova, V V; Shenderov, B A

2006-01-01

Cell-surface adhesion factors of lactobacilli and bifidobacteria, such as lectin/adhesin proteins of S-layers, secreted lectin-like bacteriocins, and lectin-like complexes, are considered and classified in the article. Certain general and specific properties of these factors are noted, such as in vitro and in vivo adhesion, cell co(aggregation), participation in the forming of microbial biofilms and colonization of mammalian alimentary tract, as well as complexation with biopolymers and bioeffectors, specificity to glycanes and natural glycoconjugates, domain and spatial organization of adhesion factors, co-functioning with other cytokines (pro- and anti-inflammatory ones), regulation of target cell properties, and other biological and physiological activities. The authors also note possibilities of application of lectins and lectin-like proteins of probiotic strains of lactobacilli and bifidobacteria in medicine and biotechnology.

Lectins with Anti-HIV Activity: A Review

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Ouafae Akkouh

2015-01-01

Full Text Available Lectins including flowering plant lectins, algal lectins, cyanobacterial lectins, actinomycete lectin, worm lectins, and the nonpeptidic lectin mimics pradimicins and benanomicins, exhibit anti-HIV activity. The anti-HIV plant lectins include Artocarpus heterophyllus (jacalin lectin, concanavalin A, Galanthus nivalis (snowdrop agglutinin-related lectins, Musa acuminata (banana lectin, Myrianthus holstii lectin, Narcissus pseudonarcissus lectin, and Urtica diocia agglutinin. The anti-HIV algal lectins comprise Boodlea coacta lectin, Griffithsin, Oscillatoria agardhii agglutinin. The anti-HIV cyanobacterial lectins are cyanovirin-N, scytovirin, Microcystis viridis lectin, and microvirin. Actinohivin is an anti-HIV actinomycete lectin. The anti-HIV worm lectins include Chaetopterus variopedatus polychaete marine worm lectin, Serpula vermicularis sea worm lectin, and C-type lectin Mermaid from nematode (Laxus oneistus. The anti-HIV nonpeptidic lectin mimics comprise pradimicins and benanomicins. Their anti-HIV mechanisms are discussed.

Lectin typing of Campylobacter concisus

DEFF Research Database (Denmark)

Aabenhus, Rune Munck; Hynes, Sean O; Permin, Henrik

2002-01-01

A total of 44 clinical isolates and the type strain of the putative pathogen Campylobacter concisus were grouped based on their reactions with plant lectins. The optimized lectin typing system used C. concisus strains proteolytically pretreated and subsequently typed by using a panel of four...... lectins. The system grouped all 45 strains into 13 lectin reaction patterns, leaving no strain untypeable due to autoagglutination. Lectin types were both stable and reproducible....

Stable, water extractable isothiocyanates from Moringa oleifera leaves attenuate inflammation in vitro.

Science.gov (United States)

Waterman, Carrie; Cheng, Diana M; Rojas-Silva, Patricio; Poulev, Alexander; Dreifus, Julia; Lila, Mary Ann; Raskin, Ilya

2014-07-01

Moringa (Moringa oleifera Lam.) is an edible plant used as both a food and medicine throughout the tropics. A moringa concentrate (MC), made by extracting fresh leaves with water, utilized naturally occurring myrosinase to convert four moringa glucosinolates into moringa isothiocyanates. Optimum conditions maximizing MC yield, 4-[(α-L-rhamnosyloxy)benzyl]isothiocyanate, and 4-[(4'-O-acetyl-α-L-rhamnosyloxy)benzyl]isothiocyanate content were established (1:5 fresh leaf weight to water ratio at room temperature). The optimized MC contained 1.66% isothiocyanates and 3.82% total polyphenols. 4-[(4'-O-acetyl-α-L-rhamnosyloxy)benzyl]isothiocyanate exhibited 80% stability at 37°C for 30 days. MC, and both of the isothiocyanates described above significantly decreased gene expression and production of inflammatory markers in RAW macrophages. Specifically, both attenuated expression of iNOS and IL-1β and production of nitric oxide and TNFα at 1 and 5 μM. These results suggest a potential for stable and concentrated moringa isothiocyanates, delivered in MC as a food-grade product, to alleviate low-grade inflammation associated with chronic diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Histochemical analysis of glycoconjugates in the skin of a catfish (arius tenuispinis, day).

Science.gov (United States)

Al-Banaw, A; Kenngott, R; Al-Hassan, J M; Mehana, N; Sinowatz, F

2010-02-01

A histochemical study using conventional carbohydrate histochemistry (periodic-acid staining including diastase controls, alcian blue staining at pH 1 and 2.5) as well as using a battery of 14 fluorescein isothiocyanate (FITC)-labelled lectins to identify glycoconjugates present in 10 different areas of the skin of a catfish (Arius tenuispinis) was carried out. The lectins used were: mannose-binding lectins (Con A, LCA and PSA), galactose-binding lectins (PNA, RCA), N-acetylgalactosamine-binding lectins (DBA, SBA, SJA and GSL I), N-acetylglucosamine-binding lectins (WGA and WGAs), fucose-binding lectins (UEA) and lectins which bind to complex carbohydrate configurations (PHA E, PHA L). Conventional glycoconjugate staining (PAS staining, alcian blue at pH 1 and 2.5) showed that the mucous goblet cells contain a considerable amount of glycoconjugates in all locations of the skin, whereas the other unicellular gland type, the club cells, lacked these glycoconjugates. The glycoproteins found in goblet cells are neutral and therefore stain magenta when subjected to PAS staining. Alcian blue staining indicating acid glycoproteins was distinctly positive at pH 1, but gave only a comparable staining at pH 2.5. The mucus of the goblet cells therefore also contains acid glycoproteins rich in sulphate groups. Using FITC-labelled lectins, the carbohydrate composition of the glycoproteins of goblet cells could be more fully characterized. A distinct staining of the mucus of goblet cells was found with the mannose-binding lectins LCA and PSA; the galactosamine-binding lectins DBA, SBA and GLS I; the glucosamine-binding lectin WGA; and PHA E which stains glycoproteins with complex carbohydrate configurations. No reaction occurred with the fucose-binding lectin UEA and the sialic acid-specific lectin SNA. In addition, the galactose-binding lectins PNA and RCA showed only a weak or completely negative staining of the mucus in the goblet cells. The specificity of the lectin staining

Antimicrobial Activity of Isothiocyanates from Cruciferous Plants against Methicillin-Resistant Staphylococcus aureus (MRSA

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Carla Dias

2014-10-01

Full Text Available Purified isothiocyanates from cruciferous plants (Brassicacea, Syn. Cruciferae plants were evaluated against 15 isolates of methicillin-resistant S. aureus isolated from diabetic foot-ulcer patients aiming the study of the potential usage of allyl-isothiocyanate, benzyl-isothiocyanate and 2-phenylethyl-isothiocyanate against this important bacteria. Disc diffusion and minimum inhibitory concentration methods were used to access the antimicrobial activity. The index (Ia and rate (Ra of the antibacterial activity for each compound were calculated. The results showed a highly dose-dependent compound and chemical structure antibacterial effectiveness. The results showed a strong relation between the chemical structure of isothiocyanates and its antibacterial effectiveness. The benzyl-isothiocyanate was the most effective with a minimum inhibitory concentration varying between 2.9 and 110 µg·mL−1 with an antibacterial activity rate up to 87%. Moreover, their antibacterial activity was mainly bactericidal. This study provides scientific evidence that isothiocyanates have an interesting biological value and must be considered as an important tool to be used against MRSA.

The rapid generation of isothiocyanates in flow

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Marcus Baumann

2013-08-01

Full Text Available Isothiocyanates are versatile starting materials for a wide range of chemical reactions. However, their high nucleophilic susceptibility means they are best prepared and used immediately. We report here on a flow platform for the fast and efficient formation of isothiocyanates by the direct conversion of easily prepared chloroximes. To expedite this chemistry a flow insert cartridge containing two immobilised reagents is used to affect the chemical transformation which typically eliminates the requirements for any conventional work-up or purification of the reaction stream.

Accidental intra-arterial injection of fluorescein dye.

Science.gov (United States)

Bovino, J A; Marcus, D F

1984-12-01

During fluorescein angiography, sodium fluorescein dye intended for intravenous use was inadvertently injected into an artery in the antecubital fossa. An immediate and dramatic orange discoloration of the skin distal to the injection combined with intense burning pain of the right forearm and hand were noted. The patient was treated with ice packs and analgesics. The fluorescein angiogram showed a delayed arm to eye circulation time, but was of normal quality. There were no long-term complications.

IDENTIFICATION OF LECTINS OF ZEA MAYS RAW MATERIAL AND THE STUDY OF LECTIN ACTIVITY

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Karpiuk UV

2013-03-01

Full Text Available The aime of the study was to identify lectins in the Zea mays raw material: roots, stems, heads, leaves and corn silk and study their activity. Lectins activity has been studied using the biological method of ratuserytroagglutination. This method is based on formation of aggregates of lectins and rats erythrocytes. The activity unit was the floor amount of lectins that agglutinate erythrocytes. The protein nature of extracts that agglutinate has been determined using Bradford method. The lectins activity of Zea mays roots was 6,21±0,11 unit/mg of protein; of heads – 2,61±0,17 unit/mg of protein; of leaves – 0,62 ±0,05 unit/mg of protein; of corn silk – 1,06±0,08 unit/mg of protein; of stems – 0,97±0,09 unit/mg of protein. The greatest lectins activity was in leaves, stems and corn silk.

Lectins in human pathogenic fungi.

Science.gov (United States)

Gallegos, Belém; Martínez, Ruth; Pérez, Laura; Del Socorro Pina, María; Perez, Eduardo; Hernández, Pedro

2014-01-01

Lectins are carbohydrate-binding proteins widely distributed in nature. They constitute a highly diverse group of proteins consisting of many different protein families that are, in general, structurally unrelated. In the last few years, mushroom and other fungal lectins have attracted wide attention due to their antitumour, antiproliferative and immunomodulatory activities. The present mini-review provides concise information about recent developments in understanding lectins from human pathogenic fungi. A bibliographic search was performed in the Science Direct and PubMed databases, using the following keywords "lectin", "fungi", "human" and "pathogenic". Lectins present in fungi have been classified; however, the role played by lectins derived from human pathogenic fungi in infectious processes remains uncertain; thus, this is a scientific field requiring more research. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Glycans: bioactive signals decoded by lectins.

Science.gov (United States)

Gabius, Hans-Joachim

2008-12-01

The glycan part of cellular glycoconjugates affords a versatile means to build biochemical signals. These oligosaccharides have an exceptional talent in this respect. They surpass any other class of biomolecule in coding capacity within an oligomer (code word). Four structural factors account for this property: the potential for variability of linkage points, anomeric position and ring size as well as the aptitude for branching (first and second dimensions of the sugar code). Specific intermolecular recognition is favoured by abundant potential for hydrogen/co-ordination bonds and for C-H/pi-interactions. Fittingly, an array of protein folds has developed in evolution with the ability to select certain glycans from the natural diversity. The thermodynamics of this reaction profits from the occurrence of these ligands in only a few energetically favoured conformers, comparing favourably with highly flexible peptides (third dimension of the sugar code). Sequence, shape and local aspects of glycan presentation (e.g. multivalency) are key factors to regulate the avidity of lectin binding. At the level of cells, distinct glycan determinants, a result of enzymatic synthesis and dynamic remodelling, are being defined as biomarkers. Their presence gains a functional perspective by co-regulation of the cognate lectin as effector, for example in growth regulation. The way to tie sugar signal and lectin together is illustrated herein for two tumour model systems. In this sense, orchestration of glycan and lectin expression is an efficient means, with far-reaching relevance, to exploit the coding potential of oligosaccharides physiologically and medically.

Comparative Study of Lectin Domains in Model Species: New Insights into Evolutionary Dynamics

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Sofie Van Holle

2017-05-01

Full Text Available Lectins are present throughout the plant kingdom and are reported to be involved in diverse biological processes. In this study, we provide a comparative analysis of the lectin families from model species in a phylogenetic framework. The analysis focuses on the different plant lectin domains identified in five representative core angiosperm genomes (Arabidopsis thaliana, Glycine max, Cucumis sativus, Oryza sativa ssp. japonica and Oryza sativa ssp. indica. The genomes were screened for genes encoding lectin domains using a combination of Basic Local Alignment Search Tool (BLAST, hidden Markov models, and InterProScan analysis. Additionally, phylogenetic relationships were investigated by constructing maximum likelihood phylogenetic trees. The results demonstrate that the majority of the lectin families are present in each of the species under study. Domain organization analysis showed that most identified proteins are multi-domain proteins, owing to the modular rearrangement of protein domains during evolution. Most of these multi-domain proteins are widespread, while others display a lineage-specific distribution. Furthermore, the phylogenetic analyses reveal that some lectin families evolved to be similar to the phylogeny of the plant species, while others share a closer evolutionary history based on the corresponding protein domain architecture. Our results yield insights into the evolutionary relationships and functional divergence of plant lectins.

Effect of allyl isothiocyanate on developmental toxicity in exposed Xenopus laevis embryos

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John Russell Williams

2015-01-01

Full Text Available The pungent natural compound allyl isothiocyanate isolated from the seeds of Cruciferous (Brassica plants such as mustard is reported to exhibit numerous beneficial health-promoting antimicrobial, antifungal, anticarcinogenic, cardioprotective, and neuroprotective properties. Because it is also reported to damage DNA and is toxic to aquatic organisms, the objective of the present study was to determine whether it possesses teratogenic properties. The frog embryo teratogenesis assay-Xenopus (FETAX was used to determine the following measures of developmental toxicity of the allyl isothiocyanate: (a 96-h LC50, defined as the median concentration causing 50% embryo lethality; (b 96-h EC50, defined as the median concentration causing 50% malformations of the surviving embryos; and (c teratogenic malformation index (TI, equal to 96-h LC50/96-h EC50. The quantitative results and the photographs of embryos before and after exposure suggest that allyl isothiocyanate seems to exhibit moderate teratogenic properties. The results also indicate differences in the toxicity of allyl isothiocyanate toward exposed embryos observed in the present study compared to reported adverse effects of allyl isothiocyanate in fish, rodents, and humans. The significance of the results for food safety and possible approaches to protect against adverse effects of allyl isothiocyanate are discussed.

Lectin affinity electrophoresis.

Science.gov (United States)

Kobayashi, Yuka

2014-01-01

An interaction or a binding event typically changes the electrophoretic properties of a molecule. Affinity electrophoresis methods detect changes in the electrophoretic pattern of molecules (mainly macromolecules) that occur as a result of biospecific interactions or complex formation. Lectin affinity electrophoresis is a very effective method for the detection and analysis of trace amounts of glycobiological substances. It is particularly useful for isolating and separating the glycoisomers of target molecules. Here, we describe a sensitive technique for the detection of glycoproteins separated by agarose gel-lectin affinity electrophoresis that uses antibody-affinity blotting. The technique is tested using α-fetoprotein with lectin (Lens culinaris agglutinin and Phaseolus vulgaris agglutinin)-agarose gels.

Biological role of lectins: A review

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K Kiran Kumar

2012-01-01

Full Text Available Lectins comprise a stracturally vary diverse class of proteins charecterized by their ability to selectively bind carbohydrate moieties of the glycoproteins of the cell surface. Lectins may be derived from plants, microbial or animal sources and may be soluble or membrane bound. Lectins is a tetramer made up of four nearly identical subunits. In human, lectins have been reported to cause food poisoning, hemolytic anemia, jaundice, digestive distress, protein and carbohydrate malabsorption and type I allergies. The present review focuses on the classification, structures, biological significance and application of lectins.

Simple Improvisation to Enhance Utility of Fluorescein Sodium in Resection of Intracranial Lesions at Routine Neurosurgical Centers.

Science.gov (United States)

Gollapudi, Prakash Rao; Mohammed, Imran; Pittala, Sandeep R; Kotha, Arjun Reddy; Reddycherla, Naga Raju; Ginjupally, Dhanunjaya Rao

2018-04-01

Fluorescein sodium is one of the fluorophores that is used in the resection of intracranial lesions. It is commonly used along with a customized microscope, which is expensive and not available universally. In this study, we describe a simple, inexpensive method for better visualization of intracranial and spinal cord lesions with fluorescein. After a test dose, 20 mg/kg of fluorescein sodium was administered intravenously at the time of intubation. A blue light source was used before resection for precise localization of the intracranial lesions after durotomy. Most of the resection was done under the white light, while the blue light was used intermittently to delineate the pathologic tissue from the normal tissue and to ensure safe maximal resection. The intensity of fluorescein staining under white light and blue light was noted. The study comprised 40 cases of gliomas, meningiomas, abscesses, spinal cord tumors, and cerebellopontine angle lesions. Thirty-five lesions showed good fluorescence under the blue light, which helped us achieve better resection of the pathologic lesions. Fluorescein sodium is a safe dye; it can be used to aid in precise localization and safe maximal resection of the pathologic tissue with the help of a blue light source at any center with challenged resources. The blue light enhances the fluorescence and visualization of the pathologic tissue, and this technique can be adopted by any surgeon without much difficulty even with a basic neurosurgical setup. Copyright © 2018 Elsevier Inc. All rights reserved.

Fluorescein angiogram in diabetic dogs

International Nuclear Information System (INIS)

Ono, K.; Yasuda, K.; Iwata, H.; Nakayama, H.; Hasegawa, A.; Tomoda, I.

1986-01-01

Fluorescein angiography was carried out see retinal vascular changes of the ocular fundus in 4 spontaneously occurring diabetic dogs. In all 4 cases, several hypofluorescent areas were determined to be filling defects of the retinal capillary bed of the tapetal fundi during the arteriovenous phase. Around these hypofluorescent areas, many dots of hyperfluorescence were also observed to be microaneurysms. However, no leaking of fluorescein was detected during angiography. These findings of 4 diabetic dogs were similar to those reported in man with non-proliferative diabetic retinopathy

A new method of lectin histochemistry for the study of brain angiogenesis. Lectin angiography.

Science.gov (United States)

Minamikawa, T; Miyake, T; Takamatsu, T; Fujita, S

1987-01-01

In an attempt to analyse the kinetics of angiogenesis in the brain, we developed a new lectin-histochemical staining technique for identifying the vasculature. Three horseradish-peroxidase-conjugated lectins, i.e., Griffonia simplicifolia agglutinin 1 (GS1), Ricinus communis agglutinin 1 (RCA1) and soybean agglutinin (SBA), selectively stained vascular walls in brain-tissue sections. When these lectins were injected into the circulation of ether-anesthetized animals via the pulsating left ventricle, they bound specifically to the inner surface of endothelial cells and revealed the three-dimensional architecture of the vascular network within thick tissue preparations. When this technique, referred to a lectin angiography, was combined with 5-bromo-2-deoxyuridine (BudR) immunohistochemistry, proliferating capillary cells could be easily identified in three-dimensional structures of the developing vasculature. Because of its simplicity and wide applicability, lectin angiography should be useful for analysing the kinetics of angiogenesis in developmental, regenerative, and pathological conditions in various tissues and organs.

Studies of the endothelial origin of cells in systemic angioendotheliomatosis and other vascular lesions of the brain and meninges using ulex europaeus lectin stains.

Science.gov (United States)

Schelper, R L; Olson, S P; Carroll, T J; Hart, M N; Witters, E

1986-01-01

Ulex europaeus agglutinin I (UEA-I) is a plant lectin which binds specifically to alpha-L-fucose moieties on the surface glycoproteins of human endothelial cells. The binding is completely inhibited by preincubation of the lectin with fucose. UEA-I can be conjugated directly to fluorescein or peroxidase and can be used to stain endothelium of paraffin embedded tissues. UEA-I staining was evaluated on normal and infarcted brain, systemic angioendotheliomatosis, metastatic epidural angiosarcoma, hemangioendothelioma, hemangioblastoma, angioblastic meningioma of both the hemangioblastic and hemangiopericytic types, and vascular meningioma. The endothelium, but not neuropil of normal and infarcted brain was positive for UEA-I. The tumor cells of hemangioendothelioma and angiosarcoma also stained. However, no staining was seen in malignant intravascular cells of angioendotheliomatosis, the stromal cells of hemangioblastoma, or pericytes of angioblastic meningioma. It is concluded that the malignant cells in angioendotheliomatosis, the stromal cells of hemangioblastoma and the pericytes of angioblastic meningioma do not produce surface glycoproteins characteristic of endothelial cells.

Recent Progress in Lectin-Based Biosensors

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Baozhen Wang

2015-12-01

Full Text Available This article reviews recent progress in the development of lectin-based biosensors used for the determination of glucose, pathogenic bacteria and toxins, cancer cells, and lectins. Lectin proteins have been widely used for the construction of optical and electrochemical biosensors by exploiting the specific binding affinity to carbohydrates. Among lectin proteins, concanavalin A (Con A is most frequently used for this purpose as glucose- and mannose-selective lectin. Con A is useful for immobilizing enzymes including glucose oxidase (GOx and horseradish peroxidase (HRP on the surface of a solid support to construct glucose and hydrogen peroxide sensors, because these enzymes are covered with intrinsic hydrocarbon chains. Con A-modified electrodes can be used as biosensors sensitive to glucose, cancer cells, and pathogenic bacteria covered with hydrocarbon chains. The target substrates are selectively adsorbed to the surface of Con A-modified electrodes through strong affinity of Con A to hydrocarbon chains. A recent topic in the development of lectin-based biosensors is a successful use of nanomaterials, such as metal nanoparticles and carbon nanotubes, for amplifying output signals of the sensors. In addition, lectin-based biosensors are useful for studying glycan expression on living cells.

Assessing biosafety of GM plants containing lectins

DEFF Research Database (Denmark)

Poulsen, Morten; Pedersen, Jan W.

2010-01-01

insects. However, since the cry genes are not active against all insects, e.g. sap-sucking insects, other genes coding for proteins such as lectins show promise of complementing the cry genes for insect resistance. As with other novel plants, lectin-expressing plants will need to be assessed...... for their potential risks to human and animal health and the environment. The expressed lectin protein should be assessed on its own for potential toxicity and allergenicity as for any other new protein. Although not many lectins have been thoroughly tested for their toxicity, our evaluation suggests that most...... of the lectins that are potentially useful for insect resistance will pose no health risk in genetically modified (GM) plants. Since some lectins are known for their toxicity to humans, the insertion of lectin genes in food crop plants will have to be assessed carefully. It is expected that in some cases...

The lectin pathway of complement

DEFF Research Database (Denmark)

Ballegaard, Vibe Cecilie Diederich; Haugaard, Anna Karen; Garred, P

2014-01-01

The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2......-1, -2 and -3 and CL-11 could have similar functions in HIV infection as the ficolins have been shown to play a role in other viral infections, and CL-11 resembles MBL and the ficolins in structure and binding capacity.......The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2...

Lectins and their application to clinical microbiology.

OpenAIRE

Slifkin, M; Doyle, R J

1990-01-01

Lectins are generally associated with plant or animal components, selectively bind carbohydrates, and interact with procaryotic and eucaryotic cells. Lectins have various specificities that are associated with their ability to interact with acetylaminocarbohydrates, aminocarbohydrates, sialic acids, hexoses, pentoses, and as other carbohydrates. Microbial surfaces generally contain many of the sugar residues that react with lectins. Lectins are presently used in the clinical laboratory to typ...

Immunogold study on lectin binding in the porcine zona pellucida and granulosa cells

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F Parillo

2009-06-01

Full Text Available An ultrastructural localization of lectin receptors on the zona pellucida (ZP of porcine antral oocytes and on the granulosa cells was performed using a panel of horseradish peroxidase- labelled lectins in conjunction with antiperoxidase antibody and protein A-gold. In some cases, lectin incubation was preceded by sialidase digestion. WGA-, Con-A-, UEA-I-, RCA-I-, PNA- and SBA-reactive sites were distributed differently in the porcine ZP. Sialidase digestion increased the positivity obtained with RCA-I and it was necessary to promote PNA and SBA reactivity. These results indicated that the ZP contained N-acetylglucosamine, a-mannose, a- fucose, b-Gal-(1-4GlcNAc, b-Gal- (1-3GalNAc, b-GalNAc and sialic acid residues. We also observed the presence of vesicles in both the ooplasm and granulosa cells, showing a similar lectin binding pattern to that of the ZP, thus suggesting that the oocyte and granulosa cells are the site of synthesis of ZP glucidic determinants.

Glucosinolates and isothiocyanates from broccoliseed extractsuppressproteinglycationand carbonylation

Directory of Open Access Journals (Sweden)

Marina Hirano,

2018-01-01

Full Text Available Background: Glucosinolates from brassica plants are hydrolyzed by internal or salivary myrosinase to produce isothiocyanates. Glucoraphanin, a major glucosinolate in broccoli, is hydrolyzed to sulforaphane (SFN, which exhibits antitumor and detoxification activities. Regarding the influence of broccoli and its constituents on the skin, a few studies have reported anti-inflammatory and antioxidant effects. Recently, advanced glycation end products (AGEs and carbonyl proteins have been reported to accelerate skin aging. Objective: We evaluated the effects of broccoli seed extract (BSE and glucosinolates on protein glycation and carbonylation in vitro. Methods: To evaluate the effects of BSE and its constituents, protein glycation and carbonylation were induced by mixing fructose with bovine serum albumin (BSA and then measuring production of AGEs, fructosamine, and carbonyl proteins (CP. Production of CP after mixing fatty acids with BSA was also assessed. Furthermore, the effect of BSE and its constituents on CP production by human fibroblasts (TIG103 was examined. Results: BSE suppressed the production of AGEs, fructosamine, and CP after mixing fructose and BSA. BSE also suppressed production of CP when oxidized linoleic acid was mixed with BSA. Isothiocyanates, including SFN and iberin, suppressed fructose-based CP production, but SFN had no effect on CP production stimulated by oxidized linoleic acid. In contrast, glucosinolates from BSE did not suppress fructose-based CP production, but suppressed CP production due to oxidized linoleic acid. Among the glucosinolates in BSE, glucoberteroin showed the strongest suppression of CP production. CP production in fibroblasts was also suppressed by glucosinolates, including glucoiberin and glucoberteroin. Conclusions: BSE demonstrated anti-glycation and anti-carbonylation effects on protein reactions with fructose and oxidized fatty acids. Isothiocyanates suppressed protein carbonylation induced by

Characterization and antimicrobial activity of lectins from Penicillium sp.

Science.gov (United States)

Singh, R S; Jain, P; Kaur, H P

2013-11-01

Ten Penicillium sp. were screened for lectin activity for occurrence of lectins. Mycelial extracts from submerged cultures of P. corylophilum, P. expansum and P. purpurogenum showed agglutination against human (A, B, AB and O), goat, sheep, pig and rabbit erythrocytes. Neuraminidase treatment to human blood- type O erythrocytes substantially increased their agglutinability by all the lectins as compared to untreated erythrocytes. Modification of erythrocyte surfaces by protease increased the lectin titre only of P. corylophilum with no effect on other two lectins. P. corylophilum and P. expansum displayed relatively lower titres in mycelial extracts prepared from agar plate cultures as compared to broth cultures. A panel of sugars was tested for inhibition of lectin activity. All the lectins were found to be specific for asialofetuin, bovine submaxillary mucin, porcine stomach mucin, chondroitin-6-sulphate, D-sucrose and D-glucose. P. corylophilum lectin was expressed (Titre 8) by 5 day old cultures, reaching its maximum level (Titre 32) upon 8 days of cultivation, thereafter declin in lectin activity was observed. P. purpurogenum lectin was expressed by 7-10 days old cultures, while in P. expansum maximum lectin activity was elaborated by 5-8 days old cultures. Lectin extracts from all the three species were found to possess antimicrobial activities. Lectin extracts from the three Penicillium species displayed antifungal activity and antibacterial activity against Gram-negative and Gram-positive bacterial strains.

Dietary isothiocyanate sulforaphene induces reactive oxygen ...

African Journals Online (AJOL)

Purpose: To investigate the apoptotic activity, cell proliferation inhibition and different signaling protein expressions after treatment with a new isothiocyanate, sulforaphene, in human cervical cancer (HeLa) cells. Methods: Cytotoxicity was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay ...

An investigation of paper based microfluidic devices for size based separation and extraction applications.

Science.gov (United States)

Zhong, Z W; Wu, R G; Wang, Z P; Tan, H L

2015-09-01

Conventional microfluidic devices are typically complex and expensive. The devices require the use of pneumatic control systems or highly precise pumps to control the flow in the devices. This work investigates an alternative method using paper based microfluidic devices to replace conventional microfluidic devices. Size based separation and extraction experiments conducted were able to separate free dye from a mixed protein and dye solution. Experimental results showed that pure fluorescein isothiocyanate could be separated from a solution of mixed fluorescein isothiocyanate and fluorescein isothiocyanate labeled bovine serum albumin. The analysis readings obtained from a spectrophotometer clearly show that the extracted tartrazine sample did not contain any amount of Blue-BSA, because its absorbance value was 0.000 measured at a wavelength of 590nm, which correlated to Blue-BSA. These demonstrate that paper based microfluidic devices, which are inexpensive and easy to implement, can potentially replace their conventional counterparts by the use of simple geometry designs and the capillary action. These findings will potentially help in future developments of paper based microfluidic devices. Copyright © 2015 Elsevier B.V. All rights reserved.

A Lectin from Dioclea violacea Interacts with Midgut Surface of Lutzomyia migonei, Unlike Its Homologues, Cratylia floribunda Lectin and Canavalia gladiata Lectin

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Juliana Montezuma Barbosa Monteiro Tínel

2014-01-01

Full Text Available Leishmaniasis is a vector-borne disease transmitted by phlebotomine sand fly. Susceptibility and refractoriness to Leishmania depend on the outcome of multiple interactions that take place within the sand fly gut. Promastigote attachment to sand fly midgut epithelium is essential to avoid being excreted together with the digested blood meal. Promastigote and gut sand fly surface glycans are important ligands in this attachment. The purpose of the present study was to evaluate the interaction of three lectins isolated from leguminous seeds (Diocleinae subtribe, D-glucose and D-mannose-binding, with glycans on Lutzomyia migonei midgut. To study this interaction the lectins were labeled with FITC and a fluorescence assay was performed. The results showed that only Dioclea violacea lectin (DVL was able to interact with midgut glycans, unlike Cratylia floribunda lectin (CFL and Canavalia gladiata lectin (CGL. Furthermore, when DVL was blocked with D-mannose the interaction was inhibited. Differences of spatial arrangement of residues and volume of carbohydrate recognition domain (CRD may be the cause of the fine specificity of DVL for glycans in the surface on Lu. migonei midgut. The findings in this study showed the presence of glycans in the midgut with glucose/mannose residues in its composition and these residues may be important in interaction between Lu. migonei midgut and Leishmania.

Lectin binding profiles of SSEA-4 enriched, pluripotent human embryonic stem cell surfaces

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Venable, Alison; Mitalipova, Maisam; Lyons, Ian; Jones, Karen; Shin, Soojung; Pierce, Michael; Stice, Steven

2005-01-01

Background Pluripotent human embryonic stem cells (hESCs) have the potential to form every cell type in the body. These cells must be appropriately characterized prior to differentiation studies or when defining characteristics of the pluripotent state. Some developmentally regulated cell surface antigens identified by monoclonal antibodies in a variety of species and stem cell types have proven to be side chains of membrane glycolipids and glycoproteins. Therefore, to examine hESC surfaces for other potential pluripotent markers, we used a panel of 14 lectins, which were chosen based on their specificity for a variety of carbohydrates and carbohydrate linkages, along with stage specific embryonic antigen-4 (SSEA-4), to determine binding quantitation by flow cytometry and binding localization in adherent colonies by immunocytochemistry. Results Enriching cells for SSEA-4 expression increased the percentage of SSEA-4 positive cells to 98–99%. Using enriched high SSEA-4-expressing hESCs, we then analyzed the binding percentages of selected lectins and found a large variation in binding percentages ranging from 4% to 99% binding. Lycopersicon (tomato)esculetum lectin (TL), Ricinus communis agglutinin (RCA), and Concanavalin A (Con A) bound to SSEA-4 positive regions of hESCs and with similar binding percentages as SSEA-4. In contrast, we found Dolichos biflorus agglutinin (DBA) and Lotus tetragonolobus lectin (LTL) did not bind to hESCs while Phaseolus vulgaris leuco-agglutinin (PHA-L), Vicia villosa agglutinin (VVA), Ulex europaeus agglutinin (UEA), Phaseolus vulgaris erythro-agglutinin (PHA-E), and Maackia amurensis agglutinin (MAA) bound partially to hESCs. These binding percentages correlated well with immunocytochemistry results. Conclusion Our results provide information about types of carbohydrates and carbohydrate linkages found on pluripotent hESC surfaces. We propose that TL, RCA and Con A may be used as markers that are associated with the pluripotent

Lectin binding profiles of SSEA-4 enriched, pluripotent human embryonic stem cell surfaces

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Shin Soojung

2005-07-01

Full Text Available Abstract Background Pluripotent human embryonic stem cells (hESCs have the potential to form every cell type in the body. These cells must be appropriately characterized prior to differentiation studies or when defining characteristics of the pluripotent state. Some developmentally regulated cell surface antigens identified by monoclonal antibodies in a variety of species and stem cell types have proven to be side chains of membrane glycolipids and glycoproteins. Therefore, to examine hESC surfaces for other potential pluripotent markers, we used a panel of 14 lectins, which were chosen based on their specificity for a variety of carbohydrates and carbohydrate linkages, along with stage specific embryonic antigen-4 (SSEA-4, to determine binding quantitation by flow cytometry and binding localization in adherent colonies by immunocytochemistry. Results Enriching cells for SSEA-4 expression increased the percentage of SSEA-4 positive cells to 98–99%. Using enriched high SSEA-4-expressing hESCs, we then analyzed the binding percentages of selected lectins and found a large variation in binding percentages ranging from 4% to 99% binding. Lycopersicon (tomatoesculetum lectin (TL, Ricinus communis agglutinin (RCA, and Concanavalin A (Con A bound to SSEA-4 positive regions of hESCs and with similar binding percentages as SSEA-4. In contrast, we found Dolichos biflorus agglutinin (DBA and Lotus tetragonolobus lectin (LTL did not bind to hESCs while Phaseolus vulgaris leuco-agglutinin (PHA-L, Vicia villosa agglutinin (VVA, Ulex europaeus agglutinin (UEA, Phaseolus vulgaris erythro-agglutinin (PHA-E, and Maackia amurensis agglutinin (MAA bound partially to hESCs. These binding percentages correlated well with immunocytochemistry results. Conclusion Our results provide information about types of carbohydrates and carbohydrate linkages found on pluripotent hESC surfaces. We propose that TL, RCA and Con A may be used as markers that are associated with the

Urease from Helicobacter pylori is inactivated by sulforaphane and other isothiocyanates

Science.gov (United States)

Fahey, Jed W.; Stephenson, Katherine K.; Wade, Kristina L.; Talalay, Paul

2013-01-01

Infections by Helicobacter pylori are very common, causing gastroduodenal inflammation including peptic ulcers, and increasing the risk of gastric neoplasia. The isothiocyanate (ITC) sulforaphane [SF; 1-isothiocyanato-4-(methylsulfinyl)butane] derived from edible crucifers such as broccoli is potently bactericidal against Helicobacter, including antibiotic-resistant strains, suggesting a possible dietary therapy. Gastric H. pylori infections express high urease activity which generates ammonia, neutralizes gastric acidity, and promotes inflammation. The finding that SF inhibits (inactivates) urease (jack bean and Helicobacter) raised the issue of whether these properties might be functionally related. The rates of inactivation of urease activity depend on enzyme and SF concentrations and show first order kinetics. Treatment with SF results in time-dependent increases in the ultraviolet absorption of partially purified Helicobacter urease in the 280–340 nm region. This provides direct spectroscopic evidence for the formation of dithiocarbamates between the ITC group of SF and cysteine thiols of urease. The potencies of inactivation of Helicobacter urease by isothiocyanates structurally related to SF were surprisingly variable. Natural isothiocyanates closely related to SF, previously shown to be bactericidal (berteroin, hirsutin, phenethyl isothiocyanate, alyssin, and erucin), did not inactivate urease activity. Furthermore, SF is bactericidal against both urease positive and negative H. pylori strains. In contrast, some isothiocyanates such as benzoyl-ITC, are very potent urease inactivators, but are not bactericidal. The bactericidal effects of SF and other ITC against Helicobacter are therefore not obligatorily linked to urease inactivation, but may reduce the inflammatory component of Helicobacter infections. PMID:23583386

The conservative behaviour of fluorescein | Smith | Water SA

African Journals Online (AJOL)

Failure to account for fluorescein absorbance changes with pH may be responsible for some of the apparent non-conservative behaviour of this easily detectable tracer compound. While it is possible to calculate an accurate absorptivity value for fluorescein at every pH, this calculation is not necessary if the sample pH is ...

Lectin histochemistry and alkaline phosphatase activity in the pia mater vessels of spontaneously hypertensive rats (SHR).

Science.gov (United States)

Szumańska, G; Gadamski, R

1992-01-01

Some lectins were used to study the localization of sugar residues on the endothelial cell surface in the pia mater blood vessels of control (WKY) and hypertensive rats (SHR). The lectins tested recognized the following residues: beta-D-galactosyl (Ricinus communis agglutinin 120, RCA-1), alpha-L-fucosyl (Ulex europaeus agglutinin, UEA-1), N-acetylglucosaminyl and sialyl (Wheat germ agglutinin, WGA), N-glycolyl-neuraminic acid (Limax flavus agglutinin, LFA), and N-acetyl-D-galactosaminyl (Helix pomatia agglutinin, HPA). Several differences were revealed in the presence of sugar receptors on the surface of endothelial cells between the control and the hypertensive rats. Our studies showed also differences in the localization of the tested glycoconjugates between pial capillaries, small, medium-size and large pial arteries. The histochemical evaluation of alkaline phosphatase revealed an increased activity of the enzyme in the pial vessels of SHRs as compared with control rats with a similar localization of the enzyme activity. Some differences in the distribution of lectin binding sites and alkaline phosphatase activity could be associated with the different functions of particular segments of the pial vascular network.

Lectins, Interconnecting Proteins with Biotechnological/Pharmacological and Therapeutic Applications

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Luana Cassandra Breitenbach Barroso Coelho

2017-01-01

Full Text Available Lectins are proteins extensively used in biomedical applications with property to recognize carbohydrates through carbohydrate-binding sites, which identify glycans attached to cell surfaces, glycoconjugates, or free sugars, detecting abnormal cells and biomarkers related to diseases. These lectin abilities promoted interesting results in experimental treatments of immunological diseases, wounds, and cancer. Lectins obtained from virus, microorganisms, algae, animals, and plants were reported as modulators and tool markers in vivo and in vitro; these molecules also play a role in the induction of mitosis and immune responses, contributing for resolution of infections and inflammations. Lectins revealed healing effect through induction of reepithelialization and cicatrization of wounds. Some lectins have been efficient agents against virus, fungi, bacteria, and helminths at low concentrations. Lectin-mediated bioadhesion has been an interesting characteristic for development of drug delivery systems. Lectin histochemistry and lectin-based biosensors are useful to detect transformed tissues and biomarkers related to disease occurrence; antitumor lectins reported are promising for cancer therapy. Here, we address lectins from distinct sources with some biological effect and biotechnological potential in the diagnosis and therapeutic of diseases, highlighting many advances in this growing field.

Permeability of blood-tear barrier to fluorescein and albumin after application of platelet-activating factor to the eye of the guinea pig

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J. L. Van Delft

1997-01-01

Full Text Available One of the inflammatory responses of the eye to local application of platelet-activating factor (PAF is oedema of the conjunctiva, caused by extravasation of plasma. Aim of the study was to investigate if fluorescein would leak from the blood into the tears together with plasma protein after application of PAF to the eye. Fluorescein was given intraperitoneally 30 min prior to application of 25 μl of 0.1% solution of PAF. Thirty min after PAF the tear film was collected by washing the surface of the eye with 25 μl of phosphate buffered saline (PBS. Fluorescein in eye washings and in plasma was measured by fluorophotometry and albumin by immunodiffusion. Both fluorescein and albumin appeared in a related fashion in tears, being absent in washings of placebo-treated control eyes. Extravasation of fluorescein can be used as a measure for plasma leakage in the conjunctiva with the advantage over the Evans Blue method that the former is a non-invasive method.

Lectin activity in mycelial extracts of Fusarium species.

Science.gov (United States)

Bhari, Ranjeeta; Kaur, Bhawanpreet; Singh, Ram S

2016-01-01

Lectins are non-immunogenic carbohydrate-recognizing proteins that bind to glycoproteins, glycolipids, or polysaccharides with high affinity and exhibit remarkable ability to agglutinate erythrocytes and other cells. In the present study, ten Fusarium species previously not explored for lectins were screened for the presence of lectin activity. Mycelial extracts of F. fujikuroi, F. beomiformii, F. begoniae, F. nisikadoi, F. anthophilum, F. incarnatum, and F. tabacinum manifested agglutination of rabbit erythrocytes. Neuraminidase treatment of rabbit erythrocytes increased lectin titers of F. nisikadoi and F. tabacinum extracts, whereas the protease treatment resulted in a significant decline in agglutination by most of the lectins. Results of hapten inhibition studies demonstrated unique carbohydrate specificity of Fusarium lectins toward O-acetyl sialic acids. Activity of the majority of Fusarium lectins exhibited binding affinity to d-ribose, l-fucose, d-glucose, l-arabinose, d-mannitol, d-galactosamine hydrochloride, d-galacturonic acid, N-acetyl-d-galactosamine, N-acetyl-neuraminic acid, 2-deoxy-d-ribose, fetuin, asialofetuin, and bovine submaxillary mucin. Melibiose and N-glycolyl neuraminic acid did not inhibit the activity of any of the Fusarium lectins. Mycelial extracts of F. begoniae, F. nisikadoi, F. anthophilum, and F. incarnatum interacted with most of the carbohydrates tested. F. fujikuroi and F. anthophilum extracts displayed strong interaction with starch. The expression of lectin activity as a function of culture age was investigated. Most species displayed lectin activity on the 7th day of cultivation, and it varied with progressing of culture age. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Lectins discriminate between pathogenic and nonpathogenic South American trypanosomes

International Nuclear Information System (INIS)

de Miranda Santos, I.K.; Pereira, M.E.

1984-01-01

Cell surface carbohydrates of Trypanosoma cruzi, Trypanosoma rangeli, and Trypanosoma conorhini were analyzed by a micro-agglutination assay employing 27 highly purified lectins and by binding assays using various 125 I-labeled lectins. The following seven lectins discriminated between the trypanosomes: 1) tomato lectin (an N-acetyl-D-glucosamine-binding protein), both in purified form and as crude tomato juice; 2) Bauhinea purpurea and Sophora japonica lectins (both N-acetyl-D-galactosamine-binding proteins), which selectively agglutinated T. cruzi; 3) Vicia villosa (an N-acetyl-D-galactosamine-binding protein) which was specific for T. rangeli; 4) peanut lectin (a D-galactose-binding protein) both in purified form and as crude saline extract; and 5) Ulex europaeus and Lotus tetragonolobus (both L-fucose-binding proteins) lectins which reacted only with T. conorhini. Binding studies with 125I-labeled lectins were performed to find whether unagglutinated cells of the three different species of trypanosomes might have receptors for these lectins, in which case absence of agglutination could be due to a peculiar arrangement of the receptors. These assays essentially confirmed the agglutination experiments

Lectins discriminate between pathogenic and nonpathogenic South American trypanosomes

Energy Technology Data Exchange (ETDEWEB)

de Miranda Santos, I.K.; Pereira, M.E.

1984-09-01

Cell surface carbohydrates of Trypanosoma cruzi, Trypanosoma rangeli, and Trypanosoma conorhini were analyzed by a micro-agglutination assay employing 27 highly purified lectins and by binding assays using various /sup 125/I-labeled lectins. The following seven lectins discriminated between the trypanosomes: 1) tomato lectin (an N-acetyl-D-glucosamine-binding protein), both in purified form and as crude tomato juice; 2) Bauhinea purpurea and Sophora japonica lectins (both N-acetyl-D-galactosamine-binding proteins), which selectively agglutinated T. cruzi; 3) Vicia villosa (an N-acetyl-D-galactosamine-binding protein) which was specific for T. rangeli; 4) peanut lectin (a D-galactose-binding protein) both in purified form and as crude saline extract; and 5) Ulex europaeus and Lotus tetragonolobus (both L-fucose-binding proteins) lectins which reacted only with T. conorhini. Binding studies with 125I-labeled lectins were performed to find whether unagglutinated cells of the three different species of trypanosomes might have receptors for these lectins, in which case absence of agglutination could be due to a peculiar arrangement of the receptors. These assays essentially confirmed the agglutination experiments.

Mechanisms involved in the differential recovery of CD4 and CD8 T-lymphocytes after local irradiation in mice

International Nuclear Information System (INIS)

De Ruysscher, D; Waer, M.; Vandeputte, M.; Van der Schueren, E.

1990-01-01

The mechanisms involved in the differential recovery of CD4 (helper/inducer phenotype) and CD8 (Cytotoxic/suppressor phenotype) T-lymphocytes after fractionated local irradiation were investigated. In mice, a better recovery of CD4 cells than of CD8 cells was found, while the reverse has been described in humans. Differences in radiosensivitity between CD4 and CD8 mouse splenocytes could not be found. No sequestration of CD8 cells in irradiated tissues could be demonstrated. Irradiation of the thymus did not influence the observed immune changes. Altered thymic production of CD4 and CD8 cells could be excluded by intrathymic injection of FITC (fluorescein isothiocyanate). Hindlimb and tail irradiation did suggest that the differential recovery of CD4 and CD8 T-lymphocytes after local irradiation is determined by extrathymic factors in man and mice, and that the observed differences in immune recovery between man and mice are due to defective thymic function in the former and normal function in the latter. (author). 12 refs.; 5 figs.; 2 tabs

Cholesterol Crystals Activate the Lectin Complement Pathway via Ficolin-2 and Mannose-Binding Lectin

DEFF Research Database (Denmark)

Pilely, Katrine; Rosbjerg, Anne; Genster, Ninette

2016-01-01

Cholesterol crystals (CC) play an essential role in the formation of atherosclerotic plaques. CC activate the classical and the alternative complement pathways, but the role of the lectin pathway is unknown. We hypothesized that the pattern recognition molecules (PRMs) from the lectin pathway bind...... CC and function as an upstream innate inflammatory signal in the pathophysiology of atherosclerosis. We investigated the binding of the PRMs mannose-binding lectin (MBL), ficolin-1, ficolin-2, and ficolin-3, the associated serine proteases, and complement activation products to CC in vitro using...... recognize CC and provides evidence for an important role for this pathway in the inflammatory response induced by CC in the pathophysiology of atherosclerosis....

Lectin cDNA and transgenic plants derived therefrom

Science.gov (United States)

Raikhel, Natasha V.

2000-10-03

Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties.

Localization of binding sites of Ulex europaeus I, Helix pomatia and Griffonia simplicifolia I-B4 lectins and analysis of their backbone structures by several glycosidases and poly-N-acetyllactosamine-specific lectins in human breast carcinomas.

Science.gov (United States)

Ito, N; Imai, S; Haga, S; Nagaike, C; Morimura, Y; Hatake, K

1996-09-01

Several studies have shown the deletion of blood group A or B antigens and the accumulation of H antigens in human breast carcinomas. Other studies have independently demonstrated that the binding sites of lectins such as Helix pomatia agglutinin (HPA) and Griffonia simplicifolia agglutinin I-B4 (GSAI-B4) are highly expressed in these cells. In order to clarify the molecular mechanisms of malignant transformation and metastasis of carcinoma cells, it is important to understand the relationship between such phenotypically distinct events. For this purpose, we examined whether the binding sites of these lectins and Ulex europaeus agglutinin I (UEA-I) are expressed concomitantly in the same carcinoma cells and analyzed their backbone structures. The expression of the binding sites of these lectins was observed independently of the blood group (ABO) of the patients and was not affected by the histological type of the carcinomas. Observation of serial sections stained with these lectins revealed that the distribution of HPA binding sites was almost identical to that of GSAI-B4 in most cases. Furthermore, in some cases, UEA-I binding patterns were similar to those of HPA and GSAI-B4 but in other cases, mosaic staining patterns with these lectins were also observed, i.e., some cell clusters were stained with both HPA and GSAI-B4 but not with UEA-I and adjacent cell clusters were stained only with UEA-I. Digestion with endo-beta-galactosidase or N-glycosidase F markedly reduced the staining intensity of these lectins. Together with the reduction of staining by these lectins, reactivity with Griffonia simplicifolia agglutinin II appeared in carcinoma cells following endo-beta-galactosidase digestion. Among the lectins specific to poly-N-acetyllactosamine, Lycopersicon esculentum agglutinin (LEA) most vividly and consistently stained the cancer cells. Next to LEA, pokeweed mitogen agglutinin was also effective in staining these cells. Carcinoma cells reactive with these

Contact and fumigant toxicity of Armoracia rusticana essential oil, allyl isothiocyanate and related compounds to Dermatophagoides farinae.

Science.gov (United States)

Yun, Yeon-Kyeong; Kim, Hyun-Kyung; Kim, Jun-Ran; Hwang, Kumnara; Ahn, Young-Joon

2012-05-01

The toxicity to adult Dermatophagoides farinae of allyl isothiocyanate identified in horseradish, Armoracia rusticana, oil and another 27 organic isothiocyanates was evaluated using contact + fumigant and vapour-phase mortality bioassays. Results were compared with those of two conventional acaricides, benzyl benzoate and dibutyl phthalate. Horseradish oil (24 h LC(50), 1.54 µg cm(-2)) and allyl isothiocyanate (2.52 µg cm(-2)) were highly toxic. Benzyl isothiocyanate (LC(50) , 0.62 µg cm(-2)) was the most toxic compound, followed by 4-chlorophenyl, 3-bromophenyl, 3,5-bis(trifluoromethyl)phenyl, cyclohexyl, 2-chlorophenyl, 4-bromophenyl and 2-bromophenyl isothiocyanates (0.93-1.41 µg cm(-2)). All were more effective than either benzyl benzoate (LC(50) , 4.58 µg cm(-2)) or dibutyl phthalate (24.49 µg cm(-2)). The structure-activity relationship indicates that types of functional group and chemical structure appear to play a role in determining the isothiocyanate toxicities to adult D. farinae. In the vapour-phase mortality bioassay, these isothiocyanates were consistently more toxic in closed versus open containers, indicating that their mode of delivery was, in part, a result of vapour action. In the light of global efforts to reduce the level of highly toxic synthetic acaricides in indoor environments, the horseradish oil-derived compounds and the isothiocyanates described herein merit further study as potential acaricides for the control of house dust mite populations as fumigants with contact action. Copyright © 2011 Society of Chemical Industry.

The effect of colloidal silica nanoparticles encapsulated fluorescein dye using micelle entrapment method

Science.gov (United States)

Ahmad, Atiqah; Zakaria, Nor Dyana; Lockman, Zainovia; Razak, Khairunisak Abdul

2018-05-01

The advancement of nanoparticle-based approaches such as quantum dots (QDs), metallic (Au and Ag) NPs, silica NPs and other types of nanomaterial have led to a large variety of biomolecular imaging and labelling reagents with controlled size and shaped to overcome the limitation of conventional organic dye. In this study, the yellowish green color of fluorescein dye was encapsulated into colloidal silica nanoparticles by using micelle entrapment approach. Two different size of silica nanoparticles encapsulated fluorescein dye (27.7 ± 5.6 and 46.73 ± 4.3 nm) with spherical and monodispered of nanoparticles were synthesised by varying the volume of co-solvent during the synthesis process. The particles size, particles morphology, absorption spectrum and the photostability of fluorescein dye was measured by using dynamic light scaterring (DLS), Transmission Electron Microscope (TEM) and UV-Vis spectrometer. Furthermore, the effect of photostability of of silica nanoparticles encapsulated fluorescein dye was measured under radiation of 200 W of Halogen lamp for 60 minutes. The silica nanoparticles encapsulated fluorescein dye was more stable compared to bare fluorescein dye after the exposure. In conclusion, the photostability of silica nanoparticles encapsulated fluorescein dye was improved compared to bare fluorescein dye, thus silica nanoparticles encapsulation successfully provides protection from the photobleaching and photodegradation of fluorescein dye.

Maskless localized patterning of biomolecules on carbon nanotube microarray functionalized by ultrafine atmospheric pressure plasma jet using biotin-avidin system

Science.gov (United States)

Abuzairi, Tomy; Okada, Mitsuru; Purnamaningsih, Retno Wigajatri; Poespawati, Nji Raden; Iwata, Futoshi; Nagatsu, Masaaki

2016-07-01

Ultrafine plasma jet is a promising technology with great potential for nano- or micro-scale surface modification. In this letter, we demonstrated the use of ultrafine atmospheric pressure plasma jet (APPJ) for patterning bio-immobilization on vertically aligned carbon nanotube (CNT) microarray platform without a physical mask. The biotin-avidin system was utilized to demonstrate localized biomolecule patterning on the biosensor devices. Using ±7.5 kV square-wave pulses, the optimum condition of plasma jet with He/NH3 gas mixture and 2.5 s treatment period has been obtained to functionalize CNTs. The functionalized CNTs were covalently linked to biotin, bovine serum albumin (BSA), and avidin-(fluorescein isothiocyanate) FITC, sequentially. BSA was necessary as a blocking agent to protect the untreated CNTs from avidin adsorption. The localized patterning results have been evaluated from avidin-FITC fluorescence signals analyzed using a fluorescence microscope. The patterning of biomolecules on the CNT microarray platform using ultrafine APPJ provides a means for potential application of microarray biosensors based on CNTs.

Optimized Formation of Benzyl Isothiocyanate by Endogenous ...

African Journals Online (AJOL)

Purpose: To use endogenous myrosinase in Carica papaya seed to convert benzyl glucosinolate (BG) to benzyl isothiocyanate (BITC) and then extract it for further studies. Methods: Process variables including seed powder particle size, sample-to-solvent ratio, pH of buffer solution, enzymolysis temperature, enzymolysis ...

Visualisation of lectin binding sites on the surface of human platelets using lectins adsorbed to gold granules.

Science.gov (United States)

Nurden, A T; Horisberger, M; Savariau, E; Caen, J P

1980-10-15

Washed human platelets have been incubated with the lectins WGA, ConA and RCA1, adsorbed to different-sized gold particles. Plasma membrane receptors for each lectin were then located by scanning and transmission electron microscopy.

Studies on lectins. XXXII. Application of affinity electrophoresis to the study of the interaction of lectins and their derivatives with sugars.

Science.gov (United States)

Horejsí, V; Tichá, M; Kocourek, J

1977-09-29

Affinity electrophoresis was used to study the sugar binding heterogeneity of lectins or their derivatives. Commercial and demetallized preparations of concanavalin A could be resolved by affinity electrophoresis into three components with different affinity to immobilized sugar. Similarly the Vicia cracca lectin obtained by affinity chromatography behaved on affinity gels as a mixture of active and inactive molecular species. Affinity electrophoresis has shown that the nonhemagglutinating acetylated lentil lectin and photo-oxidized or sulfenylated pea lectin retain their sugar binding properties; dissociation constants of saccharide complexes of these derivatives are similar to those of native lectins. The presence of specific immobilized sugar in the affinity gel improved the resolution of isolectins from Dolichos biflorus and Ricinus communis seeds.

Common skate (Raja kenojei) secretes pentraxin into the cutaneous secretion: The first skin mucus lectin in cartilaginous fish.

Science.gov (United States)

Tsutsui, Shigeyuki; Yamaguchi, Motoki; Hirasawa, Ai; Nakamura, Osamu; Watanabe, Tasuku

2009-08-01

A lactose-specific lectin with a molecular mass of about 25 kDa was purified from the skin mucus of a cartilaginous fish-the common skate (Raja kenojei). The complementary DNA sequence of the lectin was 1540 bp long and contained a reading frame encoding 226 amino acids, which showed approximately 38% identity to pentraxins of mammals and teleosts. Gene expression was observed in the skin, gill, stomach and intestine in the healthy skate. We also identified an isotype gene from the liver whose deduced amino-acid sequence shared 69.0% identity with the skin type gene. The antiserum detected protein in the skin, where the lectin is localized in the epidermal cells, and in the blood plasma. The lectin genes are multicopied in the common skate genome. Although pentraxins are acute phase proteins, mRNAs of both the isotypes were not upregulated after the in vivo challenge with formalin-killed Escherichia coli, which suggests that they are constantly present in the skin mucus and blood plasma to protect against pathogenic invasion. This lectin is the fifth type of lectin found in the cutaneous secretions of fish, demonstrating that skin mucus lectins have evolved with marked molecular diversity in fish.

Case Report of Bullous Pemphigoid following Fundus Fluorescein Angiography

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Goktug Demirci

2010-05-01

Full Text Available Purpose: To report a first case of bullous pemphigoid (BP following intravenous fluorescein for fundus angiography. Clinical Features: A 70-year-old male patient was admitted to the intensive care unit with BP and sepsis. He reported a history of fundus fluorescein angiography with a pre-diagnosis of senile macular degeneration 2 months prior to presentation. At that time, fluorescein extravasated at the antecubital region. Following the procedure, pruritus and erythema began at the wrists bilaterally, and quickly spread to the entire body. The patient also reported a history of allergy to human albumin solution (Plamasteril®; Abbott 15 years before, during bypass surgery. On dermatologic examination, erythematous patches were present on the scalp, chest and anogenital region. Vesicles and bullous lesions were present on upper and lower extremities. On day 2 of hospitalization, tense bullae appeared on the upper and lower extremities. The patient was treated with oral methylprednisolone 48 mg (Prednol®; Mustafa Nevzat, topical clobetasol dipropionate 0.05% cream (Dermovate®; Glaxo SmithKline, and topical 4% urea lotion (Excipial Lipo®; Orva for presumptive bullous pemphigoid. Skin punch biopsy provided tissue for histopathology, direct immunofluorescence examination, and salt extraction, which were all consistent with BP. After 1 month, the patient was transferred to the intensive care unit with sepsis secondary to urinary tract infection; he died 2 weeks later from sepsis and cardiac failure. Conclusions: To our knowledge, this is the first reported case of BP following fundus fluorescein angiography in a patient with known human albumin solution allergy. Consideration should be made to avoid fluorescein angiography, change administration route, or premedicate with antihistamines in patients with known human albumin solution allergy. The association between fundus fluorescein angiography and BP should be further investigated.

Antimicrobial activities of isothiocyanates against Campylobacter jejuni isolates

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Virginie eDufour

2012-04-01

Full Text Available Food-borne human infection with Campylobacter jejuni is a medical concern in both industrialized and developing countries. Efficient eradication of C. jejuni reservoirs within live animals and processed foods is limited by the development of antimicrobial resistances and by practical problems related to the use of conventional antibiotics in food processes.We have investigated the bacteriostatic and bactericidal activities of two phytochemicals, allyl-isothiocyanate (AITC and benzyl-isothiocyanate (BITC, against 24 C. jejuni isolates from chicken feces, human infections and contaminated foods, as well as two reference strains NCTC11168 and 81-176.Both AITC and BITC displayed a potent antibacterial activity against C. jejuni. BITC showed a higher overall antibacterial effect (MIC of 2.5 to 5 g mL-1 compared to AITC (MIC of 50 to 200 g mL-1. Interestingly, the 24 C. jejuni isolates could be classified in 3 groups according to their sensitivity levels to both compounds, suggesting that AITC and BITC shared identical activity mechanisms and consequently faced similar resistance processes in bacterial cells.The sensitivity levels of C. jejuni strains against isothiocyanates were neither correlated with the presence of a GGT (-Glutamyl Transpeptidase encoding gene in the genome nor with the origin of the biological sample. However the ggt mutant of C. jejuni 81-176 displayed a decreased survival rate compared to WT when exposed to ITC.

Use of lectin-functionalized particles for oral immunotherapy

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Diesner, Susanne C; Wang, Xue-Yan; Jensen-Jarolim, Erika; Untersmayr, Eva; Gabor, Franz

2013-01-01

Immunotherapy, in recent times, has found its application in a variety of immunologically mediated diseases. Oral immunotherapy may not only increase patient compliance but may, in particular, also induce both systemic as well as mucosal immune responses, due to mucosal application of active agents. To improve the bioavailability and to trigger strong immunological responses, recent research projects focused on the encapsulation of drugs and antigens into polymer particles. These particles protect the loaded antigen from the harsh conditions in the GI tract. Furthermore, modification of the surface of particles by the use of lectins, such as Aleuria aurantia lectin, wheatgerm agglutinin or Ulex europaeus-I, enhances the binding to epithelial cells, in particular to membranous cells, of the mucosa-associated lymphoid tissue. Membranous cell-specific targeting leads to an improved transepithelial transport of the particle carriers. Thus, enhanced uptake and presentation of the encapsulated antigen by antigen-presenting cells favor strong systemic, but also local, mucosal immune responses. PMID:22834202

Fluorescein Derivatives in Intravital Fluorescence Imaging

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Michael S. Roberts

2013-08-01

Full Text Available Intravital fluorescence microscopy enables the direct imaging of fluorophores in vivo and advanced techniques such as fluorescence lifetime imaging (FLIM enable the simultaneous detection of multiple fluorophores. Consequently, it is now possible to record distribution and metabolism of a chemical in vivo and to optimise the delivery of fluorophores in vivo. Recent clinical applications with fluorescein and other intravital fluorescent stains have occurred in neurosurgery, dermatology [including photodynamic therapy (PDT] and endomicroscopy. Potential uses have been identified in periodontal disease, skin graft and cancer surgery. Animal studies have demonstrated that diseased tissue can be specifically stained with fluorophore conjugates. This review focuses on the fluorescein derived fluorophores in common clinical use and provides examples of novel applications from studies in tissue samples.

Electrochemiluminescence of fluorescein in alkaline solution at a polycrystalline gold electrode

International Nuclear Information System (INIS)

Shi Mingjuan; Cui Hua

2007-01-01

The electrochemiluminescence (ECL) behavior of fluorescein at a polycrystalline gold electrode was studied under conventional cyclic voltammetric conditions. Five ECL peaks were observed at 0.94 (ECL-1), 1.51 (ECL-2), 1.34 (ECL-3), -0.06 (ECL-4), -0.73 to -1.11 V (ECL-5, a broad weak wave) (vs. SCE), respectively, on the curve of ECL intensity versus potential. These ECL peaks were found to depend on the pH of the solution, supporting electrolyte, potential scan ranges and directions. The emitter of ECL peaks was identified as fluorescein or eosin Y produced on the electrode by analyzing the ECL spectra and fluorescence spectra. The mechanisms for ECL peaks have been proposed due to the reactions of fluorescein and the electro-oxidation product of fluorescein with various oxygen-containing species in the solution or electrogenerated at different applied potentials such as O 2 , O 2 .- , HO 2 - , and BrO - . Singlet molecular oxygen was generated during the reactions and transferred its energy to the ECL emitter such as fluorescein or eosin Y, emitting light

Lectindb: a plant lectin database.

Science.gov (United States)

Chandra, Nagasuma R; Kumar, Nirmal; Jeyakani, Justin; Singh, Desh Deepak; Gowda, Sharan B; Prathima, M N

2006-10-01

Lectins, a class of carbohydrate-binding proteins, are now widely recognized to play a range of crucial roles in many cell-cell recognition events triggering several important cellular processes. They encompass different members that are diverse in their sequences, structures, binding site architectures, quaternary structures, carbohydrate affinities, and specificities as well as their larger biological roles and potential applications. It is not surprising, therefore, that the vast amount of experimental data on lectins available in the literature is so diverse, that it becomes difficult and time consuming, if not impossible to comprehend the advances in various areas and obtain the maximum benefit. To achieve an effective use of all the data toward understanding the function and their possible applications, an organization of these seemingly independent data into a common framework is essential. An integrated knowledge base ( Lectindb, http://nscdb.bic.physics.iisc.ernet.in ) together with appropriate analytical tools has therefore been developed initially for plant lectins by collating and integrating diverse data. The database has been implemented using MySQL on a Linux platform and web-enabled using PERL-CGI and Java tools. Data for each lectin pertain to taxonomic, biochemical, domain architecture, molecular sequence, and structural details as well as carbohydrate and hence blood group specificities. Extensive links have also been provided for relevant bioinformatics resources and analytical tools. Availability of diverse data integrated into a common framework is expected to be of high value not only for basic studies in lectin biology but also for basic studies in pursuing several applications in biotechnology, immunology, and clinical practice, using these molecules.

Lectin receptors in the human cornea.

Science.gov (United States)

Holmes, M J; Mannis, M J; Lund, J; Jacobs, L

Five different biotin labeled lectins, Concanavalin-A (Con A), wheat germ agglutinin (WGA), Ricinus communis agglutinin I (RCA1), Ulex europaeus agglutinin (UEA1), and soybean agglutinin (SBA) were used to study lectin receptors on formalin-fixed paraffin embedded human corneas. Con A stained the cytoplasm, cell, and nuclear membranes of the epithelial cells and stained the stroma diffusely. WGA stained the superficial epithelial cells, the epithelial cell membranes, and the keratocytes of the stroma. SBA did not react with any of the corneal layers. RCA1 heavily stained the keratocytes but did not stain the epithelium. UEA1 lightly stained the epithelial cell cytoplasm and interstitial stroma. All staining reactions could be abolished by omission of the lectin or by the use of the appropriate inhibitory sugar. The lectin binding patterns reported here provide a means for further investigation of carbohydrate structures in the human cornea in both normal and disease states.

Activities of lectins and their immobilized derivatives in detergent solutions. Implications on the use of lectin affinity chromatography for the purification of membrane glycoproteins.

Science.gov (United States)

Lotan, R; Beattie, G; Hubbell, W; Nicolson, G L

1977-05-03

The effects of several commonly used detergents on the saccharide-binding activities of lectins were investigated using lectin-mediated agglutination of formalin-fixed erythrocytes and affinity chromatography of glycoproteins on columns of lectins immobilized on polyacrylic hydrazide-Sepharose. In the hemagglutination assays, Ricinus communis I (RCA1) and II (RCAII), concanavalin A (Con A), and the agglutinins from peanut (PNA), soybean (SBA), wheat germ (WGA), and Limulus polyphemus (LPA) were tested with several concentrations of switterionic, cationic, anionic, and nonionic detergents. It was found that increasing detergent concentrations eventually affected hemagglutination titers in both test and control samples, and the highest detergent concentrations not affecting lectin hemagglutinating activities were determined. The effects of detergents on specific binding of [3H]fetuin and asialo[3H]fetuin to and elution from columns of immobilized lectins were less severe when compared with lectins in solution, suggesting that the lectins are stabilized by covalent attachment to agarose beads. Nonionic detergents did not affect the binding efficiency of the immobilized lectins tested at concentrations used for membrane solubilization while cationic and zwitterionic detergents caused significant inhibition of Con A- and SBA-Sepharose activities. In sodium deoxycholate (greater than 1%) only RCAI-Sepharose retained its activity, whereas the activities of the other lectins were reduced dramatically. Low concentrations of sodium dodecyl sulfate (0.05%) inhibited only the activity of immobilized SBA, but at higher concentration (0.1%) and prolonged periods of incubation (16 h, 23 degrees C) most of the lectins were inactivated. These data are compared with previous reports on the use of detergents in lectin affinity chromatography, and the conditions for the optimal use of detergents are detailed.

In vitro assessment of antiproliferative action selectivity of dietary isothiocyanates for tumor versus normal human cells

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Konić-Ristić Aleksandra

2016-01-01

Full Text Available Background/Aim. Numerous epidemiological studies have shown beneficial effects of cruciferous vegetables consumption in cancer chemoprevention. Biologically active compounds of different Brassicaceae species with antitumor potential are isothiocyanates, present in the form of their precursors - glucosinolates. The aim of this study was to determine the selectivity of antiproliferative action of dietary isothiocyanates for malignant versus normal cells. Methods. Antiproliferative activity of three isothiocyanates abundant in human diet: sulforaphane, benzyl isothiocyanate (BITC and phenylethyl isothiocyanate, on human cervix carcinoma cell line - HeLa, melanoma cell line - Fem-x, and colon cancer cell line - LS 174, and on peripheral blood mononuclear cells (PBMC, with or without mitogen, were determined by MTT colorimetric assay 72 h after their continuous action. Results. All investigated isothiocyanates inhibited the proliferation of HeLa, Fem-x and LS 174 cells. On all cell lines treated, BITC was the most potent inhibitor of cell proliferation with half-maximum inhibitory concentration (IC50 values of 5.04 mmoL m-3 on HeLa cells, 2.76 mmol m-3 on Fem-x, and 14.30 mmol m-3 on LS 174 cells. Antiproliferative effects on human PBMC were with higher IC50 than on malignant cells. Indexes of selectivity, calculated as a ratio between IC50 values obtained on PBMC and malignant cells, were between 1.12 and 16.57, with the highest values obtained for the action of BITC on melanoma Fem-x cells. Conclusion. Based on its antiproliferative effects on malignant cells, as well as the selectivity of the action to malignant vs normal cells, benzyl isothiocyanate can be considered as a promising candidate in cancer chemoprevention. In general, the safety of investigated compounds, in addition to their antitumor potential, should be considered as an important criterion in cancer chemoprevention. Screening of selectivity is a plausible approach to the evaluation

Structure predictions of two Bauhinia variegata lectins reveal patterns of C-terminal properties in single chain legume lectins.

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Moreira, Gustavo M S G; Conceição, Fabricio R; McBride, Alan J A; Pinto, Luciano da S

2013-01-01

Bauhinia variegata lectins (BVL-I and BVL-II) are single chain lectins isolated from the plant Bauhinia variegata. Single chain lectins undergo post-translational processing on its N-terminal and C-terminal regions, which determines their physiological targeting, carbohydrate binding activity and pattern of quaternary association. These two lectins are isoforms, BVL-I being highly glycosylated, and thus far, it has not been possible to determine their structures. The present study used prediction and validation algorithms to elucidate the likely structures of BVL-I and -II. The program Bhageerath-H was chosen from among three different structure prediction programs due to its better overall reliability. In order to predict the C-terminal region cleavage sites, other lectins known to have this modification were analysed and three rules were created: (1) the first amino acid of the excised peptide is small or hydrophobic; (2) the cleavage occurs after an acid, polar, or hydrophobic residue, but not after a basic one; and (3) the cleavage spot is located 5-8 residues after a conserved Leu amino acid. These rules predicted that BVL-I and -II would have fifteen C-terminal residues cleaved, and this was confirmed experimentally by Edman degradation sequencing of BVL-I. Furthermore, the C-terminal analyses predicted that only BVL-II underwent α-helical folding in this region, similar to that seen in SBA and DBL. Conversely, BVL-I and -II contained four conserved regions of a GS-I association, providing evidence of a previously undescribed X4+unusual oligomerisation between the truncated BVL-I and the intact BVL-II. This is the first report on the structural analysis of lectins from Bauhinia spp. and therefore is important for the characterisation C-terminal cleavage and patterns of quaternary association of single chain lectins.

Probing the cons and pros of lectin-induced immunomodulation: case studies for the mistletoe lectin and galectin-1.

Science.gov (United States)

Gabius, H J

2001-07-01

When imagining to monitor animal cells through a microscope with resolution at the molecular level, a salient attribute of their surfaces will be the abundance of glycan chains. They present galactosides at their termini widely extending like tentacles into the extracellular space. Their spatial accessibility and their potential for structural variability endow especially these glycan parts with capacity to act as docking points for molecular sensors (sugar receptors such as lectins). Binding and ligand clustering account for transmission of post-binding signals into the cell interior. The range of triggered activities has turned plant lectins into popular tools in cell biology and immunology. Potential for clinical application has been investigated rigorously only in recent years. As documented in vitro and in vivo for the galactoside-specific mistletoe lectin, its apparent immunomodulatory capacity reflected in upregulation of production of proinflammatory cytokines will not necessarily be clinically favorable but a double-edged sword. In fact, lectin application has been shown to stimulate tumor growth in cell lines, histocultures of human tumors and in two animal models using chemical carcinogenesis or tumor transplantation. When testing immunological effects of the endogenous lectin galectin-1, protection against disorders mediated by activated T cells came up for consideration. Elimination of these cells via CD7-dependent induction of apoptosis, and a shift to the Th2 response by the galectin, are factors to ameliorate disease states. This result encourages further efforts with other galectins. Functional redundancy, synergism, diversity or antagonism among galectins are being explored to understand the actual role of this class of endogenous lectins in inflammation. Regardless of the results of further preclinical testing for galectin-1, these two case studies break new ground in our understanding how glycans as ligands for lectins convey reactivity to

Glycoprofiling of Early Gastric Cancer Using Lectin Microarray Technology.

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Li, Taijie; Mo, Cuiju; Qin, Xue; Li, Shan; Liu, Yinkun; Liu, Zhiming

2018-01-01

Recently, studies have reported that protein glycosylation plays an important role in the occurrence and development of cancer. Gastric cancer is a common cancer with high morbidity and mortality owing to most gastric cancers are discovered only at an advanced stage. Here, we aim to discover novel specific serum glycanbased biomarkers for gastric cancer. A lectin microarray with 50 kinds of tumor-associated lectin was used to detect the glycan profiles of serum samples between early gastric cancer and healthy controls. Then lectin blot was performed to validate the differences. The result of the lectin microarray showed that the signal intensities of 13 lectins showed significant differences between the healthy controls and early gastric cancer. Compared to the healthy, the normalized fluorescent intensities of the lectins PWA, LEL, and STL were significantly increased, and it implied that their specifically recognized GlcNAc showed an especially elevated expression in early gastric cancer. Moreover, the binding affinity of the lectins EEL, RCA-II, RCA-I, VAL, DSA, PHA-L, UEA, and CAL were higher in the early gastric cancer than in healthy controls. These glycan structures containing GalNAc, terminal Galβ 1-4 GlcNAc, Tri/tetraantennary N-glycan, β-1, 6GlcNAc branching structure, α-linked fucose residues, and Tn antigen were elevated in gastric cancer. While the two lectins CFL GNL reduced their binding ability. In addition, their specifically recognized N-acetyl-D-galactosamine structure and (α-1,3) mannose residues were decreased in early gastric cancer. Furthermore, lectin blot results of LEL, STL, PHA-L, RCA-I were consistent with the results of the lectin microarray. The findings of our study clarify the specific alterations for glycosylation during the pathogenesis of gastric cancer. The specific high expression of GlcNAc structure may act as a potential early diagnostic marker for gastric cancer.

Fluorescein isothiocyanate labeled, magnetic nanoparticles conjugated D-penicillamine-anti-metadherin and in vitro evaluation on breast cancer cells; Avaliacao do isotiocianato de fluoresceina marcado, das nanoparticulas magneticas conjugadas da D-penicilamina antimetaderina e in vitro nas celulas do cancer de mama

Energy Technology Data Exchange (ETDEWEB)

Akca, Ozlet; Unak, Perihan; Medine, E. Ylker [Ege University (Turkey). Institute of Nuclear Sciences. Department of Nuclear Applications; Sakarya, Serhan [Adnan Menderes University (Turkey). ADUBILTEM Science and Technology Research and Development Center; Ozdemir, Caglar; Timur, Suna [Ege University (Turkey). Science Faculty. Department of Nuclear Applications

2011-07-01

Silane modified magnetic nanoparticles were prepared after capped with silica generated from the hydrolyzation of tetraethyl orthosilicate (TEOS). Amino silane (SG-Si900) was added to this solution for surface modification of silica coated magnetic particles. Finally, D-penicillamine (D-PA)-antimetadherin (anti-MTDH) was covalently linked to the amine group using glutaraldehyde as cross-linker. Magnetic nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and atomic force microscopy (AFM). AFM results showed that particles are nearly monodisperse, and the average size of particles was 40 to 50 nm. An amino acid derivative D-PA was conjugated anti-MTDH, which results the increase of uptaking potential of a conjugated agent, labelled fluorescein isothiocyanate (FITC) and then conjugated to the magnetic nanoparticles. In vitro evaluation of the conjugated D-PA-anti-MTDH-FITC to magnetic nanoparticle was studied on MCF-7 breast cancer cell lines. Fluorescence microscopy images of cells after incubation of the sample were obtained to monitor the interaction of the sample with the cancerous cells. Incorporation on cells of FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH was found higher than FITC labeled D-PA-anti-MTDH. The results show that magnetic properties and application of magnetic field increased incorporation rates. The obtained D-PA-anti-MTDH-magnetic nanoparticles-FITC complex has been used for in vitro imaging of breast cancer cells. FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH may be useful as a new class of scintigraphic agents. Results of this study are sufficiently encouraging to bring about further evaluation of this and related compounds for ultraviolet magnetic resonance (UV-MR) dual imaging. (author)

Mushroom Lectins: Specificity, Structure and Bioactivity Relevant to Human Disease

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Mohamed Ali Abol Hassan

2015-04-01

Full Text Available Lectins are non-immunoglobulin proteins that bind diverse sugar structures with a high degree of selectivity. Lectins play crucial role in various biological processes such as cellular signaling, scavenging of glycoproteins from the circulatory system, cell–cell interactions in the immune system, differentiation and protein targeting to cellular compartments, as well as in host defence mechanisms, inflammation, and cancer. Among all the sources of lectins, plants have been most extensively studied. However, more recently fungal lectins have attracted considerable attention due to their antitumor, antiproliferative and immunomodulatory activities. Given that only 10% of mushroom species are known and have been taxonomically classified, mushrooms represent an enormous unexplored source of potentially useful and novel lectins. In this review we provide an up-to-date summary on the biochemical, molecular and structural properties of mushroom lectins, as well as their versatile applications specifically focusing on mushroom lectin bioactivity.

Microbial F-type lectin domains with affinity for blood group antigens.

Science.gov (United States)

Mahajan, Sonal; Khairnar, Aasawari; Bishnoi, Ritika; Ramya, T N C

2017-09-23

F-type lectins are fucose binding lectins with characteristic fucose binding and calcium binding motifs. Although they occur with a selective distribution in viruses, prokaryotes and eukaryotes, most biochemical studies have focused on vertebrate F-type lectins. Recently, using sensitive bioinformatics search techniques on the non-redundant database, we had identified many microbial F-type lectin domains with diverse domain organizations. We report here the biochemical characterization of F-type lectin domains from Cyanobium sp. PCC 7001, Myxococcus hansupus and Leucothrix mucor. We demonstrate that while all these three microbial F-type lectin domains bind to the blood group H antigen epitope on fucosylated glycans, there are fine differences in their glycan binding specificity. Cyanobium sp. PCC 7001 F-type lectin domain binds exclusively to extended H type-2 motif, Myxococcus hansupus F-type lectin domain binds to B, H type-1 and Lewis b motifs, and Leucothrix mucor F-type lectin domain binds to a wide range of fucosylated glycans, including A, B, H and Lewis antigens. We believe that these microbial lectins will be useful additions to the glycobiologist's toolbox for labeling, isolating and visualizing glycans. Copyright © 2017 Elsevier Inc. All rights reserved.

77 FR 23269 - Determination That FUNDUSCEIN-25 (fluorescein sodium injection), 25%, and AK-FLUOR (fluorescein...

Science.gov (United States)

2012-04-18

... marketing for reasons other than safety or effectiveness. ANDAs that refer to FUNDUSCEIN-25 (fluorescein...), 25%, Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug... withdrawn from sale for reasons of safety or effectiveness. This determination will allow FDA to approve...

[Quenched fluorescein: a reference dye for instrument response function of TCSPC].

Science.gov (United States)

Pan, Hai-feng; Ding, Jing-xin; Liang, Rong-rong; Tao, Zhan-dong; Liu, Meng-wei; Zhang, San-jun; Xu, Jian-hua

2014-08-01

Measuring the instrument response function (IRF) and fitting by reconvolution algorithms are routines to improve time resolution in fluorescence lifetime measurements. Iodide ions were successfully used to quench the fluorescence of fluorescein in this study. By systematically adding saturated NaI water solution in basic fluorescein solution, the lifetimes of fluorescein were reduced from 4 ns to 24 ps. The quenched lifetime of fluorescein obtained from the analysis of Time-Correlated Single Photon Counting (TCSPC) measurement agrees well with that from femtosecond frequency up-conversion measurement. In time resolved excitation spectra measurements, the IRF should be measured at various detection wavelengths providing scattring materials are used. This study could not only reduce the complexity of IRF measurement, but also avoid the existing color effect in system. This study should have wide applications in time resolved fluorescence spectroscopy and fluorescence lifetime imaging.

Red-free light for measurement of intraocular pressure using Goldmann applanation tonometer without fluorescein.

Science.gov (United States)

Ghoneim, Ehab M

2014-01-01

To evaluate the use of red-free light for the measurement of intraocular pressure (IOP) using a Goldmann applanation tonometer without fluorescein. This cross-sectional study was carried out on 500 eyes in 250 patients attending the Ophthalmology Outpatient Clinic at Suez Canal University Hospital. The IOP was measured using a Goldmann applanation tonometer mounted on a Haag-Streit slit-lamp. The measurements were performed first using red-free light without fluorescein. Then the measurements were repeated with cobalt blue light and topical fluorescein on the same eyes. The mean IOP was 15.23 ± 3.3 (SD) mm Hg using the red-free light without fluorescein, whereas it was 15.78 ± 3.7 (SD) mm Hg when measured using cobalt blue light after the application of fluorescein to the conjunctival sac. This difference was not statistically significant. Measurement of IOP with a Goldmann applanationtonometer with red-free light and without the use of fluorescein is simple, saves time, and gives an accurate IOP measurement relative to the traditional measurement technique with cobalt blue light and topical fluorescein.

Live Staining and Isolation of Specific Hormone-Producing Cells from Rat Anterior Pituitary by Cytochemistry with Lectins and Cholera Toxin B Subunit

International Nuclear Information System (INIS)

Kikuchi, Motoshi; Kusumoto, Kenji; Fujiwara, Ken; Takahashi, Kozue; Tando, Yukiko; Yashiro, Takashi

2011-01-01

Anterior pituitary glands contain five types of hormone-producing cells. Distinguishing and isolating specific types of living cells are essential for studying their function. Although many such attempts have been made, the results have been disappointing. In the present study, we labeled specific types of living hormone-producing cells by using potential differences in sugar chains on the cell surfaces. Cytochemical analysis with lectins and cholera toxin B subunit revealed that PNA, S-WGA, and cholera toxin B subunit recognized sugar chains specific to prolactin cells, ACTH cells, and GH cells, respectively, and that UEA-I recognized most of prolactin cells and GH cells. Next, fluorescence-activated cell sorting was used to isolate GH cells labeled by fluoresceinated cholera toxin B. The purity of the GH cell fraction estimated by immunocytochemistry and quantitative real-time PCR for cell type-specific genes was more than 98%, which was higher than that reported in earlier studies, including those using transgenic animals. We conclude that cytochemistry with lectins and cholera toxin B subunit is a straightforward, acceptable method of isolating specific types of anterior pituitary cells and that the cells isolated by this method can serve as useful materials in the study of anterior pituitary cells

Purification and characterization of liver lectins from a lizard, Sceloporus spinosus.

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Fenton, N Bertha; Arreguín, L Barbarin; Méndez, C Fausto; Arreguín, E Roberto

2004-05-01

This study discusses the purification of soluble beta-galactose lectins obtained from the lizard liver of Sceloporus spinosus. The first lectin named lizard hepatic lectin-1 (LHL-1) presented a molecular weight of 31,750, with an isoelectric point of 4.25. The highest specific hemagglutinating activity was achieved using human blood type A1: N-acetylgalactosamine (GalNAc)-galactose (Gal)-fucose (Fuc). Carbohydrate inhibition assays indicated a higher lectin specificity for GalNAc. For LHL-2 the molecular weight obtained was 23,850 with an isoelectric point of 3.25. The highest carbohydrate specificity was observed for Gal. These lizard hepatic lectins are similar to the mammal hepatic lectins previously reported. However, it is different from the alligator hepatic lectin (AHL). The homology analyses of LHL-1 resulted in 100% identity with the Steroidogenic acute regulatory protein (StAR), while LHL-2 was similar to adenylate kinase (75% identity). We suggest that these liver lectins are related to the inherent functions of liver previously reported.

A survey of domestic species of Basidiomycetes fungi for the presence of lectins inn their carpophores

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Grażyna Końska

2014-01-01

Full Text Available Preliminary investigations were conducted to determine the presence of active lectins in carpophores of fungi from the class Basidiomycetes, collected from natural localities in southern and south-eastern Poland. The degree of agglutination activity (expressed as the titre of agglutination of aqueous extracts was determined at room temperature (18-20°C and at +4°C in respect to human and animal erythrocytes suspended in physiological saline, part of which were additionally treated with proteolytic enzymes. From among the 104 tested species, extracts from 41 of them showed agglutination activity, among which 18 were high. In six cases, specific activity against human ABH group antigens was found. Extracts from 5 species agglutinated only animal erythrocytes, with pigeon erythrocytes being exceptionally sensitive to the lectins. Extracts from two species had distinctly higher agglutination activity at 4°C, which suggests that lectins of the "cold" agglutinin type are present in these species. Analysis of extracts from caps and stems showed that caps had a higher lectin content.

Lectin interactions with alpha-galactosylated xenoantigens

DEFF Research Database (Denmark)

Kirkeby, Svend; Moe, Dennis

2002-01-01

alpha-Galactosylated xenoantigens (Galalpha1-3Galbeta1-4GlcNAcbeta1 and Galalpha1-3Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc) are often detected with the alpha-Gal specific lectin Griffonia simplicifolia 1 isolectin B4 (GS1 B4). However, this lectin exhibits a broad and variable specificity for carboh...

Crystal structure of chlorido(η2-phenyl isothiocyanate-κ2C,S-mer-tris(trimethylphosphane-κPiridium(I

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Joseph S. Merola

2014-11-01

Full Text Available The molecule of the title compound, [IrCl(C7H5NS(C3H9P3], is a distorted octahedral iridium complex with three PMe3 ligands arranged in a meridional geometry, a chloride ion cis to all three PMe3 groups and the phenyl isothiocyanate ligand bonded in an η2-fashion through the C and S atoms. The C atom is trans to the chloride ion and the S atom is responsible for a significant deviation from an ideal octahedral geometry. The geometric parameters for the metal-complexing phenyl isothiocyanate group are compared with other metal-complexed phenyl isothiocyanates, as well as with examples of uncomplexed aryl isothiocyanates.

Glucosinolate-derived isothiocyanates impact mitochondrial function in fungal cells and elicit an oxidative stress response necessary for growth recovery

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Benoit eCalmes

2015-06-01

Full Text Available Glucosinolates are brassicaceous secondary metabolites that have long been considered as chemical shields against pathogen invasion. Isothiocyanates, are glucosinolate-breakdown products that have negative effects on the growth of various fungal species. We explored the mechanism by which isothiocyanates could cause fungal cell death using Alternaria brassicicola, a specialist Brassica pathogens, as model organism. Exposure of the fungus to isothiocyanates led to a decreased oxygen consumption rate, intracellular accumulation of reactive oxygen species and mitochondrial-membrane depolarization. We also found that two major regulators of the response to oxidative stress, i.e. the MAP kinase AbHog1 and the transcription factor AbAP1, were activated in the presence of isothiocyanates. Once activated by isothiocyanate-derived reactive oxygen species, AbAP1 was found to promote the expression of different oxidative-response genes. This response might play a significant role in the protection of the fungus against isothiocyanates as mutants deficient in AbHog1 or AbAP1 were found to be hypersensitive to these metabolites. Moreover, the loss of these genes was accompanied by a significant decrease in aggressiveness on Brassica. We suggest that the robust protection response against isothiocyanate-derived oxidative stress might be a key adaptation mechanism for successful infection of host plants by Brassicaceae-specialist necrotrophs like A. brassicicola.

Effects of Lectins on initial attachment of cariogenic Streptococcus mutans.

Science.gov (United States)

Ito, Takashi; Yoshida, Yasuhiro; Shiota, Yasuyoshi; Ito, Yuki; Yamamoto, Tadashi; Takashiba, Shogo

2018-02-01

Oral bacteria initiate biofilm formation by attaching to tooth surfaces via an interaction of a lectin-like bacterial protein with carbohydrate chains on the pellicle. This study aimed to find naturally derived lectins that inhibit the initial attachment of a cariogenic bacterial species, Streptococcus mutans (S. mutans), to carbohydrate chains in saliva in vitro. Seventy kinds of lectins were screened for candidate motifs that inhibit the attachment of S. mutans ATCC 25175 to a saliva-coated culture plate. The inhibitory effect of the lectins on attachment of the S. mutans to the plates was quantified by crystal violet staining, and the biofilm was observed under a scanning electron microscope (SEM). Surface plasmon resonance (SPR) analysis was performed to examine the binding of S. mutans to carbohydrate chains and the binding of candidate lectins to carbohydrate chains, respectively. Moreover, binding assay between the biotinylated-lectins and the saliva components was conducted to measure the lectin binding. Lectins recognizing a salivary carbohydrate chain, Galβ1-3GalNAc, inhibited the binding of S. mutans to the plate. In particular, Agaricus bisporus agglutinin (ABA) markedly inhibited the binding. This inhibition was confirmed by SEM observation. SPR analysis indicated that S. mutans strongly binds to Galβ1-3GalNAc, and ABA binds to Galβ1-3GalNAc. Finally, the biotinylated Galβ1-3GalNAc-binding lectins including ABA demonstrated marked binding to the saliva components. These results suggest that ABA lectin inhibited the attachment of S. mutans to Galβ1-3GalNAc in saliva and ABA can be useful as a potent inhibitor for initial attachment of oral bacteria and biofilm formation.

Lessons learned from mice deficient in lectin complement pathway molecules

DEFF Research Database (Denmark)

Genster, Ninette; Takahashi, Minoru; Sekine, Hideharu

2014-01-01

in turn activate downstream complement components, ultimately leading to elimination of the pathogen. Mice deficient in the key molecules of lectin pathway of complement have been generated in order to build knowledge of the molecular mechanisms of the lectin pathway in health and disease. Despite......The lectin pathway of the complement system is initiated when the pattern-recognition molecules, mannose-binding lectin (MBL), ficolins or collectin-11, bind to invading pathogens or damaged host cells. This leads to activation of MBL/ficolin/collectin-11 associated serine proteases (MASPs), which...... differences in the genetic arrangements of murine and human orthologues of lectin pathway molecules, the knockout mice have proven to be valuable models to explore the effect of deficiency states in humans. In addition, new insight and unexpected findings on the diverse roles of lectin pathway molecules...

Italian multicentre study on intrathecal fluorescein for craniosinusal fistulae.

Science.gov (United States)

Felisati, G; Bianchi, A; Lozza, P; Portaleone, S

2008-08-01

Cerebrospinal fluid leak (CSF), clinical sign of a dural lesion of the skull base, is a relatively rare event that can present with a variety of symptoms. Every craniosinus fistula should be considered a serious, potentially life-threatening situation (even those cases with hidden CSF leak). Reports of experience concerning diagnosis and treatment of craniosinus fistulae have appeared in the Literature. In the last few years, the endoscopic nasal approach is proving effective as it makes diagnosis much easier and is the least invasive surgical approach, with the greatest percentage of success. Various classifications are being proposed to improve clinical evaluation of CSF leaks and to simplify the diagnostic and therapeutic approach. The most common parameters of classification are: aetiology (traumatic, iatrogenic, non-traumatic, etc.) site, type of flow (high or low pressure) and, as far as concerns treatment, the type of graft used, all of which have contributed to various diagnostic and therapeutic algorithms being proposed. Therefore, the subject seems to be widely schematized and the therapeutic attitude widely agreed. However, one of the diagnostic and therapeutic approaches is now being questioned. For some, it is the heart of the clinical approach, while for others, it is a useful tool yet too dangerous to be used on account of potential side effects: namely, the fluorescein test. This procedure, consisting of intrathecal injection of a colorant (fluorescein), is well known by the Food and Drug Administration (FDA) which neither explicitly prohibits it, nor allows it, intrathecal administration is, therefore, an off label use. As far as the Authors know, authorization of this procedure has not been forthcoming anywhere in the world although the procedure itself is widely employed. As far as concerns the use of intrathecal fluorescein, many scientific papers have been written, clearly supporting its clinical usefulness. One limit to the use of fluorescein

Immunologically related lectins from stems and roots of developing seedlings of Cucurbita ficifolia: purification and some properties of root and stem lectins

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Irena Lorenc-Kubis

2014-01-01

Full Text Available Hemagglutinating activity has been found in acetate extracts from roots and stems of squash seedlings (Cucurbita ficifolia. The hemaglutinating activity changes during seeds germination and seedling development. Dot blot and Western blot techniques have shown that proteins from these vegetative tissues cross-reacted with antibodies raised against endogenous cotyledons lectin CLBa and Con A.Lectins were isolated from stems and roots of 6-day old seedlings by precipitation with ethanol, affinity chromatography on Con A-Sepharose, gel filtration on Bio-gel P100 and separated by electrophoresis on polyacrylamide gel. Three purified lectins (RLA1, RLA2, RLA3 were obtained from roots and four from stems (SLA1, SLA2, SLA3, SLA4. The purified lectins from roots and stems agglutinated all human red blood cells, but sheep erythrocytes were most sensitive to agglutination. The hemagglutination of the root lectins RLA2 and RLA3 was inhibited by a very low concentration of arabinose, while RLA1, of xylose and Ga1NAc. Arabinose and Xylose were also found to be the most effective inhibitors of all stem lectins.

A L-type lectin gene is involved in the response to hormonal treatment and water deficit in Volkamer lemon.

Science.gov (United States)

Vieira, Dayse Drielly Sousa Santana; Emiliani, Giovanni; Bartolini, Paola; Podda, Alessandra; Centritto, Mauro; Luro, François; Carratore, Renata Del; Morillon, Raphaël; Gesteira, Abelmon; Maserti, Biancaelena

2017-11-01

Combination of biotic and abiotic stress is a major challenge for crop and fruit production. Thus, identification of genes involved in cross-response to abiotic and biotic stress is of great importance for breeding superior genotypes. Lectins are glycan-binding proteins with a functions in the developmental processes as well as in the response to biotic and abiotic stress. In this work, a lectin like gene, namely ClLectin1, was characterized in Volkamer lemon and its expression was studied in plants exposed to either water stress, hormonal elicitors (JA, SA, ABA) or wounding to understand whether this gene may have a function in the response to multiple stress combination. Results showed that ClLectin1 has 100% homology with a L-type lectin gene from C. sinensis and the in silico study of the 5'UTR region showed the presence of cis-responsive elements to SA, DRE2 and ABA. ClLectin1 was rapidly induced by hormonal treatments and wounding, at local and systemic levels, suggesting an involvement in defence signalling pathways and a possible role as fast detection biomarker of biotic stress. On the other hand, the induction of ClLectin1 by water stress pointed out a role of the gene in the response to drought. The simultaneous response of ClLectin1 expression to water stress and SA treatment could be further investigated to assess whether a moderate drought stress may be useful to improve citrus performance by stimulating the SA-dependent response to biotic stress. Copyright © 2017 Elsevier GmbH. All rights reserved.

The identification of plant lectins with mucosal adjuvant activity

Science.gov (United States)

Lavelle, E C; Grant, G; Pusztai, A; Pfüller, U; O'hagan, D T

2001-01-01

To date, the most potent mucosal vaccine adjuvants to be identified have been bacterial toxins. The present data demonstrate that the type 2 ribosome-inactivating protein (type 2 RIP), mistletoe lectin I (ML-I) is a strong mucosal adjuvant of plant origin. A number of plant lectins were investigated as intranasal (i.n.) coadjuvants for a bystander protein, ovalbumin (OVA). As a positive control, a potent mucosal adjuvant, cholera toxin (CT), was used. Co-administration of ML-I or CT with OVA stimulated high titres of OVA-specific serum immunoglobulin G (IgG) in addition to OVA-specific IgA in mucosal secretions. CT and ML-I were also strongly immunogenic, inducing high titres of specific serum IgG and specific IgA at mucosal sites. None of the other plant lectins investigated significantly boosted the response to co-administered OVA. Immunization with phytohaemagglutinin (PHA) plus OVA elicited a lectin-specific response but did not stimulate an enhanced response to OVA compared with the antigen alone. Intranasal delivery of tomato lectin (LEA) elicited a strong lectin-specific systemic and mucosal antibody response but only weakly potentiated the response to co-delivered OVA. In contrast, administration of wheatgerm agglutinin (WGA) or Ulex europaeus lectin 1 (UEA-I) with OVA stimulated a serum IgG response to OVA while the lectin-specific responses (particularly for WGA) were relatively low. Thus, there was not a direct correlation between immunogenicity and adjuvanticity although the strongest adjuvants (CT, ML-I) were also highly immunogenic. PMID:11168640

The search for lectin isolated from the mycelial cultures of Laetiporus sulphureus

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Grażyna Końska

2014-08-01

Full Text Available This study proved the presence of lectin in mycelial cultures of Laetiporus sulphureus. Lectin was excreted into the medium and its erythroagglutinating activity was not high. No active lectin was detected in hyphae using both extraction and immunofluorescence method. Comparative studies based on immunological methods indicate~ that the lectin synthesised in vitro differed from the lectin produced in fruit-bodies.

Molecular Morphology of Pituitary Cells, from Conventional Immunohistochemistry to Fluorescein Imaging

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R. Yoshiyuki Osamura

2011-04-01

Full Text Available In situ hybridization (ISH at the electron microscopic (EM level is essential for elucidating the intracellular distribution and role of mRNA in protein synthesis. EM-ISH is considered to be an important tool for clarifying the intracellular localization of mRNA and the exact site of pituitary hormone synthesis on the rough endoplasmic reticulum. A combined ISH and immunohistochemistry (IHC under EM (EM-ISH&IHC approach has sufficient ultrastructural resolution, and provides two-dimensional images of the subcellular localization of pituitary hormone and its mRNA in a pituitary cell. The advantages of semiconductor nanocrystals (quantum dots, Qdots and confocal laser scanning microscopy (CLSM enable us to obtain three-dimensional images of the subcellular localization of pituitary hormone and its mRNA. Both EM-ISH&IHC and ISH & IHC using Qdots and CLSM are useful for understanding the relationships between protein and mRNA simultaneously in two or three dimensions. CLSM observation of rab3B and SNARE proteins such as SNAP-25 and syntaxin has revealed that both rab3B and SNARE system proteins play important roles and work together as the exocytotic machinery in anterior pituitary cells. Another important issue is the intracellular transport and secretion of pituitary hormone. We have developed an experimental pituitary cell line, GH3 cell, which has growth hormone (GH linked to enhanced yellow fluorescein protein (EYFP. This stable GH3 cell secretes GH linked to EYFP upon stimulation by Ca2+ influx or Ca2+ release from storage. This GH3 cell line is useful for the real-time visualization of the intracellular transport and secretion of GH. These three methods from conventional immunohistochemistry and fluorescein imaging allow us to consecutively visualize the process of transcription, translation, transport and secretion of anterior pituitary hormone.

Sugared biomaterial binding lectins: achievements and perspectives

Czech Academy of Sciences Publication Activity Database

Bojarová, Pavla; Křen, Vladimír

2016-01-01

Roč. 4, č. 8 (2016), s. 1142-1160 ISSN 2047-4830 R&D Projects: GA ČR GC15-02578J Institutional support: RVO:61388971 Keywords : C-TYPE LECTINS * AMPHIPHILIC JANUS GLYCODENDRIMERS * BIOMEDICALLY RELEVANT LECTINS Subject RIV: CE - Biochemistry Impact factor: 4.210, year: 2016

Optimizing isothiocyanate formation during enzymatic glucosinolate breakdown by adjusting pH value, temperature and dilution in Brassica vegetables and Arabidopsis thaliana

Science.gov (United States)

Hanschen, Franziska S.; Klopsch, Rebecca; Oliviero, Teresa; Schreiner, Monika; Verkerk, Ruud; Dekker, Matthijs

2017-01-01

Consumption of glucosinolate-rich Brassicales vegetables is associated with a decreased risk of cancer with enzymatic hydrolysis of glucosinolates playing a key role. However, formation of health-promoting isothiocyanates is inhibited by the epithiospecifier protein in favour of nitriles and epithionitriles. Domestic processing conditions, such as changes in pH value, temperature or dilution, might also affect isothiocyanate formation. Therefore, the influences of these three factors were evaluated in accessions of Brassica rapa, Brassica oleracea, and Arabidopsis thaliana. Mathematical modelling was performed to determine optimal isothiocyanate formation conditions and to obtain knowledge on the kinetics of the reactions. At 22 °C and endogenous plant pH, nearly all investigated plants formed nitriles and epithionitriles instead of health-promoting isothiocyanates. Response surface models, however, clearly demonstrated that upon change in pH to domestic acidic (pH 4) or basic pH values (pH 8), isothiocyanate formation considerably increases. While temperature also affects this process, the pH value has the greatest impact. Further, a kinetic model showed that isothiocyanate formation strongly increases due to dilution. Finally, the results show that isothiocyanate intake can be strongly increased by optimizing the conditions of preparation of Brassicales vegetables.

Current status of lectin-based cancer diagnosis and therapy

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Fohona S. Coulibaly

2017-01-01

Full Text Available Lectins are carbohydrate recognizing proteins originating from diverse origins in nature, including animals, plants, viruses, bacteria and fungus. Due to their exceptional glycan recognition property, they have found many applications in analytical chemistry, biotechnology and surface chemistry. This manuscript explores the current use of lectins for cancer diagnosis and therapy. Moreover, novel drug delivery strategies aiming at improving lectin’s stability, reducing their undesired toxicity and controlling their non-specific binding interactions are discussed. We also explore the nanotechnology application of lectins for cancer targeting and imaging. Although many investigations are being conducted in the field of lectinology, there is still a limited clinical translation of the major findings reported due to lectins stability and toxicity concerns. Therefore, new investigations of safe and effective drug delivery system strategies for lectins are warranted in order to take full advantage of these proteins.

Burn injury reveals altered phenotype in mannan-binding lectin-deficient mice

DEFF Research Database (Denmark)

Møller-Kristensen, Mette; Hamblin, Michael R; Thiel, Steffen

2007-01-01

Burn injury destroys skin, the second largest innate immune organ in the body, and triggers chaotic immune and inflammatory responses. The pattern recognition molecule, mannan-binding lectin (MBL), plays an important role in the first-line host defense against infectious agents. MBL initiates...... the lectin complement pathway and acts as an opsonin. Recent studies suggest that MBL also modulates inflammatory responses. We report that local responses after burn in MBL null mice differ from those found in wild-type (WT) mice in the following important biological markers: spontaneous eschar separation......, thinned epidermis and dermis, upregulation of soluble factors including cytokines, chemokines, cell adhesion molecules, a growth factor-binding protein, and matrix metalloproteinases. Mice lacking C1q, C4, or C3 did not show the lack of eschar separation seen in MBL null-burn phenotype. These findings...

Ultrasonic irradiation enhanced the ability of Fluorescein-DA-Fe(III) on sonodynamic and sonocatalytic damages of DNA molecules.

Science.gov (United States)

Wu, Qiong; Chen, Xia; Jia, Lizhen; Wang, Yi; Sun, Ying; Huang, Xingjun; Shen, Yuxiang; Wang, Jun

2017-11-01

The interaction of DNA with Bis [N,N-bis (carboxymethyl) aminomethyl] fluorescein-Ferrous(III) (Fluorescein-DA-Fe(III)) with dual functional (sonodynamic and sonocatalytic) activity was studied by UV-vis spectroscopy, fluorescence spectroscopy, FT-IR spectroscopy, circular dichroism (CD) spectroscopy and viscosity measurements. And then, the damage of DNA caused by Fluorescein-DA-Fe(III) under ultrasonic irradiation (US) was researched by agarose gel electrophoresis and cytotoxicity assay. Meanwhile, some influenced factors such as ultrasonic irradiation time and Fluorescein-DA-Fe(III) concentration on the damage degree of DNA molecules were also examined. As a control, for Bis [N,N-bis (carboxymethyl) aminomethyl] fluorescein (Fluorescein-DA), the same experiments were carried out. The results showed that both Fluorescein-DA-Fe(III) and Fluorescein-DA can interact with DNA molecules. Under ultrasonic irradiation, Fluorescein-DA shows sonodynamic activity, which can damage DNA molecules. While, in the presence of Fe(III) ion, the Fluorescein-DA-Fe(III) displays not only sonodynamic activity but also sonocatalytic activity under ultrasonic irradiation, which injures DNA more serious than Fluorescein-DA. The researches confirmed the dual function (sonodynamic activity and sonocatalytic activity) of Fluorescein-DA-Fe(III) and expanded the usage of Fluorescein-DA-Fe(III) as a sonosensitizer in sonodynamic therapy (SDT). Copyright © 2017 Elsevier B.V. All rights reserved.

Assessing Natural Isothiocyanate Air Emissions after Field Incorporation of Mustard Cover Crop

Energy Technology Data Exchange (ETDEWEB)

Trott, Donna M.; LePage, Jane; Hebert, Vincent

2012-01-01

A regional air assessment was performed to characterize volatile natural isothiocyanate (NITC) compounds in air during soil incorporation of mustard cover crops in Washington State. Field air sampling and analytical methods were developed specific to three NITCs known to be present in air at appreciable concentrations during/after field incorporation. The maximum observed concentrations in air for the allyl, benzyl, and phenethyl isothiocyanates were respectively 188, 6.1, and 0.7 lg m-3 during mustard incorporation. Based on limited inhalation toxicity information, airborne NITC concentrations did not appear to pose an acute human inhalation exposure concern to field operators and bystanders.

Lectins binding during alloxan-induced diabetes in rat soleus muscle

African Journals Online (AJOL)

Membrane structural changes of soleus muscle of alloxan-diabetic rats were detected with a panel of six biotinylated lectins. Samples of muscles were obtained from normal and diabetic rats. The biotinylated lectins in staining were detected by avidin-peroxidase complex. Lectin stainning of soleus muscle cryostat sections ...

Mannan-binding lectin and healing of a radiation-induced chronic ulcer--a case report on mannan-binding lectin replacement therapy

DEFF Research Database (Denmark)

Maaløe, Nanna; Bonde, C; Laursen, I

2011-01-01

Mannan-binding lectin is an important component of innate immunity, and insufficiency is associated with several clinical disorders. Recently, experimental replacement therapy with plasma-derived mannan-binding lectin has become an option. The current article presents the case of a patient with a...

Characterizing the glycocalyx of poultry spermatozoa: III. Semen cryopreservation methods alter the carbohydrate component of rooster sperm membrane glycoconjugates.

Science.gov (United States)

Peláez, J; Bongalhardo, D C; Long, J A

2011-02-01

The carbohydrate-rich zone on the sperm surface is essential for inmunoprotection in the female tract and early gamete interactions. We recently have shown the glycocalyx of chicken sperm to be extensively sialylated and to contain residues of mannose, glucose, galactose, fucose, N-acetyl-galactosamine, N-acetyl-glucosamine, and N-acetyl-lactosamine. Our objective here was to evaluate the effects of 3 different cryopreservation methods on the sperm glycocalyx. Semen from roosters was pooled, diluted, cooled to 5°C, and aliquoted for cryopreservation using 6% dimethylacetamide (DMA), 11% dimethylsulfoxide (DMSO), or 11% glycerol (GOH). For the DMA method, semen was equilibrated for 1 min with cryoprotectant and rapidly frozen by dropping 25-µL aliquots into liquid nitrogen. For the other methods, semen was equilibrated for either 1 min (DMSO) or 20 min (GOH), loaded into straws, and frozen with a programmable freezer. Thawing rates mimicked the freezing rates (e.g., rapid for DMA; moderate for DMSO and GOH). Aliquots of thawed and fresh, unfrozen semen were incubated with 1 of 12 fluorescein isothiocyanate-conjugated lectins and counterstained with propidium iodide, and mean fluorescence intensity (MFI) was assessed by flow cytometry. For each lectin, the MFI of propidium iodide-negative (viable sperm) was compared among the fresh and frozen-thawed treatments (n = 5). For sperm frozen with GOH and DMA, the MFI of most lectins was similar (P > 0.05) to that of fresh sperm, whereas only 5 of 12 lectins were similar between fresh and DMSO-frozen sperm. Sperm from all 3 methods had higher (P < 0.05) MFI for lectins specific for N-acetyl-glucosamine and β-galactose than did fresh sperm. Fewer sperm were damaged (P < 0.001) with GOH than with DMA or DMSO, and membrane integrity was correlated with MFI for 9 of 12 lectins (P < 0.05). These data indicate that surface carbohydrates are altered during cryopreservation, and that cryoprotectant type and freezing

Human Lectins and Their Roles in Viral Infections

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Christopher P. Mason

2015-01-01

Full Text Available Innate recognition of virus proteins is an important component of the immune response to viral pathogens. A component of this immune recognition is the family of lectins; pattern recognition receptors (PRRs that recognise viral pathogen-associated molecular patterns (PAMPs including viral glycoproteins. In this review we discuss the contribution of soluble and membrane-associated PRRs to immunity against virus pathogens, and the potential role of these molecules in facilitating virus replication. These processes are illustrated with examples of viruses including human immunodeficiency virus (HIV, hepatitis C virus (HCV and Ebola virus (EBOV. We focus on the structure, function and genetics of the well-characterised C-type lectin mannose-binding lectin, the ficolins, and the membrane-bound CD209 proteins expressed on dendritic cells. The potential for lectin-based antiviral therapies is also discussed.

Characterization of chickpea (Cicer arietinum L.) lectin for biological activity.

Science.gov (United States)

Gautam, Ajay Kumar; Gupta, Neha; Narvekar, Dakshita T; Bhadkariya, Rajni; Bhagyawant, Sameer S

2018-05-01

Lectins are proteins that are subject of intense investigations. Information on lectin from chickpea ( Cicer arietinum L.) with respect to its biological activities are very limited. In this study, we purified lectin from the seeds of chickpea employing DEAE-cellulose and SP-Sephadex ion exchange chromatography and identified its molecular subunit mass as 35 kDa. The free radical scavenging activity of lectin measured by the DPPH assay has IC 50 of 0.88 µg/mL. Lectin exerted antifungal activity against Candida krusei , Fusarium oxysporium oxysporium , Saccharomyces cerevisiae and Candida albicans , while antibacterial activity against E. coli , B. subtilis , S. marcescens and P. aeruginosa. The minimum inhibitory concentrations were 200, 240, 160 and 140 µg for C. krusei, F. oxysporium , S. cerevisiae and C. albicans respectively. Lectin was further examined for its antiproliferative potential against cancerous cell line. The cell viability assay indicated a high inhibition activity on Ishikawa, HepG2, MCF-7 and MDA-MB-231 with IC 50 value of 46.67, 44.20, 53.58 and 37.46 µg/mL respectively. These results can provide a background for future research into the benefits of chickpea lectin to pharmacological perspective.

Propargylamine-isothiocyanate reaction: efficient conjugation chemistry in aqueous media

DEFF Research Database (Denmark)

Viart, Helene Marie-France; Larsen, T. S.; Tassone, Chiara

2014-01-01

A coupling reaction between secondary propargyl amines and isothiocyanates in aqueous media is described. The reaction is high-yielding and affords cyclized products within 2-24 h. A functionalized ether lipid was synthesized in 8 steps, formulated as liposomes with POPC and conjugated to FITC un...

Animal lectins: potential receptors for ginseng polysaccharides

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So Hee Loh

2017-01-01

Full Text Available Panax ginseng Meyer, belonging to the genus Panax of the family Araliaceae, is known for its human immune system-related effects, such as immune-boosting effects. Ginseng polysaccharides (GPs are the responsible ingredient of ginseng in immunomodulation, and are classified as acidic and neutral GPs. Although GPs participate in various immune reactions including the stimulation of immune cells and production of cytokines, the precise function of GPs together with its potential receptor(s and their signal transduction pathways have remained largely unknown. Animal lectins are carbohydrate-binding proteins that are highly specific for sugar moieties. Among many different biological functions in vivo, animal lectins especially play important roles in the immune system by recognizing carbohydrates that are found exclusively on pathogens or that are inaccessible on host cells. This review summarizes the immunological activities of GPs and the diverse roles of animal lectins in the immune system, suggesting the possibility of animal lectins as the potential receptor candidates of GPs and giving insights into the development of GPs as therapeutic biomaterials for many immunological diseases.

pH-sensitive intracellular photoluminescence of carbon nanotube-fluorescein conjugates in human ovarian cancer cells

International Nuclear Information System (INIS)

Chen, M T; Ishikawa, F N; Gundersen, M A; Gomez, L M; Vernier, P T; Zhou, C

2009-01-01

To add to the understanding of the properties of functionalized carbon nanotubes in biological applications, we report a monotonic pH sensitivity of the intracellular fluorescence emission of single-walled carbon nanotube-fluorescein carbazide (SWCNT-FC) conjugates in human ovarian cancer cells. Light-stimulated intracellular hydrolysis of the amide linkage and localized intracellular pH changes are proposed as mechanisms. SWCNT-FC conjugates may serve as intracellular pH sensors.

In-house preparation of lectin panel and detection of Tn polyagglutination

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Sudipta Sekhar Das

2015-01-01

Full Text Available Polyagglutination is a condition in which red cells are agglutinated by ABO-compatible adult human sera, but not by cord blood sera and may be acquired or inherited. Lectins are invaluable reagents in the investigation of red cells polyagglutination. We prepared in-house lectin panel and confirmed Tn polyagglutination in a pregnant lady. The lady was anemic and refused blood transfusion elsewhere due to serological discrepancy. We found ABO discrepancy and an incompatible minor cross-match in the initial investigation and suspected polyagglutination. Confirmation of polyagglutination was done using adult and cord sera. We then used the in-house lectin panels to detect the type of polyagglutination. The agglutination pattern with the various lectins was suggestive of Tn polyagglutination, which was further supported by the enzyme study. Most blood banks in India lack commercial lectin panels because of cost and procurement difficulty. Lectins play an important role in the diagnosis and differentiation of polyagglutination and immunohematological management of patient. The important and basic lectins can be prepared in-house using specific raw seeds following standardized protocol.

In-house preparation of lectin panel and detection of Tn polyagglutination.

Science.gov (United States)

Das, Sudipta Sekhar

2015-01-01

Polyagglutination is a condition in which red cells are agglutinated by ABO-compatible adult human sera, but not by cord blood sera and may be acquired or inherited. Lectins are invaluable reagents in the investigation of red cells polyagglutination. We prepared in-house lectin panel and confirmed Tn polyagglutination in a pregnant lady. The lady was anemic and refused blood transfusion elsewhere due to serological discrepancy. We found ABO discrepancy and an incompatible minor cross-match in the initial investigation and suspected polyagglutination. Confirmation of polyagglutination was done using adult and cord sera. We then used the in-house lectin panels to detect the type of polyagglutination. The agglutination pattern with the various lectins was suggestive of Tn polyagglutination, which was further supported by the enzyme study. Most blood banks in India lack commercial lectin panels because of cost and procurement difficulty. Lectins play an important role in the diagnosis and differentiation of polyagglutination and immunohematological management of patient. The important and basic lectins can be prepared in-house using specific raw seeds following standardized protocol.

Neuronal Mechanisms and Bloodflow Control of Infrared Reception in Snakes

National Research Council Canada - National Science Library

Goris, Richard

2004-01-01

...) radiation to improve image resolution. Fluorescein isothiocyanate (FlTC) dextran together with fluorescent microspheres was introduced into the blood stream and pit bloodflow was viewed with a fluorescence microscope and CCD camera...

Lectin of Bacillus subtilis sp. as overinducer of gamma-interferonogenesis.

Science.gov (United States)

Kishko, Ia H; Vasylenko, M I; Pidhors'kyĭ, V S; Kovalenko, E O

1997-01-01

It has been demonstrated experimentally that lectin of Bacillus subtilis sp. in comparison with generally accepted Con A, PHA and lectin of "gold rain" grass--Laburnum anagyroides M e d i k in trials on white mice of CBA line gave in 4 hours of induction maximal titers of gamma-IFN in blood serum of animals--153.6 +/- 17.0 IU/ml. Practically identical titers had been obtained after induction by lectin "gold rain", some lower--after Con A and PHA. At swine gamma-IFN synthesis optimal density of cell suspension must contain 2.5 + 10(7) immunocytes in 1 ml, owing to which it is possible to obtain the titer equal 1 : 2150. Materials with using of bacterial lectins at various degree of purification had shown that maximal titers in blood serum of mongrel white mice were registered at administration to animals of non-purified lectin, 4 times lower--at using of half-purified and purified lectins. Data of these trials in vivo were confirmed by materials of gamma-IFN induction by immunocytes of swine, cattle and even man.

Rapid method for measuring protease activity in milk using radiolabeled casein

International Nuclear Information System (INIS)

Christen, G.L.

1987-01-01

A rapid means to detect the presence of protease activity in raw milk could be useful in predicting keeping ability of products made from that milk. A 30-min assay has been developed and compared with three other methods of detecting protease. Casein, [methyl- 14 C]-methylated-alpha was purchased from a radioisotope supplier. Concentrations of substrate from 2 to 20 nCi gave counts per minute, which increased linearly when counted with the Charm analyzer. There was not a significant difference in counting times of 10, 20, or 30 min. A mixture of sodium acetate and acetic acid precipitated nonhydrolyzed substrate with an efficiency of 97%. Comparison of the [ 14 C] casein assay, a casein fluorescein isothiocyanate assay, trinitrobenzenesulfonic acid procedure, and the Hull procedure using protease from psychrotrophic bacteria revealed that the [ 14 C] casein and casein fluorescein isothiocyanate methods were roughly equivalent and that the radiometric procedure was 10 times more sensitive than the trinitrobenzenesulfonic acid assay. The radiometric procedure was approximately 10(4) times more sensitive than the Hull procedure. The [ 14 C] casein and casein fluorescein isothiocyanate methods were similar in time required, about 30 min, while the trinitrobenzenesulfonic acid assay and Hull method required about 1 h plus reagent preparation time. The [ 14 C] casein procedure was most expensive per test; the other three were cheaper and similar to each other in cost

Synthesis of taurine–fluorescein conjugate and evaluation of its retina-targeted efficiency in vitro

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Meihong Huang

2014-12-01

Full Text Available In this work, retinal penetration of fluorescein was achieved in vitro by covalent attachment of taurine to fluorescein, yielding the F–Tau conjugate. Nuclear magnetic resonance (NMR and high resolution mass spectrometry (HRMS were used to confirm the successful synthesis of F–Tau. The cellular uptake of F–Tau in adult retinal pigment epithelial cells (ARPE-19 and human retinal microvascular endothelial cells (hRMECs was visualized via confocal scanning microscopy. The results indicated an improvement of solubility and a reduction of logP of F–Tau compared with fluorescein. As compared with fluorescein, F–Tau showed little toxicity, and was retained longer by cells in uptake experiments. F–Tau also displayed higher transepithelial permeabilities than fluorescein in ARPE-19 and hRMECs monolayer cells (P<0.05. These results showed that taurine may be a useful ligand for targeting small-molecule hydrophobic pharmaceuticals into the retina.

Comparison of eosin and fluorescein conjugates for the photoinitiation of cell-compatible polymer coatings.

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Jacob L Lilly

Full Text Available Targeted photopolymerization is the basis for multiple diagnostic and cell encapsulation technologies. While eosin is used in conjunction with tertiary amines as a water-soluble photoinitiation system, eosin is not widely sold as a conjugate with antibodies and other targeting biomolecules. Here we evaluate the utility of fluorescein-labeled bioconjugates to photopolymerize targeted coatings on live cells. We show that although fluorescein conjugates absorb approximately 50% less light energy than eosin in matched photopolymerization experiments using a 530 nm LED lamp, appreciable polymer thicknesses can still be formed in cell compatible environments with fluorescein photosensitization. At low photoinitiator density, eosin allows more sensitive initiation of gelation. However at higher functionalization densities, the thickness of fluorescein polymer films begins to rival that of eosin. Commercial fluorescein-conjugated antibodies are also capable of generating conformal, protective coatings on mammalian cells with similar viability and encapsulation efficiency as eosin systems.

Comparison of eosin and fluorescein conjugates for the photoinitiation of cell-compatible polymer coatings.

Science.gov (United States)

Lilly, Jacob L; Gottipati, Anuhya; Cahall, Calvin F; Agoub, Mohamed; Berron, Brad J

2018-01-01

Targeted photopolymerization is the basis for multiple diagnostic and cell encapsulation technologies. While eosin is used in conjunction with tertiary amines as a water-soluble photoinitiation system, eosin is not widely sold as a conjugate with antibodies and other targeting biomolecules. Here we evaluate the utility of fluorescein-labeled bioconjugates to photopolymerize targeted coatings on live cells. We show that although fluorescein conjugates absorb approximately 50% less light energy than eosin in matched photopolymerization experiments using a 530 nm LED lamp, appreciable polymer thicknesses can still be formed in cell compatible environments with fluorescein photosensitization. At low photoinitiator density, eosin allows more sensitive initiation of gelation. However at higher functionalization densities, the thickness of fluorescein polymer films begins to rival that of eosin. Commercial fluorescein-conjugated antibodies are also capable of generating conformal, protective coatings on mammalian cells with similar viability and encapsulation efficiency as eosin systems.

Differential effect of plant lectins on mast cells of different origins

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F.C. Lopes

2005-06-01

Full Text Available Histamine release induced by plant lectins was studied with emphasis on the carbohydrate specificity, external calcium requirement, metal binding sites, and mast cell heterogeneity and on the importance of antibodies bound to the mast cell membrane to the lectin effect. Peritoneal mast cells were obtained by direct lavage of the rat peritoneal cavity and guinea pig intestine and hamster cheek pouch mast cells were obtained by dispersion with collagenase type IA. Histamine release was induced with concanavalin A (Con A, lectins from Canavalia brasiliensis, mannose-specific Cymbosema roseum, Maackia amurensis, Parkia platycephala, Triticum vulgaris (WGA, and demetallized Con A and C. brasiliensis, using 1-300 µg/ml lectin concentrations applied to Wistar rat peritoneal mast cells, peaking on 26.9, 21.0, 29.1, 24.9, 17.2, 10.7, 19.9, and 41.5%, respectively. This effect was inhibited in the absence of extracellular calcium. The lectins were also active on hamster cheek pouch mast cells (except demetallized Con A and on Rowett nude rat (animal free of immunoglobulins peritoneal mast cells (except for mannose-specific C. roseum, P. platycephala and WGA. No effect was observed in guinea pig intestine mast cells. Glucose-saturated Con A and C. brasiliensis also released histamine from Wistar rat peritoneal mast cells. These results suggest that histamine release induced by lectins is influenced by the heterogeneity of mast cells and depends on extracellular calcium. The results also suggest that this histamine release might occur by alternative mechanisms, because the usual mechanism of lectins is related to their binding properties to metals from which depend the binding to sugars, which would be their sites to bind to immunoglobulins. In the present study, we show that the histamine release by lectins was also induced by demetallized lectins and by sugar-saturated lectins (which would avoid their binding to other sugars. Additionally, the lectins

Lectins stain cells differentially in the coral, Montipora capitata

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Work, Thierry M.; Farah, Yael

2014-01-01

A limitation in our understanding of coral disease pathology and cellular pathogenesis is a lack of reagents to characterize coral cells. We evaluated the utility of plant lectins to stain tissues of a dominant coral, Montipora capitata, from Hawaii. Of 22 lectins evaluated, nine of these stained structures in the upper or basal body wall of corals. Specific structures revealed by lectins that were not considered distinct or evident on routine hematoxylin and eosin sections of coral tissues included apical and basal granules in gastrodermis and epidermis, cnidoglandular tract and actinopharynx cell surface membranes, capsules of mature holotrichous isorhizas, and perivitelline and periseminal cells. Plant lectins could prove useful to further our understanding of coral physiology, anatomy, cell biology, and disease pathogenesis.

Insights into Animal and Plant Lectins with Antimicrobial Activities

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Renata de Oliveira Dias

2015-01-01

Full Text Available Lectins are multivalent proteins with the ability to recognize and bind diverse carbohydrate structures. The glyco -binding and diverse molecular structures observed in these protein classes make them a large and heterogeneous group with a wide range of biological activities in microorganisms, animals and plants. Lectins from plants and animals are commonly used in direct defense against pathogens and in immune regulation. This review focuses on sources of animal and plant lectins, describing their functional classification and tridimensional structures, relating these properties with biotechnological purposes, including antimicrobial activities. In summary, this work focuses on structural-functional elucidation of diverse lectin groups, shedding some light on host-pathogen interactions; it also examines their emergence as biotechnological tools through gene manipulation and development of new drugs.

Toxicity and Binding Profile of Lectins from the Genus Canavalia on Brine Shrimp

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Francisco Vassiliepe Sousa Arruda

2013-01-01

Full Text Available Lectins are sugar-binding proteins widely distributed in nature with many biological functions. Although many lectins have a remarkable biotechnological potential, some of them can be cytotoxic. Thus, the aim of this study was to assess the toxicity of five lectins, purified from seeds of different species of Canavalia genus. In order to determine the toxicity, assays with Artemia nauplii were performed. In addition, a fluorescence assay was carried out to evaluate the binding of lectins to Artemia nauplii. In order to verify the relationship between the structure of lectins and their cytotoxic effect, structural analysis was carried out to evaluate the volume of the carbohydrate recognition domain (CRD of each lectin. The results showed that all lectins exhibited different toxicities and bound to a similar area in the digestive tract of Artemia nauplii. Concerning the structural analysis, differences in spatial arrangement and volume of CRD may explain the variation of the toxicity exhibited by each lectin. To this date, this is the first study that establishes a link between toxicity and structure of CRD from Diocleinae lectins.

Bauhinia variegata var. variegata lectin: isolation, characterization, and comparison.

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Chan, Yau Sang; Ng, Tzi Bun

2015-01-01

Bauhinia variegata var. variegata seeds are rich in proteins. Previously, one of the major storage proteins of the seeds was found to be a trypsin inhibitor that possessed various biological activities. By using another purification protocol, a glucoside- and galactoside-binding lectin that demonstrated some differences from the previously reported B. variegata lectin could be isolated from the seeds. It involved affinity chromatography on Affi-gel blue gel, ion exchange chromatography on Q-Sepharose and Mono Q, and also size exclusion chromatography on Superdex 75. The lectin was not retained on Affi-gel blue gel but interacted with Q-Sepharose. The lectin was a 64-kDa protein with two 32-kDa subunits. It had low thermostability (stable up to 50 °C) and moderate pH stability (stable in pH 3-10). It exhibited anti-proliferative activity on nasopharyngeal carcinoma HONE1 cells with an IC50 of 12.8 μM after treatment for 48 h. It also slightly inhibited the growth of hepatoma HepG2 cells. The lectin may have potential in aiding cancer treatments.

Retcam fluorescein gonioangiography: a new modality for early detection of angle neovascularization in diabetic retinopathy.

Science.gov (United States)

Azad, Rajvardhan; Arora, Tarun; Sihota, Ramanjit; Chandra, Parijat; Mahajan, Deepankur; Sain, Siddarth; Sharma, Yograj

2013-10-01

To evaluate the role of Retcam fluorescein gonioangiography in detecting neovascularization of the angle and correlate the same with gonioscopy in diabetic retinopathy. One hundred and fifty eyes of 150 patients (25 each of mild, moderate, severe, very severe nonproliferative diabetic retinopathy (NPDR) proliferative diabetic retinopathy (PDR); and PDR with high-risk characteristics) were recruited. They underwent complete ocular examination including applanation tonometry, gonioscopy, Retcam fluorescein gonioangiography, and fundus fluorescein angiography. Using Retcam fluorescein gonioangiography, of 150 eyes neovascularization of the angle was detected in 37 eyes (24.66%) compared with 22 eyes (14.66%) on gonioscopy (P = 0.04). Small newly formed vessels were evident only with Retcam fluorescein gonioangiography. In 10 of 50 patients (20%) with severe/very severe NPDR, angle neovascularization was appreciable on Retcam fluorescein angiography compared with 5 patients (10%) on gonioscopy. Similarly, 25 of 50 patients (50%) with PDR/PDR with high-risk characteristics had neovascularization of the angle on Retcam gonioangiography compared with 17 (34%) on gonioscopy. Retcam fluorescein gonioangiography is a novel technique for early detection of angle neovascularization in diabetic retinopathy and hence preventing progression to neovascular glaucoma. The objective nature of this test helps in precise decision making compared with gonioscopy for early intervention especially in cases of pre-PDR.

Visualizing the dental biofilm matrix by means of fluorescence lectin-binding analysis

DEFF Research Database (Denmark)

Tawakoli, Pune Nina; Neu, Thomas R; Busck, Mette Marie

2017-01-01

lectins to visualize and quantify extracellular glycoconjugates in dental biofilms. Lectin binding was screened on pooled supragingival biofilm samples collected from 76 subjects using confocal microscopy. FLBA was then performed with 10 selected lectins on biofilms grown in situ for 48 h in the absence......The extracellular matrix is a poorly studied, yet important component of dental biofilms. Fluorescence lectin-binding analysis (FLBA) is a powerful tool to characterize glycoconjugates in the biofilm matrix. This study aimed to systematically investigate the ability of 75 fluorescently labeled......-biofilms: Aleuria aurantia (AAL), Calystega sepiem (Calsepa), Lycopersicon esculentum (LEA), Morniga-G (MNA-G) and Helix pomatia (HPA). No significant correlation between the binding of specific lectins and bacterial composition was found. Fluorescently labeled lectins enable the visualization of glycoconjugates...

Antifungal activity of lectins against yeast of vaginal secretion

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Bruno Severo Gomes

2012-06-01

Full Text Available Lectins are carbohydrate-binding proteins of non-imune origin. This group of proteins is distributed widely in nature and they have been found in viruses, microorganisms, plants and animals. Lectins of plants have been isolated and characterized according to their chemical, physical-chemical, structural and biological properties. Among their biological activities, we can stress its fungicidal action. It has been previously described the effect of the lectins Dviol, DRL, ConBr and LSL obtained from the seeds of leguminous plants on the growth of yeasts isolated from vaginal secretions. In the present work the experiments were carried out in microtiter plates and the results interpreted by both methods: visual observations and a microplate reader at 530nm. The lectin concentrations varied from 0.5 to 256µg/mL, and the inoculum was established between 65-70% of trammitance. All yeast samples isolated from vaginal secretion were evaluated taxonomically, where were observed macroscopic and microscopic characteristics to each species. The LSL lectin did not demonstrate any antifungal activity to any isolate studied. The other lectins DRL, ConBr and DvioL, showed antifungal potential against yeast isolated from vaginal secretion. These findings offering offer a promising field of investigation to develop new therapeutic strategies against vaginal yeast infections, collaborating to improve women's health.

Direct and indirect antioxidant activity of polyphenol- and isothiocyanate-enriched fractions from Moringa oleifera.

Science.gov (United States)

Tumer, Tugba Boyunegmez; Rojas-Silva, Patricio; Poulev, Alexander; Raskin, Ilya; Waterman, Carrie

2015-02-11

Moringa oleifera Lam. is a fast-growing, tropical tree with various edible parts used as nutritious food and traditional medicine. This study describes an efficient preparatory strategy to extract and fractionate moringa leaves by fast centrifugal partition chromatography (FCPC) to produce polyphenol and isothiocyanate (ITC) rich fractions. Characterization and further purification of these fractions showed that moringa polyphenols were potent direct antioxidants assayed by oxygen radical absorbance capacity (ORAC), whereas moringa ITCs were effective indirect antioxidants assayed by induction of NAD(P)H quinone oxidoreductase 1 (NQO1) activity in Hepa1c1c7 cells. In addition, purified 4-[(α-l-rhamnosyloxy)benzyl]isothiocyanate and 4-[(4'-O-acetyl-α-l-rhamnosyloxy)benzyl]isothiocyanate were further evaluated for their ORAC and NQO1 inducer potency in comparison with sulforaphane (SF). Both ITCs were as potent as SF in inducing NQO1 activity. These findings suggest that moringa leaves contain a potent mixture of direct and indirect antioxidants that can explain its various health-promoting effects.

Antitrypanosomal isothiocyanate and thiocarbamate glycosides from Moringa peregrina.

Science.gov (United States)

Ayyari, Mahdi; Salehi, Peyman; Ebrahimi, Samad Nejad; Zimmermann, Stefanie; Portmann, Lena; Krauth-Siegel, R Luise; Kaiser, Marcel; Brun, Reto; Rezadoost, Hassan; Rezazadeh, Shamsali; Hamburger, Matthias

2014-01-01

O-Methyl (1), O-ethyl (2), and O-butyl (3) 4-[(α-L-rhamnosyloxy) benzyl] thiocarbamate (E), along with 4-(α-L-rhamnosyloxy) benzyl isothiocyanate (4) have been isolated from the aerial parts of Moringa peregrina. The compounds were tested for in vitro activity against Trypanosoma brucei rhodesiense and cytotoxicity in rat skeletal myoblasts (L6 cells). The most potent compound was 4 with an IC50 of 0.10 µM against T.b. rhodesiense and a selectivity index of 73, while the thiocarbamate glycosides 1, 2, and 3 showed only moderate activity. Intraperitoneal administration of 50 mg/kg body weight/day of 4 in the T.b. rhodesiense STIB 900 acute mouse model revealed significant in vivo toxicity. Administration of 10 mg/kg body weight/day resulted in a 95% reduction of parasitemia on day 7 postinfection, but did not cure the animals. Because of its high in vitro activity and its ability to irreversibly inhibit trypanothione reductase, an attractive parasite-specific target enzyme, 4-[(α-L-rhamnosyloxy) benzyl] isothiocyanate (4), can be considered as a lead structure for the development and characterization of novel antitrypanosomal drugs. Georg Thieme Verlag KG Stuttgart · New York.

Mannose-binding lectin genetics: from A to Z

DEFF Research Database (Denmark)

Garred, Peter

2008-01-01

MBL (mannose-binding lectin) is primarily a liver-derived collagen-like serum protein. It binds sugar structures on micro-organisms and on dying host cells and is one of the four known mediators that initiate activation of the complement system via the lectin pathway. Common variant alleles situa...

Developmental changes in cytosolic coupling between epidermis cells as visualized by photoactivation of fluorescein

DEFF Research Database (Denmark)

Liu, Xiangdong; Martens, Helle; Schulz, Alexander

Developmental changes in cytosolic coupling between epidermis cells as visualized by photoactivation of fluorescein.......Developmental changes in cytosolic coupling between epidermis cells as visualized by photoactivation of fluorescein....

Lectin-based food poisoning: a new mechanism of protein toxicity.

Science.gov (United States)

Miyake, Katsuya; Tanaka, Toru; McNeil, Paul L

2007-08-01

Ingestion of the lectins present in certain improperly cooked vegetables can result in acute GI tract distress, but the mechanism of toxicity is unknown. In vivo, gut epithelial cells are constantly exposed to mechanical and other stresses and consequently individual cells frequently experience plasma membrane disruptions. Repair of these cell surface disruptions allows the wounded cell to survive: failure results in necrotic cell death. Plasma membrane repair is mediated, in part, by an exocytotic event that adds a patch of internal membrane to the defect site. Lectins are known to inhibit exocytosis. We therefore tested the novel hypothesis that lectin toxicity is due to an inhibitory effect on plasma membrane repair. Repair of plasma membrane disruptions and exocytosis of mucus was assessed after treatment of cultured cell models and excised segments of the GI tract with lectins. Plasma membrane disruptions were produced by focal irradiation of individual cells, using a microscope-based laser, or by mechanical abrasion of multiple cells, using a syringe needle. Repair was then assessed by monitoring the cytosolic penetration of dyes incapable of crossing the intact plasma membrane. We found that cell surface-bound lectins potently inhibited plasma membrane repair, and the exocytosis of mucus that normally accompanies the repair response. Lectins potently inhibit plasma membrane repair, and hence are toxic to wounded cells. This represents a novel form of protein-based toxicity, one that, we propose, is the basis of plant lectin food poisoning.

Lectin-based food poisoning: a new mechanism of protein toxicity.

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Katsuya Miyake

Full Text Available BACKGROUND: Ingestion of the lectins present in certain improperly cooked vegetables can result in acute GI tract distress, but the mechanism of toxicity is unknown. In vivo, gut epithelial cells are constantly exposed to mechanical and other stresses and consequently individual cells frequently experience plasma membrane disruptions. Repair of these cell surface disruptions allows the wounded cell to survive: failure results in necrotic cell death. Plasma membrane repair is mediated, in part, by an exocytotic event that adds a patch of internal membrane to the defect site. Lectins are known to inhibit exocytosis. We therefore tested the novel hypothesis that lectin toxicity is due to an inhibitory effect on plasma membrane repair. METHODS AND FINDINGS: Repair of plasma membrane disruptions and exocytosis of mucus was assessed after treatment of cultured cell models and excised segments of the GI tract with lectins. Plasma membrane disruptions were produced by focal irradiation of individual cells, using a microscope-based laser, or by mechanical abrasion of multiple cells, using a syringe needle. Repair was then assessed by monitoring the cytosolic penetration of dyes incapable of crossing the intact plasma membrane. We found that cell surface-bound lectins potently inhibited plasma membrane repair, and the exocytosis of mucus that normally accompanies the repair response. CONCLUSIONS: Lectins potently inhibit plasma membrane repair, and hence are toxic to wounded cells. This represents a novel form of protein-based toxicity, one that, we propose, is the basis of plant lectin food poisoning.

Immunotoxicological studies of genetically modified rice expressing PHA-E lectin or Bt toxin in Wistar rats

International Nuclear Information System (INIS)

Kroghsbo, Stine; Madsen, Charlotte; Poulsen, Morten; Schroder, Malene; Kvist, Peter H.; Taylor, Mark; Gatehouse, Angharad; Shu, Qingyao; Knudsen, Ib

2008-01-01

As part of the SAFOTEST project the immunmodulating effect of Cry1Ab protein from Bacillus thuringiensis (Bt) and PHA-E lectin from kidney bean (Phaseolus vulgaris erythroagglutinin) was examined in 28- and 90-day feeding studies in Wistar rats. PHA-E lectin was chosen as positive control. Rats were fed control rice, transgenic rice expressing Cry1Ab protein or PHA-E lectin, or transgenic rice spiked with the purified recombinant protein. Total immunoglobulin levels, mitogen-induced cell proliferation, T-dependent antibody response to sheep red blood cells and the antigen-specific antibody response in serum were examined at the end of the studies. A dose-dependent increase in mesenteric lymph node weight and total immunoglobulin A was seen when feeding PHA-E transgenic rice alone or spiked with 0.1% purified PHA-E lectin for 90 days indicating a local effect of PHA-E in the intestine. No adverse effects of Cry1Ab protein were found. An anti-PHA-E and anti-Cry1Ab antibody response was induced both after inhalation (control groups) and after inhalation/ingestion (groups fed recombinant protein alone or together with transgenic rice). In conclusion, only PHA-E lectin was found to have an immunomodulating effect when feeding rats for 90 days with approximately 70 mg PHA-E/kg bodyweight per day. As both PHA-E lectin and Cry1Ab protein were capable of inducing an antigen-specific antibody response it is important to make careful considerations when designing future animal studies to avoid intake of proteins from the other groups by inhalation as well as to examine the sensitization and elicitation potential of 'foreign' proteins before introduction to the world market

Raman spectroscopy in investigations of mechanism of binding of human serum albumin to molecular probe fluorescein

International Nuclear Information System (INIS)

Vlasova, I M; Saletsky, A M

2008-01-01

The mechanism of binding of molecular probe fluorescein to molecules of human serum albumin was studied by the Raman spectroscopy method. The position of binding Center on human serum albumin molecule for fluorescein is determined. The amino acid residues of albumin molecule, participating in binding of fluorescein at different pH values of solution, are established. The conformation rearrangements of globules of human serum albumin, taking place at binding of fluorescein at different pH values of solution, are registered

Unfolding energetics and stability of banana lectin.

Science.gov (United States)

Gupta, Garima; Sinha, Sharmistha; Surolia, Avadhesha

2008-08-01

The unfolding pathway of banana lectin from Musa paradisiaca was determined by isothermal denaturation induced by the chaotrope GdnCl. The unfolding was found to be a reversible process. The data obtained by isothermal denaturation provided information on conformational stability of banana lectin. The high values of DeltaG of unfolding at various temperatures indicated the strength of intersubunit interactions. It was found that banana lectin is a very stable and denatures at high chaotrope concentrations only. The basis of the stability may be attributed to strong hydrogen bonds of the order 2.5-3.1 A at the dimeric interface along with the presence of water bridges. This is perhaps very unique example in proteins where subunit association is not a consequence of the predominance of hydrophobic interactions. (c) 2008 Wiley-Liss, Inc.

Glycoproteins of axonal transport: affinity chromatography on fucose-specific lectins

Energy Technology Data Exchange (ETDEWEB)

Gustavsson, S.; Ohlson, C.; Karlsson, J.O.

1982-03-01

Rapidly transported fucose-labeled glycoproteins from axons of rabbit retinal ganglion cells were solubilized with nonionic detergents. The solubilized components were subjected to affinity chromatography on three different fucose-specific lectins. A recently characterized fucose-specific lectin from Aleuria aurantia bound reversibly approximately 60% of the applied protein-bound radioactivity. The lectins from Lotus tetragonolobus and Ulex europaeus bound are very small proportions of the labeled rapidly transported glycoproteins.

Interaction of lectins with membrane receptors on erythrocyte surfaces.

Science.gov (United States)

Sung, L A; Kabat, E A; Chien, S

1985-08-01

The interactions of human genotype AO erythrocytes (red blood cells) (RBCs) with N-acetylgalactosamine-reactive lectins isolated from Helix pomatia (HPA) and from Dolichos biflorus (DBA) were studied. Binding curves obtained with the use of tritium-labeled lectins showed that the maximal numbers of lectin molecules capable of binding to human genotype AO RBCs were 3.8 X 10(5) and 2.7 X 10(5) molecules/RBC for HPA and DBA, respectively. The binding of one type of lectin may influence the binding of another type. HPA was found to inhibit the binding of DBA, but not vice versa. The binding of HPA was weakly inhibited by a beta-D-galactose-reactive lectin isolated from Ricinus communis (designated RCA1). Limulus polyphemus lectin (LPA), with specificity for N-acetylneuraminic acid, did not influence the binding of HPA but enhanced the binding of DBA. About 80% of LPA receptors (N-acetylneuraminic acid) were removed from RBC surfaces by neuraminidase treatment. Neuraminidase treatment of RBCs resulted in increases of binding of both HPA and DBA, but through different mechanisms. An equal number (7.6 X 10(5) of new HPA sites were generated on genotypes AO and OO RBCs by neuraminidase treatment, and these new sites accounted for the enhancement (AO cells) and appearance (OO cells) of hemagglutinability by HPA. Neuraminidase treatment did not generate new DBA sites, but increased the DBA affinity for the existing receptors; as a result, genotype AO cells increased their hemagglutinability by DBA, while OO cells remained unagglutinable. The use of RBCs of different genotypes in binding assays with 3H-labeled lectins of known specificities provides an experimental system for studying cell-cell recognition and association.

Lectin typing of Campylobacter jejuni using a novel quartz crystal microbalance technique

Energy Technology Data Exchange (ETDEWEB)

Yakovleva, Maria E., E-mail: maria.yakovleva@gmail.com [Department of Infectious Diseases and Medical Microbiology, Lund University, 223 62 Lund (Sweden); Moran, Anthony P. [Department of Microbiology, School of Natural Sciences, National University of Ireland, Galway (Ireland); Safina, Gulnara R. [Department of Analytical and Marine Chemistry, University of Gothenburg, 412 96 Gothenburg (Sweden); Wadstroem, Torkel [Department of Infectious Diseases and Medical Microbiology, Lund University, 223 62 Lund (Sweden); Danielsson, Bengt [Acromed Invest AB, Magistratsvaegen 10, 226 43 Lund (Sweden)

2011-05-23

Seven Campylobacter jejuni strains were characterised by a lectin typing assay. The typing system was based on a quartz crystal microbalance technique (QCM) with four commercially available lectins (wheat germ agglutinin, Maackia amurensis lectin, Lens culinaris agglutinin, and Concanavalin A), which were chosen for their differing carbohydrate specificities. Initially, the gold surfaces of the quartz crystals were modified with 11-mercaptoundecanoic acid followed by lectin immobilisation using a conventional amine-coupling technique. Bacterial cells were applied for lectin typing without preliminary treatment, and resonant frequency and dissipation responses were recorded. The adhesion of microorganisms on lectin surfaces was confirmed by atomic force microscopy. Scanning was performed in the tapping mode and the presence of bacteria on lectin-coated surfaces was successfully demonstrated. A significant difference in the dissipation response was observed for different C. jejuni strains which made it possible to use this parameter for discriminating between bacterial strains. In summary, the QCM technique proved a powerful tool for the recognition and discrimination of C. jejuni strains. The approach may also prove applicable to strain discrimination of other bacterial species, particularly pathogens.

Lectin typing of Campylobacter jejuni using a novel quartz crystal microbalance technique

International Nuclear Information System (INIS)

Yakovleva, Maria E.; Moran, Anthony P.; Safina, Gulnara R.; Wadstroem, Torkel; Danielsson, Bengt

2011-01-01

Seven Campylobacter jejuni strains were characterised by a lectin typing assay. The typing system was based on a quartz crystal microbalance technique (QCM) with four commercially available lectins (wheat germ agglutinin, Maackia amurensis lectin, Lens culinaris agglutinin, and Concanavalin A), which were chosen for their differing carbohydrate specificities. Initially, the gold surfaces of the quartz crystals were modified with 11-mercaptoundecanoic acid followed by lectin immobilisation using a conventional amine-coupling technique. Bacterial cells were applied for lectin typing without preliminary treatment, and resonant frequency and dissipation responses were recorded. The adhesion of microorganisms on lectin surfaces was confirmed by atomic force microscopy. Scanning was performed in the tapping mode and the presence of bacteria on lectin-coated surfaces was successfully demonstrated. A significant difference in the dissipation response was observed for different C. jejuni strains which made it possible to use this parameter for discriminating between bacterial strains. In summary, the QCM technique proved a powerful tool for the recognition and discrimination of C. jejuni strains. The approach may also prove applicable to strain discrimination of other bacterial species, particularly pathogens.

Effect of Lectins from Diocleinae Subtribe against Oral Streptococci

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Edson Holanda Teixeira

2011-04-01

Full Text Available Surface colonization is an essential step in biofilm development. The ability of oral pathogens to adhere to tooth surfaces is directly linked with the presence of specific molecules at the bacterial surface that can interact with enamel acquired pellicle ligands. In light of this, the aim of this study was to verify inhibitory and antibiofilm action of lectins from the Diocleinaesubtribe against Streptococcus mutans and Streptococcus oralis. The inhibitory action against planctonic cells was assessed using lectins from Canavaliaensi formis (ConA, Canavalia brasiliensis (ConBr, Canavalia maritima (ConM, Canavalia gladiata (CGL and Canavalia boliviana (ConBol. ConBol, ConBr and ConM showed inhibitory activity on S. mutans growth. All lectins, except ConA, stimulated significantly the growth of S. oralis. To evaluate the effect on biofilm formation, clarified saliva was added to 96-well, flat-bottomed polystyrene plates, followed by the addition of solutions containing 100 or 200 µg/mL of the selected lectins. ConBol, ConM and ConA inhibited the S. mutans biofilms. No effects were found on S. oralis biofilms. Structure/function analysis were carried out using bioinformatics tools. The aperture and deepness of the CRD (Carbohydrate Recognition Domain permit us to distinguish the two groups of Canavalia lectins in accordance to their actions against S. mutans and S. oralis. The results found provide a basis for encouraging the use of plant lectins as biotechnological tools in ecological control and prevention of caries disease.

Plant lectins: the ties that bind in root symbiosis and plant defense.

Science.gov (United States)

De Hoff, Peter L; Brill, Laurence M; Hirsch, Ann M

2009-07-01

Lectins are a diverse group of carbohydrate-binding proteins that are found within and associated with organisms from all kingdoms of life. Several different classes of plant lectins serve a diverse array of functions. The most prominent of these include participation in plant defense against predators and pathogens and involvement in symbiotic interactions between host plants and symbiotic microbes, including mycorrhizal fungi and nitrogen-fixing rhizobia. Extensive biological, biochemical, and molecular studies have shed light on the functions of plant lectins, and a plethora of uncharacterized lectin genes are being revealed at the genomic scale, suggesting unexplored and novel diversity in plant lectin structure and function. Integration of the results from these different types of research is beginning to yield a more detailed understanding of the function of lectins in symbiosis, defense, and plant biology in general.

Effect of Betong Watercress and Phenethyl Isothiocyanate on N ...

African Journals Online (AJOL)

Purpose: To investigate the effect of Betong watercress and phenethyl isothiocyanate (PEITC) on the N-demethylation of caffeine (CF) in rats. Methods: Male Wistar rats were subjected to 2 phases of experiment. Phase I, they received a single oral dose of CF (10 mg/kg), while in phase II, they were pretreated with the ...

Microbial- and isothiocyanate-mediated control of Phytophthora and Pythium species

Science.gov (United States)

M.F. Cohen; E. Yamamoto; E. Condeso; B.L. Anacker; N. Rank; M. Mazzola

2008-01-01

Plant pathogens of the oomycete lineage share common susceptibilities to many biotic and abiotic stresses. We are investigating the potential of antagonistic bacteria, isothiocyanates, and mycophagous amoebae to control diseases caused by Phytophthora spp., including the etiologic agent of sudden oak death, Phytophthora ramorum (...

Biochemical characterization and anti-inflammatory properties of an isothiocyanate-enriched moringa (Moringa oleifera) seed extract.

Science.gov (United States)

Jaja-Chimedza, Asha; Graf, Brittany L; Simmler, Charlotte; Kim, Youjin; Kuhn, Peter; Pauli, Guido F; Raskin, Ilya

2017-01-01

Moringa oleifera Lam. is a tropical plant, used for centuries as food and traditional medicine. The aim of this study was to develop, validate and biochemically characterize an isothiocyanate-enriched moringa seed extract (MSE), and to compare the anti-inflammatory effects of MSE-containing moringa isothiocyanate-1 (MIC-1) with a curcuminoid-enriched turmeric extract (CTE), and a material further enriched in its primary phytochemical, curcumin (curcumin-enriched material; CEM). MSE was prepared by incubating ground moringa seeds with water to allow myrosinase-catalyzed enzymatic formation of bioactive MIC-1, the predominant isothiocyanate in moringa seeds. Optimization of the extraction process yielded an extract of 38.9% MIC-1. Phytochemical analysis of MSE revealed the presence of acetylated isothiocyanates, phenolic glycosides unique to moringa, flavonoids, fats and fatty acids, proteins and carbohydrates. MSE showed a reduction in the carrageenan-induced rat paw edema (33% at 500 mg/kg MIC-1) comparable to aspirin (27% at 300 mg/kg), whereas CTE did not have any significant effect. In vitro, MIC-1 at 1 μM significantly reduced the production of nitric oxide (NO) and at 5 μM, the gene expression of LPS-inducible nitric oxide synthase (iNOS) and interleukins 1β and 6 (IL-1β and IL-6), whereas CEM did not show any significant activity at all concentrations tested. MIC-1 (10μM) was also more effective at upregulating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) target genes NAD(P)H:quinone oxidoreductase 1 (NQO1), glutathione S-transferase pi 1 (GSTP1), and heme oxygenase 1 (HO1) than the CEM. Thus, in contrast to CTE and CEM, MSE and its major isothiocyanate MIC-1 displayed strong anti-inflammatory and antioxidant properties in vivo and in vitro, making them promising botanical leads for the mitigation of inflammatory-mediated chronic disorders.

Biochemical characterization and anti-inflammatory properties of an isothiocyanate-enriched moringa (Moringa oleifera seed extract.

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Asha Jaja-Chimedza

Full Text Available Moringa oleifera Lam. is a tropical plant, used for centuries as food and traditional medicine. The aim of this study was to develop, validate and biochemically characterize an isothiocyanate-enriched moringa seed extract (MSE, and to compare the anti-inflammatory effects of MSE-containing moringa isothiocyanate-1 (MIC-1 with a curcuminoid-enriched turmeric extract (CTE, and a material further enriched in its primary phytochemical, curcumin (curcumin-enriched material; CEM. MSE was prepared by incubating ground moringa seeds with water to allow myrosinase-catalyzed enzymatic formation of bioactive MIC-1, the predominant isothiocyanate in moringa seeds. Optimization of the extraction process yielded an extract of 38.9% MIC-1. Phytochemical analysis of MSE revealed the presence of acetylated isothiocyanates, phenolic glycosides unique to moringa, flavonoids, fats and fatty acids, proteins and carbohydrates. MSE showed a reduction in the carrageenan-induced rat paw edema (33% at 500 mg/kg MIC-1 comparable to aspirin (27% at 300 mg/kg, whereas CTE did not have any significant effect. In vitro, MIC-1 at 1 μM significantly reduced the production of nitric oxide (NO and at 5 μM, the gene expression of LPS-inducible nitric oxide synthase (iNOS and interleukins 1β and 6 (IL-1β and IL-6, whereas CEM did not show any significant activity at all concentrations tested. MIC-1 (10μM was also more effective at upregulating the nuclear factor (erythroid-derived 2-like 2 (Nrf2 target genes NAD(PH:quinone oxidoreductase 1 (NQO1, glutathione S-transferase pi 1 (GSTP1, and heme oxygenase 1 (HO1 than the CEM. Thus, in contrast to CTE and CEM, MSE and its major isothiocyanate MIC-1 displayed strong anti-inflammatory and antioxidant properties in vivo and in vitro, making them promising botanical leads for the mitigation of inflammatory-mediated chronic disorders.

New perspectives on mannan-binding lectin-mediated complement activation

DEFF Research Database (Denmark)

Degn, Søren Egedal; Thiel, Steffen; Jensenius, Jens Christian

2007-01-01

The complement system is an important part of the innate immune system, mediating several major effector functions and modulating adaptive immune responses. Three complement activation pathways exist: the classical pathway (CP), the alternative pathway (AP), and the lectin pathway (LP). The LP......, allowing C3 activation in the absence of components otherwise believed critical. The classical bypass pathways are dependent on C1 and components of the AP. A recent study has shown the existence also of a lectin bypass pathway dependent on mannan-binding lectin (MBL) and AP components. The emerging...

Detection, purification and characterization of a lectin from freshwater green algae Spirogyra spp.

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ANTÔNIA S. DE OLIVEIRA

2017-08-01

Full Text Available ABSTRACT Freshwater algae are rich sources of structurally biologically active metabolites, such as fatty acids, steroids, carotenoids and polysaccharides. Among these metabolites, lectins stand out. Lectins are proteins or glycoproteins of non-immune origin which bind to carbohydrates or glycoconjugates, without changing ligand structure. Many studies have reported on the use of Spirogyra spp. as effective bioindicators of heavy metals; however, reports on Spirogyra molecular bioprospecting are quite limited. Therefore, this study aimed to detect, isolate, purify and characterize a lectin present in the freshwater green algae Spirogyra. Presence of the lectin protein in the extract was detected by hemagglutination assays. Subsequently, the protein extract was subjected to a sugar inhibition assay to identify the lectin-specific carbohydrate. Following this, the extract was applied to a guar gum column to afford the pure lectin. The lectin was inhibited by N-acetyl-glucosamine and N-acetyl-beta-D-mannose, but more strongly by D-galactose. The apparent molecular mass of the purified lectin was evaluated by Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE. Electrophoretic analysis revealed a single protein band with an apparent molecular mass of 56 kDa. Thus, it could be concluded that a lectin was purified from Spirogyra spp.

Fluorescein angiography and retinal vascular development in premature infants.

Science.gov (United States)

Purcaro, Velia; Velia, Purcaro; Baldascino, Antonio; Antonio, Baldascino; Papacci, Patrizia; Patrizia, Papacci; Giannantonio, Carmen; Carmen, Giannantonio; Molisso, Anna; Anna, Molisso; Molle, Fernando; Fernando, Molle; Lepore, Domenico; Domenico, Lepore; Romagnoli, Costantino; Costantino, Romagnoli

2012-10-01

To investigate the role of fluorescein angiography (FA) in the management of retinopathy of prematurity (ROP) in preterm newborns. An observational case series of 13 extremely low birth weight infants. From September 2009 to March 2010, 13 newborn infants with a gestational age <29 weeks end/or birth weight <1000 g underwent serial fluorescein angiography with RetCam (Clarity, Pleasanton, CA) every 2 weeks. The fluorescein angiograms were examined to optimize the timing of diagnosis of ROP and to investigate development of retinal and choroidal vascularization. There were no side effects related to FA. Variable features of retinal and choroidal circulation in preterm infants with a high risk of developing ROP were noted. FA allows vessels branching at the junction between vascular and avascular retina (V-Av junction) to be viewed easily and shows the ROP findings that sometimes cannot be seen by indirect ophthalmoscopy. Dye leakage is the most significant sign of progression to severe ROP or the need for surgery in newborn babies with ROP. RetCam-assisted intravenous FA is safe and allows a more objective assessment of the ROP stage and zone.

Development of novel radiosensitizers for cancer therapy

CERN Document Server

Akamatsu, K

2002-01-01

The novel radiosensitizers for cancer therapy, which have some atoms with large X-ray absorption cross sections, were synthesized. The chemical and radiation (X-rays, W target, 100kVp) toxicities and the radiosensitivities to LS-180 human colon adenocarcinoma cells were also evaluated. 2,3,4,5,6-pentabromobenzylalcohol (PBBA) derivatives were not radiosensitive even around the maximum concentration. On the other hand, the hydrophilic sodium 2,4,6-triiodobenzoate (STIB) indicated meaningful radiosensitivity to the cells. Moreover, the membrane-specific radiosensitizers, cetyl fluorescein isthiocyanate (cetyl FITC), cetyl eosin isothiocyanate (cetyl br-FITC), cetyl erythrosin isothiocyanate (cetyl I-FITC), which aim for the membrane damage by X-ray photoabsorption on the target atoms, were localized in the plasma membrane. As the results of the colony formation assay, it was found that both cetyl FITC are similarly radiosensitive. In this report, we demonstrate the synthetic methods of the radiosensitizers, the...

Electronic Detection of Lectins Using Carbohydrate Functionalized Nanostructures: Graphene versus Carbon Nanotubes

Science.gov (United States)

Chen, Yanan; Vedala, Harindra; Kotchey, Gregg P.; Audfray, Aymeric; Cecioni, Samy; Imberty, Anne; Vidal, Sébastien; Star, Alexander

2012-01-01

Here we investigated the interactions between lectins and carbohydrates using field-effect transistor (FET) devices comprised of chemically converted graphene (CCG) and single-walled carbon nanotubes (SWNTs). Pyrene- and porphyrin-based glycoconjugates were functionalized noncovalently on the surface of CCG-FET and SWNT-FET devices, which were then treated with 2 µM of nonspecific and specific lectins. In particular, three different lectins (PA-IL, PA-IIL and ConA) and three carbohydrate epitopes (galactose, fucose and mannose) were tested. The responses of 36 different devices were compared and rationalized using computer-aided models of carbon nanostructure/glycoconjugate interactions. Glycoconjugates surface coverage in addition to one-dimensional structures of SWNTs resulted in optimal lectin detection. Additionally, lectin titration data of SWNT- and CCG-based biosensors were used to calculate lectin dissociation constants (Kd) and compare them to the values obtained from the isothermal titration microcalorimetry (ITC) technique. PMID:22136380

Evolutionary history and stress regulation of the lectin superfamily in higher plants

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Ramachandran Srinivasan

2010-03-01

Full Text Available Abstract Background Lectins are a class of carbohydrate-binding proteins. They play roles in various biological processes. However, little is known about their evolutionary history and their functions in plant stress regulation. The availability of full genome sequences from various plant species makes it possible to perform a whole-genome exploration for further understanding their biological functions. Results Higher plant genomes encode large numbers of lectin proteins. Based on their domain structures and phylogenetic analyses, a new classification system has been proposed. In this system, 12 different families have been classified and four of them consist of recently identified plant lectin members. Further analyses show that some of lectin families exhibit species-specific expansion and rapid birth-and-death evolution. Tandem and segmental duplications have been regarded as the major mechanisms to drive lectin expansion although retrogenes also significantly contributed to the birth of new lectin genes in soybean and rice. Evidence shows that lectin genes have been involved in biotic/abiotic stress regulations and tandem/segmental duplications may be regarded as drivers for plants to adapt various environmental stresses through duplication followed by expression divergence. Each member of this gene superfamily may play specialized roles in a specific stress condition and function as a regulator of various environmental factors such as cold, drought and high salinity as well as biotic stresses. Conclusions Our studies provide a new outline of the plant lectin gene superfamily and advance the understanding of plant lectin genes in lineage-specific expansion and their functions in biotic/abiotic stress-related developmental processes.

Differential activity of a lectin from Solieria filiformis against human pathogenic bacteria

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M.L. Holanda

2005-12-01

Full Text Available A lectin isolated from the red alga Solieria filiformis was evaluated for its effect on the growth of 8 gram-negative and 3 gram-positive bacteria cultivated in liquid medium (three independent experiments/bacterium. The lectin (500 µg/mL stimulated the growth of the gram-positive species Bacillus cereus and inhibited the growth of the gram-negative species Serratia marcescens, Salmonella typhi, Klebsiella pneumoniae, Enterobacter aerogenes, Proteus sp, and Pseudomonas aeruginosa at 1000 µg/mL but the lectin (10-1000 µg/mL had no effect on the growth of the gram-positive bacteria Staphylococcus aureus and B. subtilis, or on the gram-negative bacteria Escherichia coli and Salmonella typhimurium. The purified lectin significantly reduced the cell density of gram-negative bacteria, although no changes in growth phases (log, exponential and of decline were observed. It is possible that the interaction of S. filiformis lectin with the cell surface receptors of gram-negative bacteria promotes alterations in the flow of nutrients, which would explain the bacteriostatic effect. Growth stimulation of the gram-positive bacterium B. cereus was more marked in the presence of the lectin at a concentration of 1000 µg/mL. The stimulation of the growth of B. cereus was not observed when the lectin was previously incubated with mannan (125 µg/mL, its hapten. Thus, we suggest the involvement of the binding site of the lectin in this effect. The present study reports the first data on the inhibition and stimulation of pathogenic bacterial cells by marine alga lectins.

PO-20 - Crosstalk between the lectin pathway and haemostasis in patients with pulmonary cancer

DEFF Research Database (Denmark)

Larsen, J B; Christensen, T D; Hvas, C L

2016-01-01

INTRODUCTION: Recent research has focused on the complement system in cancer, including the lectin pathway of complement activation. Mannose-binding lectin (MBL), a key activator of the lectin pathway, can bind to tumor cell surfaces in vitro, and lectin pathway activation is increased in several...

Small unilamellar vesicles as reagents: a chemically defined, quantitative assay for lectins

Energy Technology Data Exchange (ETDEWEB)

Rando, R.R.

1981-01-01

Samll unilamellar vesicles containing synthetic glycolipids can be prepared. These vesicles are aggregated by the appropriate lectin (Orr et al., 1979; Rando and Bangerter, 1979; Slama and Rando, 1980). It is shown here that extent of aggregation of these vesicles as measured by light scattering at 360 nm, is, under certain conditions, linear with amount of lectin added. This forms the basis of a rapid and simple quantitative assay for lectins using the modified vesicles as a defined chemical substrate. The assay is sensitive to lectin concentrations in the low ..mu..g range. The assay is applied here to studies on concanavalin A, Ricinus communis agglutinin and the ..cap alpha..-fucosyl binding lectin from Ulex europaeus (Type I).

Fluorescein-labeled stable neurotensin derivatives.

Science.gov (United States)

Maes, Veronique; Hultsch, Christina; Kohl, Suzann; Bergmann, Ralf; Hanke, Thomas; Tourwé, Dirk

2006-08-01

Neurotensin(8-13) analogs containing a glycine or 5-aminovaleroyl spacer were labeled with fluorescein through formation of an N-terminal thiourea function. The receptor binding was measured in HT-29 cell cultures and showed a substantial decrease in affinity, especially for the metabolically stabilized [MeArg(9), Tle(11)] analog. Using fluorescence microscopy, the internalization of the fluorescent neurotensin analogs into HT-29 cells was observed. Copyright (c) 2006 European Peptide Society and John Wiley & Sons, Ltd.

Rachycentron canadum (cobia) lectin promoted mitogenic response in mice BALB/c splenocytes.

Science.gov (United States)

Coriolano, M C; de Melo, C M L; Santos, A J G; Pereira, V R A; Coelho, L C B B

2012-12-01

The mitogenic lectins are invaluable tools to study the biochemical changes associated with lymphocyte activation and proliferation of various immune cells. Rachycentron canadum lectin (RcaL) was detected and purified from serum of cobia fish. The aim of this study was to evaluate the proliferative response and cytokine production in splenocytes of mice in vitro stimulated with RcaL lectin; Canavalia ensiformis lectin (Con A) was used as positive control. A high proliferation index was induced by RcaL in relation to control cells. Furthermore, RcaL induced higher IL-2 and IL-6 production in relation to control. The cell viability was 90% in splenocytes treated with RcaL lectin, but RcaL promoted significant late apoptosis after 24 and 48 h in relation to control. RcaL induced proliferative responses suggesting that this lectin can be used as a mitogenic agent in immunostimulatory assays. © 2012 The Authors. Scandinavian Journal of Immunology © 2012 Blackwell Publishing Ltd.

A C-Type Lectin from Bothrops jararacussu Venom Disrupts Staphylococcal Biofilms

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Klein, Raphael Contelli; Fabres-Klein, Mary Hellen; de Oliveira, Leandro Licursi; Feio, Renato Neves; Malouin, François; Ribon, Andréa de Oliveira Barros

2015-01-01

Bovine mastitis is a major threat to animal health and the dairy industry. Staphylococcus aureus is a contagious pathogen that is usually associated with persistent intramammary infections, and biofilm formation is a relevant aspect of the outcome of these infections. Several biological activities have been described for snake venoms, which led us to screen secretions of Bothrops jararacussu for antibiofilm activity against S. aureus NRS155. Crude venom was fractionated by size-exclusion chromatography, and the fractions were tested against S. aureus. Biofilm growth, but not bacterial growth, was affected by several fractions. Two fractions (15 and 16) showed the best activities and were also assayed against S. epidermidis NRS101. Fraction 15 was identified by TripleTOF mass spectrometry as a galactose-binding C-type lectin with a molecular weight of 15 kDa. The lectin was purified from the crude venom by D-galactose affinity chromatography, and only one peak was observed. This pure lectin was able to inhibit 75% and 80% of S. aureus and S. epidermidis biofilms, respectively, without affecting bacterial cell viability. The lectin also exhibited a dose-dependent inhibitory effect on both bacterial biofilms. The antibiofilm activity was confirmed using scanning electron microscopy. A pre-formed S. epidermidis biofilm was significantly disrupted by the C-type lectin in a time-dependent manner. Additionally, the lectin demonstrated the ability to inhibit biofilm formation by several mastitis pathogens, including different field strains of S. aureus, S. hyicus, S. chromogenes, Streptococcus agalactiae, and Escherichia coli. These findings reveal a new activity for C-type lectins. Studies are underway to evaluate the biological activity of these lectins in a mouse mastitis model. PMID:25811661

A C-type lectin from Bothrops jararacussu venom disrupts Staphylococcal biofilms.

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Raphael Contelli Klein

Full Text Available Bovine mastitis is a major threat to animal health and the dairy industry. Staphylococcus aureus is a contagious pathogen that is usually associated with persistent intramammary infections, and biofilm formation is a relevant aspect of the outcome of these infections. Several biological activities have been described for snake venoms, which led us to screen secretions of Bothrops jararacussu for antibiofilm activity against S. aureus NRS155. Crude venom was fractionated by size-exclusion chromatography, and the fractions were tested against S. aureus. Biofilm growth, but not bacterial growth, was affected by several fractions. Two fractions (15 and 16 showed the best activities and were also assayed against S. epidermidis NRS101. Fraction 15 was identified by TripleTOF mass spectrometry as a galactose-binding C-type lectin with a molecular weight of 15 kDa. The lectin was purified from the crude venom by D-galactose affinity chromatography, and only one peak was observed. This pure lectin was able to inhibit 75% and 80% of S. aureus and S. epidermidis biofilms, respectively, without affecting bacterial cell viability. The lectin also exhibited a dose-dependent inhibitory effect on both bacterial biofilms. The antibiofilm activity was confirmed using scanning electron microscopy. A pre-formed S. epidermidis biofilm was significantly disrupted by the C-type lectin in a time-dependent manner. Additionally, the lectin demonstrated the ability to inhibit biofilm formation by several mastitis pathogens, including different field strains of S. aureus, S. hyicus, S. chromogenes, Streptococcus agalactiae, and Escherichia coli. These findings reveal a new activity for C-type lectins. Studies are underway to evaluate the biological activity of these lectins in a mouse mastitis model.

Protozoa lectins and their role in host-pathogen interactions.

Science.gov (United States)

Singh, Ram Sarup; Walia, Amandeep Kaur; Kanwar, Jagat Rakesh

2016-01-01

Lectins are proteins/glycoproteins of non-immune origin that agglutinate red blood cells, lymphocytes, fibroblasts, etc., and bind reversibly to carbohydrates present on the apposing cells. They have at least two carbohydrate binding sites and their binding can be inhibited by one or more carbohydrates. Owing to carbohydrate binding specificity of lectins, they mediate cell-cell interactions and play role in protozoan adhesion and host cell cytotoxicity, thus are central to the pathogenic property of the parasite. Several parasitic protozoa possess lectins which mediate parasite adherence to host cells based on their carbohydrate specificities. These interactions could be exploited for development of novel therapeutics, targeting the adherence and thus helpful in eradicating wide spread of protozoan diseases. The current review highlights the present state knowledge with regard to protozoal lectins with an emphasis on their haemagglutination activity, carbohydrate specificity, characteristics and also their role in pathogenesis notably as adhesion molecules, thereby aiding the pathogen in disease establishment. Copyright © 2016 Elsevier Inc. All rights reserved.

A comparative immunohistochemical study on amylase localization in the rat and human exocrine pancreas

International Nuclear Information System (INIS)

Aughsteen, Adib A.

2001-01-01

Objective was to localize amylase enzyme immunohistochemically in the pancreatic acinar cells of rats and humans using polyclonal sheep anti-human amylase antibody, and to compare between the intensities of their amylase-immunostaining. Indirect immunofluorescence method was applied on formaldehyde-fixed, and paraffin-embedded pancreatic sections obtained from adult male Wistar rats and autopsied human samples. Primary incubation was performed using sheep anti-amylase antibody followed by secondary incubation with fluorescein isothiocyanate-labeled rabbit anti-sheep IgG serum. Control tests of amylase immunospecificity were also undertaken either by incubation with primary antibodies previously pre-adsorbed with an excess of human pancreatic amylase, or only with secondary antibodies. The amylase immunofluorescence was positively and homogenously detected in all acinar cells of both rat and human pancreatic stained sections. The immunostaining was clearly demonstrated in the cell apices and peri-nuclear areas, but it was consistently brighter and more intense in the human acinar cells compared with that of the rat pancreas. Control tests of amylase immunofluorescence revealed the specificity of the antibodies applied for amylase localization in rat and human pancreas. Although many previous immunohisto- and cytochemical reports have successfully localized amylase in the pancreas of different mammalian species, but all of them have used locally prepared anti-amylase antibodies. The present report successfully illustrates immuno-localization of amylase in the pancreatic acinar cells of rats and humans using commercial polyclonal sheep anti-human pancreatic amylase antibodies, and also suggests their useful application in the immunochemical studies on various mammalian species. Additionally, the results indicate a structural similarity between the human and rat pancreatic amylases, a concept required further exploration. (author)

Collectin-11/MASP complex formation triggers activation of the lectin complement pathway--the fifth lectin pathway initiation complex

DEFF Research Database (Denmark)

Ma, Ying Jie; Skjoedt, Mikkel-Ole; Garred, Peter

2013-01-01

Collectins and ficolins are important in the clearance of endogenous and exogenous danger materials. A new human collectin-11 was recently identified in low concentration in serum in complex with mannose-binding lectin (MBL)/ficolin-associated serine proteases. Collectin-11 binds to carbohydrate...... complement complex on C. albicans. Moreover, spiking collectin-11-depleted serum, which did not mediate complement activation, with recombinant collectin-11 restored the complement activation capability. These results define collectin-11 as the fifth recognition molecule in the lectin complement pathway...

Activation of the lectin complement pathway on human renal ...

African Journals Online (AJOL)

This study aimed to investigate the roles of high glucose and mannose-binding lectin (MBL) on the activation of the lectin complement pathway (LCP) on human renal glomerular endothelial cells (HRGECs) in vitro. Flow cytometry analysis, immunofluorescence staining and Western blot were used to detect the cell surface ...

Stability of Curcuma longa rhizome lectin: Role of N-linked glycosylation.

Science.gov (United States)

Biswas, Himadri; Chattopadhyaya, Rajagopal

2016-04-01

Curcuma longa rhizome lectin, a mannose-binding protein of non-seed portions of turmeric, is known to have antifungal, antibacterial and α-glucosidase inhibitory activities. We studied the role of complex-type glycans attached to asparagine (Asn) 66 and Asn 110 to elucidate the role of carbohydrates in lectin activity and stability. Apart from the native lectin, the characteristics of a deglycosylated Escherichia coli expressed lectin, high-mannose oligosaccharides at both asparagines and its glycosylation mutants N66Q and N110Q expressed in Pichia pastoris, were compared to understand the relationship between glycosylation and activity. Far UV circular dichroism (CD) spectra, fluorescence emission maximum, hemagglutination assay show no change in secondary or tertiary structures or sugar-binding properties between wild-type and aforementioned recombinant lectins under physiological pH. But reduced agglutination activity and loss of tertiary structure are observed in the acidic pH range for the deglycosylated and the N110Q protein. In thermal and guanidine hydrochloride (GdnCl)-induced unfolding, the wild-type and high-mannose lectins possess higher stability compared with the deglycosylated recombinant lectin and both mutants, as measured by a higher Tm of denaturation or a greater free energy change, respectively. Reversibility experiments after thermal denaturation reveal that deglycosylated proteins tend to aggregate during thermal inactivation but the wild type shows a much greater recovery to the native state upon refolding. These results suggest that N-glycosylation in turmeric lectin is important for the maintenance of its proper folding upon changes in pH, and that the oligosaccharides help in maintaining the active conformation and prevent aggregation in unfolded or partially folded molecules. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dietary Broccoli Alters Rat Cecal Microbiota to Improve Glucoraphanin Hydrolysis to Bioactive Isothiocyanates

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Xiaoji Liu

2017-03-01

Full Text Available Broccoli consumption brings many health benefits, including reducing the risk of cancer and inflammatory diseases. The objectives of this study were to identify global alterations in the cecal microbiota composition using 16S rRNA sequencing analysis and glucoraphanin (GRP hydrolysis to isothiocyanates ex vivo by the cecal microbiota, following different broccoli diets. Rats were randomized to consume AIN93G (control or different broccoli diets; AIN93G plus cooked broccoli, a GRP-rich powder, raw broccoli, or myrosinase-treated cooked broccoli. Feeding raw or cooked broccoli for four days or longer both changed the cecal microbiota composition and caused a greater production of isothiocyanates ex vivo. A more than two-fold increase in NAD(PH: quinone oxidoreductase 1 activity of the host colon mucosa after feeding cooked broccoli for seven days confirmed the positive health benefits. Further studies revealed that dietary GRP was specifically responsible for the increased microbial GRP hydrolysis ex vivo, whereas changes in the cecal microbial communities were attributed to other broccoli components. Interestingly, a three-day withdrawal from a raw broccoli diet reversed the increased microbial GRP hydrolysis ex vivo. Findings suggest that enhanced conversion of GRP to bioactive isothiocyanates by the cecal microbiota requires four or more days of broccoli consumption and is reversible.

Dietary Broccoli Alters Rat Cecal Microbiota to Improve Glucoraphanin Hydrolysis to Bioactive Isothiocyanates.

Science.gov (United States)

Liu, Xiaoji; Wang, Yanling; Hoeflinger, Jennifer L; Neme, Bárbara P; Jeffery, Elizabeth H; Miller, Michael J

2017-03-10

Broccoli consumption brings many health benefits, including reducing the risk of cancer and inflammatory diseases. The objectives of this study were to identify global alterations in the cecal microbiota composition using 16S rRNA sequencing analysis and glucoraphanin (GRP) hydrolysis to isothiocyanates ex vivo by the cecal microbiota, following different broccoli diets. Rats were randomized to consume AIN93G (control) or different broccoli diets; AIN93G plus cooked broccoli, a GRP-rich powder, raw broccoli, or myrosinase-treated cooked broccoli. Feeding raw or cooked broccoli for four days or longer both changed the cecal microbiota composition and caused a greater production of isothiocyanates ex vivo. A more than two-fold increase in NAD(P)H: quinone oxidoreductase 1 activity of the host colon mucosa after feeding cooked broccoli for seven days confirmed the positive health benefits. Further studies revealed that dietary GRP was specifically responsible for the increased microbial GRP hydrolysis ex vivo, whereas changes in the cecal microbial communities were attributed to other broccoli components. Interestingly, a three-day withdrawal from a raw broccoli diet reversed the increased microbial GRP hydrolysis ex vivo. Findings suggest that enhanced conversion of GRP to bioactive isothiocyanates by the cecal microbiota requires four or more days of broccoli consumption and is reversible.

THE EFFECT OF LABELING INTENSITY, ESTIMATED BY REAL-TIME CONFOCAL LASER SCANNING MICROSCOPY, ON FLOW CYTOMETRIC APPEARANCE AND IDENTIFICATION OF IMMUNOCHEMICALLY LABELED MARINE DINOFLAGELLATES

NARCIS (Netherlands)

VRIELING, EG; DRAAIJER, A; VANZEIJL, WJM; PEPERZAK, L; GIESKES, WWC; VEENHUIS, M; Zeijl, Wilhelmus J.M. van

Two different fluorescein isothiocyanate (FITC) conjugates were used to analyze the effect of labeling intensity on the flow cytometric appearance of marine dinoflagellates labeled with antibodies that specifically recognized the outer cell wall. Location of the labeling was revealed by

Isolation and Biochemical Characterization of Apios Tuber Lectin

Directory of Open Access Journals (Sweden)

Eri Kenmochi

2015-01-01

Full Text Available Apios tuber lectin, named ATL, was isolated from Apios americana Medikus by two chromatography steps, hydrophobic chromatography and anion-exchange chromatography. The minimum concentration required for the hemagglutination activity toward rabbit erythrocytes of ATL was 4 μg/mL. ATL was composed of a homodimer of 28.4 kDa subunits. The amino acid sequence of ATL was similar to those of other legume lectins. The lectin showed moderate stability toward heating and acidic pH, and the binding affinity against several monosaccharides, such as D-glucosamine and D-galactosamine. ATL also bound to desialylated or agalactosylated glycoproteins such as asialo and agalacto transferrin. ATL decreased the transepithelial electrical resistance across human intestinal Caco-2 cell monolayers, suggesting the effect on the tight junction-mediated paracellular transport.

Lectins in fish skin: do they play a role in host-monogenean interactions?

Science.gov (United States)

Buchmann, K

2001-09-01

Mucus samples from rainbow trout skin with or without infections by Gyrodactylus derjavini were tested for the presence of lectins reacting with mannose, galactose and lactose. The samples inhibited the binding of biotinylated lectins (from Canavalia ensiformis, Artocarpus integrifolia and Erythrina corallodendron, respectively) to microtitre plates with covalently bound carbohydrates (mannopyranoside, galactopyranoside and lactose, respectively). However, the inhibition of C. ensiformis and A. integrifolia lectins was slightly greater when mucus from infected (but recovering) fish was used, suggesting an increase of mannose and galactose binding lectins in fish skin exposed to parasites. As mannose, galactose and lactose are present on the glycocalyx of Gyrodactylus derjavini, it is suggested that lectins could play a dual role in interactions between fish hosts and their monogenean parasites. Thus, recognition between parasite and host and also host responses towards parasite infections could both, at least partly, involve carbohydrate-lectin binding.

Mitogenic activity of new lectins from seeds of wild Artocarpus species from Vietnam.

Science.gov (United States)

Blasco, E; Ngoc, L D; Aucouturier, P; Preud'Homme, J L; Barra, A

1996-05-01

Proliferative response of human peripheral blood mononuclear cells (PBMC) stimulated by new lectins purified from seeds of differents Artocarpus species from Vietnam (A. asperulus, A. heterophyllus, A. masticata, A. melinoxylus, A. parva and A. petelotii) was studied and compared to those of the lectin jacalin purified from jackfruit (A. heterophyllus) seeds collected in the island La Réunion. All lectins stimulated human PBMC to proliferate, with a variable efficiency of the mitogenic activity. Phenotypic analysis of cells recovered after 7 day-cultures showed that these lectins mostly stimulated CD4+ T lymphocytes. These results suggest that these lectins from different Artocarpus species are similar in terms of their mitogenic activity although their structural features are not identical.

Appearance and cellular distribution of lectin-like receptors for alpha 1-acid glycoprotein in the developing rat testis

DEFF Research Database (Denmark)

Andersen, U O; Bøg-Hansen, T C; Kirkeby, S

1996-01-01

A histochemical avidin-biotin technique with three different alpha 1-acid glycoprotein glycoforms showed pronounced alterations in the cellular localization of two alpha 1-acid glycoprotein lectin-like receptors during cell differentiation in the developing rat testis. The binding of alpha 1-acid...

Preparation of Ulex europaeus lectin-gliadin nanoparticle conjugates and their interaction with gastrointestinal mucus.

Science.gov (United States)

Ezpeleta, I; Arangoa, M A; Irache, J M; Stainmesse, S; Chabenat, C; Popineau, Y; Orecchioni, A M

1999-11-25

One approach to improve the bioavailability and efficiency of drugs consists of the association of a ligand (i.e. lectins), showing affinity for biological structures located on the mucosa surfaces, to nanoparticulate drug delivery systems. In this context, Ulex europaeus lectin-gliadin nanoparticle conjugates (UE-GNP) were prepared with the aim of evaluating their in vitro bioadhesive properties. The lectin was fixed by a covalent procedure to gliadin nanoparticles by a two-stage carbodiimide method. Typically, the amount of bound lectin was calculated to be approximately 15 microg lectin/mg nanoparticle, which represented a coupling efficiency of approximately 16% of the initial lectin concentration. In addition, the activity of these conjugates was tested with bovine submaxillary gland mucin (BSM) and the level of binding to this mucin was always much greater with UE-GNP than with controls (gliadin nanoparticles). However, the presence of 50 micromol fucose, which is the reported specific sugar for U. europaeus lectin, specifically inhibited the activity of these conjugates and, therefore, the UE-GNP binding to BSM was attenuated by 70%. These results clearly showed that the activity and specificity of U. europaeus lectin was preserved after covalent coupling to these biodegradable carriers.

Interactions of soybean lectin, soyasaponins, and glycinin with rabbit jejunal mucosa in vitro

Energy Technology Data Exchange (ETDEWEB)

Alvarez, J.R.; Torres-Pinedo, R.

1982-09-01

Mucosal samples from rabbit jejunum were incubated (30 min, 25 degrees C) with (/sup 125/I)glycinin in the presence of buffer, soybean lectin (50 micrograms/ml) soyasaponins (1 mg/ml), or both lectin and saponins. The mucosal uptake of (/sup 125/I)glycinin was negligible with buffer, and increased progressively with additions of soybean lectin (P less than 0.05), soyasaponins (P less than 0.005), and both (P less than 0.0001). The stimulation of uptake by lectin and saponins together was greater than the sum of their individual effects (P less than 0.0005). The effect of soybean lectin on glycinin uptake was concentration dependent, reaching a maximum at approximately 50 micrograms/ml for the stimulation of uptake in the presence of saponins, and was inhibited by D-GaINAc. Although the mechanisms involved in mucosal uptake of glycinin cannot be described from these data, we have assumed the presence of two independent pathways for lectin-stimulated and saponin-induced uptakes. In addition, we have proposed that soybean lectin, by binding to terminal galactoside sites at the enterocyte apical membrane, enhances a crenator effect of saponins that leads to increasing leakage of glycinin into the cell.

Structure of a lectin with antitumoral properties in king bolete (Boletus edulis) mushrooms.

Science.gov (United States)

Bovi, Michele; Carrizo, Maria E; Capaldi, Stefano; Perduca, Massimiliano; Chiarelli, Laurent R; Galliano, Monica; Monaco, Hugo L

2011-08-01

A novel lectin has been isolated from the fruiting bodies of the common edible mushroom Boletus edulis (king bolete, penny bun, porcino or cep) by affinity chromatography on a chitin column. We propose for the lectin the name BEL (B. edulis lectin). BEL inhibits selectively the proliferation of several malignant cell lines and binds the neoplastic cell-specific T-antigen disaccharide, Galβ1-3GalNAc. The lectin was structurally characterized: the molecule is a homotetramer and the 142-amino acid sequence of the chains was determined. The protein belongs to the saline-soluble family of mushroom fruiting body-specific lectins. BEL was also crystallized and its three-dimensional structure was determined by X-ray diffraction to 1.15 Å resolution. The structure is similar to that of Agaricus bisporus lectin. Using the appropriate co-crystals, the interactions of BEL with specific mono- and disaccharides were also studied by X-ray diffraction. The six structures of carbohydrate complexes reported here provide details of the interactions of the ligands with the lectin and shed light on the selectivity of the two distinct binding sites present in each protomer.

"Click" saccharide/beta-lactam hybrids for lectin inhibition.

Science.gov (United States)

Palomo, Claudio; Aizpurua, Jesus M; Balentová, Eva; Azcune, Itxaso; Santos, J Ignacio; Jiménez-Barbero, Jesús; Cañada, Javier; Miranda, José Ignacio

2008-06-05

Hybrid glycopeptide beta-lactam mimetics designed to bind lectins or carbohydrate recognition domains in selectins have been prepared according to a "shape-modulating linker" design. This approach was implemented using the azide-alkyne "click" cycloaddition reaction, and as shown by NMR/MD experiments, binding of the resulting mimetics to Ulex Europaeus Lectin-1 (UEL-1) occurred after a "bent-to-extended" conformational change around a partially rotatable triazolylmethylene moiety.

Hyphal walls of isolated lichen fungi

International Nuclear Information System (INIS)

Galun, M.; Braun, A.; Frensdorff, A.; Galun, E.

1976-01-01

The hyphal walls of three mycobionts, isolated from the lichens Xanthoria parietina, Tornabenia intricata and Sarcogyne sp. were investigated by two techniques: microaudiography of fungal colonies exposed to radioactive carbohydrate precursors; and binding, in vivo, of fluorescein conjugated lectins to hyphal walls of such colonies. N-( 3 H) acetylglucosamine was readily incorporated into tips, young hyphal walls and septa of the three mycobionts and the free-living fungus Trichoderma viride, but not into Phytophthora citrophthora, indicating that chitin is a major component of the mycobionts' hyphal walls. All three mycobionts, but neither of the free-living fungi, incorporated ( 3 H) mannose and ( 3 H) mannitol into their hyphal walls. Fluorescein-conjugated wheat germ agglutinin was bound to the hyphal walls of the three mycobionts and T. viride, but not to the walls of P. citrophthora; the binding pattern was similar to the grain pattern obtained in audiographs after short N-( 3 H) acetylglucosamine labelling. As wheat germ agglutinin binds specifically to chitin oligomers, the lectin binding tests further confirmed that chitin is a mycobiont hyphal wall component. Binding characteristics of several fluorescein-conjugated lectins to the three mycobionts indicated that this technique can yield useful information concerning the chemical composition of hyphal wall surfaces. (orig./AJ) [de

Trihydroxytrioxatriangulene - An Extended Fluorescein and a Ratiometric pH Sensor

DEFF Research Database (Denmark)

Westerlund, Fredrik; Hildebrandt, Christoffer Boli; Sørensen, Thomas Just

2010-01-01

Fluorescein ver. 2.0: A new, highly fluorescent, pH-sensitive trihydroxytrioxatriangulenium dye (H-TOTA) has been synthesised and characterised. The dye is closely related to fluorescein and may be considered to be a two-dimensional extended version. This new dye can exist in four different proto...... protonation states (see graphic) depending on the pH, and its use as a sensitive fluorescent ratiometric pH probe in a physiological buffer is demonstrated....

Purification of a thermostable antinociceptive lectin isolated from Andira anthelmia.

Science.gov (United States)

Nascimento, Kyria Santiago; Nascimento, Francisco Lucas Faustino do; Silva, Mayara Torquato Lima; Nobre, Camila Bezerra; Moreira, Cleane Gomes; Brizeno, Luiz André Cavalcante; da Ponte, Edson Lopes; Assreuy, Ana Maria Sampaio; Cavada, Benildo Sousa

2016-06-01

Andira anthelmia (tribe Dalbergieae), a plant from Brazilian Amazon, possesses a seed lectin that was purified by affinity chromatography in sepharose-mannose. This novel Dalbergieae lectin, named AAL, agglutinated rabbit erythrocytes treated with trypsin. The hemagglutinating activity of AAL was maintained after incubation at a wide range of temperature (40 to 70 °C) and pH, was shown to be dependent on divalent cations, and was inhibited by d-mannose and d-sucrose. AAL showed an electrophoretic profile in sodium dodecyl sulfate-polyacrylamide gel electrophoresis similar to other lectins of the tribe Dalbergieae, presenting a double band of molecular weight with approximately 20 kDa and other minor bands of 17, 15, and 13 kDa, being the smaller fragment glycosylated. AAL injected by intravenous route in mice showed antinociceptive activity in two behavioral tests (writhing and formalin). In the writhing test induced by acetic acid, AAL showed inhibitory effect at 0.01 mg/kg (68%), 0.1 mg/kg (46%) and 1 mg/kg (74%). In the formalin test, AAL (0.1 mg/kg) inhibited by 48% the licking time in the inflammatory phase, an effect that was recovered by the lectin association with mannose. In conclusion, AAL presents analgesic effect involving the lectin domain via peripheral mechanisms of inflammatory nociception. This activity highlights the importance of lectins as tools to be used for understanding the interaction of protein-carbohydrate in processes associated to inflammatory pain. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

A fluorometric lateral flow assay for visual detection of nucleic acids using a digital camera readout.

Science.gov (United States)

Magiati, Maria; Sevastou, Areti; Kalogianni, Despina P

2018-06-04

A fluorometric lateral flow assay has been developed for the detection of nucleic acids. The fluorophores phycoerythrin (PE) and fluorescein isothiocyanate (FITC) were used as labels, while a common digital camera and a colored vinyl-sheet, acting as a cut-off optical filter, are used for fluorescence imaging. After DNA amplification by polymerase chain reaction (PCR), the biotinylated PCR product is hybridized to its complementary probe that carries a poly(dA) tail at 3΄ edge and then applied to the lateral flow strip. The hybrids are captured to the test zone of the strip by immobilized poly(dT) sequences and detected by streptavidin-fluorescein and streptavidin-phycoerythrin conjugates, through streptavidin-biotin interaction. The assay is widely applicable, simple, cost-effective, and offers a large multiplexing potential. Its performance is comparable to assays based on the use of streptavidin-gold nanoparticles conjugates. As low as 7.8 fmol of a ssDNA and 12.5 fmol of an amplified dsDNA target were detectable. Graphical abstract Schematic presentation of a fluorometric lateral flow assay based on fluorescein and phycoerythrin fluorescent labels for the detection of single-stranded (ssDNA) and double-stranded DNA (dsDNA) sequences and using a digital camera readout. SA: streptavidin, BSA: Bovine Serum Albumin, B: biotin, FITC: fluorescein isothiocyanate, PE: phycoerythrin, TZ: test zone, CZ: control zone.

Integrated Microfluidic Lectin Barcode Platform for High-Performance Focused Glycomic Profiling

Science.gov (United States)

Shang, Yuqin; Zeng, Yun; Zeng, Yong

2016-02-01

Protein glycosylation is one of the key processes that play essential roles in biological functions and dysfunctions. However, progress in glycomics has considerably lagged behind genomics and proteomics, due in part to the enormous challenges in analysis of glycans. Here we present a new integrated and automated microfluidic lectin barcode platform to substantially improve the performance of lectin array for focused glycomic profiling. The chip design and flow control were optimized to promote the lectin-glycan binding kinetics and speed of lectin microarray. Moreover, we established an on-chip lectin assay which employs a very simple blocking method to effectively suppress the undesired background due to lectin binding of antibodies. Using this technology, we demonstrated focused differential profiling of tissue-specific glycosylation changes of a biomarker, CA125 protein purified from ovarian cancer cell line and different tissues from ovarian cancer patients in a fast, reproducible, and high-throughput fashion. Highly sensitive CA125 detection was also demonstrated with a detection limit much lower than the clinical cutoff value for cancer diagnosis. This microfluidic platform holds the potential to integrate with sample preparation functions to construct a fully integrated “sample-to-answer” microsystem for focused differential glycomic analysis. Thus, our technology should present a powerful tool in support of rapid advance in glycobiology and glyco-biomarker development.

Growth factors G-CSF and GM-CSF differentially preserve chemotaxis of neutrophils aging in vitro

NARCIS (Netherlands)

Wolach, Baruch; van der Laan, Luc J. W.; Maianski, Nikolai A.; Tool, Anton T. J.; van Bruggen, Robin; Roos, Dirk; Kuijpers, Taco W.

2007-01-01

OBJECTIVE: The ability of human neutrophils to migrate was studied during culture in vitro. METHODS: Neutrophils were isolated from human blood and cultured at 37 degrees C. Apoptosis was determined by Annexin-V fluorescein isothiocyanate binding. Receptor expression was measured by fluorescence in

A sperm-agglutinating lectin from seeds of Jack fruit (Artocarpus heterophyllus).

Science.gov (United States)

Namjuntra, P; Muanwongyathi, P; Chulavatnatol, M

1985-04-30

A lectin specific for N-acetylgalactosamine was isolated from seed extract of Jack fruit (Artocarpus heterophyllus) by ammonium sulfate precipitation, followed by affinity chromatography on a Affigel-galactosamine-agarose column. The lectin possessed agglutinating activities for human and rat sperm as well as human red blood cells. It was found to have Mr = 62,000 consisting of two dissimilar subunits of Mr = 18,000 and 13,000. It also cross-reacted with an antibody against the lectin of Osage Orange (Maclura pomifera).

Microscopic oxygen imaging based on fluorescein bleaching efficiency measurements

DEFF Research Database (Denmark)

Beutler, Martin; Heisterkamp, Ines M.; Piltz, Bastian

2014-01-01

by a charge-coupled-device (ccd) camera mounted on a fluorescence microscope allowed a pixelwise estimation of the ratio function in a microscopic image. Use of a microsensor and oxygen-consuming bacteria in a sample chamber enabled the calibration of the system for quantification of absolute oxygen......Photobleaching of the fluorophore fluorescein in an aqueous solution is dependent on the oxygen concentration. Therefore, the time-dependent bleaching behavior can be used to measure of dissolved oxygen concentrations. The method can be combined with epi-fluorescence microscopy. The molecular...... states of the fluorophore can be expressed by a three-state energy model. This leads to a set of differential equations which describe the photobleaching behavior of fluorescein. The numerical solution of these equations shows that in a conventional wide-field fluorescence microscope, the fluorescence...

Quantitation of two endogenous lactose-inhibitable lectins in embryonic and adult chicken tissues

International Nuclear Information System (INIS)

Beyer, E.C.; Barondes, S.H.

1982-01-01

Two lactose-binding lectins from chicken tissues, chicken-lactose-lectin-I (CLL-I) and chicken-lactose-lectin-II (CLL-II) were quantified with a radioimmunoassay in extracts of a number of developing and adult chicken tissues. Both lectins could be measured in the same extract without separation, because they showed no significant immunological cross- reactivity. Many embryonic and adult tissues, including brain, heart, intestine, kidney, liver, lung, muscle, pancreas, and spleen, contained one or both lectins, although their concentrations differed markedly. For example, embryonic muscle, the richest source of CLL-I contained only traces of CLL-II whereas embryonic kidney, a very rich source of CLL-II contained substantial CLL-I. In both muscle and kidney, lectin levels in adulthood were much lower than in the embryonic state. In contrast, CLL-I in liver and CLL-II in intestine were 10-fold to 30-fold more concentrated in the adult than in the 15-d embryo. CLL-I and CLL-II from several tissues were purified by affinity chromatography and their identity in the various tissues was confirmed by polyacrylamide gel electrophoresis, isoelectric focusing, and peptide mapping. The results suggest that these lectins might have different functions in the many developing and adult tissues in which they are found

DMPD: C-type lectin receptors in antifungal immunity. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 18160296 C-type lectin receptors in antifungal immunity. Willment JA, Brown GD. Tre...nds Microbiol. 2008 Jan;16(1):27-32. Epub 2007 Dec 21. (.png) (.svg) (.html) (.csml) Show C-type lectin receptors in antifun...gal immunity. PubmedID 18160296 Title C-type lectin receptors in antifungal immunity. Author

Purification and characterization of a new type lactose-binding Ulex europaeus lectin by affinity chromatography.

Science.gov (United States)

Konami, Y; Yamamoto, K; Osawa, T

1991-02-01

A new type lactose-binding lectin was purified from extracts of Ulex europaeus seeds by affinity chromatography on a column of galactose-Sepharose 4B, followed by gel filtration on Sephacryl S-300. This lectin, designated as Ulex europaeus lectin III (UEA-III), was found to be inhibited by lactose. The dimeric lectin is a glycoprotein with a molecular mass of 70,000 Da; it consists of two apparently identical subunits of a molecular mass of 34,000 Da. Compositional analysis showed that this lectin contains 30% carbohydrate and a large amount of aspartic acid, serine and valine, but no sulfur-containing amino acids. The N-terminal amino-acid sequences of L-fucose-binding Ulex europaeus lectin I (UEA-I) and di-N-acetylchitobiose-binding Ulex europaeus lectin II (UEA-II), both of which we have already purified and characterized, and that of UEA-III were determined and compared.

Identification and characterization of a novel legume-like lectin ...

Indian Academy of Sciences (India)

A legume-type lectin (L-lectin) gene of the red algae Gracilaria fisheri (GFL) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of GFL was 1714 bp and contained a 1542 bp open reading frame encoding 513 amino acids with a predicted molecular mass of 56.5 kDa. Analysis of the putative ...

Direct analysis of the lectin reactivity of alpha-fetoprotein in maternal serum by crossed affinity radio-immunoelectrophoresis

International Nuclear Information System (INIS)

Kerckaert, J.P.; Bayard, B.; Biserte, G.; Puech, F.; Codaccioni, X.

1980-01-01

Affinity experiments with the lentil (Lens culinaris) lectin have revealed the existence of two distinct molecular populations of alpha-fetoprotein: lectin reactive and lectin non-reactive. Using a combination of crossed lectin immunoelectrophoresis and radio-immunoelectrophoresis, it has been possible to obtain directly the lentil lectin affinity patterns of alpha-fetoprotein present in maternal sera. The lentil lectin reactivity of maternal alpha-fetoprotein decreases almost linearly with the gestational age from week 15 to 35. (Auth.)

Evaluation of intravenous fluorescein in intradermal allergy testing in psittacines.

Science.gov (United States)

Nett, Claudia S; Hosgood, Giselle; Heatley, J Jill; Foil, Carol S; Tully, Thomas N

2003-12-01

This study was designed to improve the clinical feasibility of intradermal skin testing of psittacine birds using intravenous fluorescein stain. Twenty-five healthy, anaesthetized Hispaniolan Amazon parrots (Amazona ventralis) were injected intravenously with 10 mg kg-1 fluorescein-sodium 1% followed by intradermal injections of 0.02 mL phosphate-buffered saline, histamine phosphate (1:100,000 w/v) and codeine phosphate (1:100,000 w/v) at the sternal apteria. Wheal diameters of reaction sites were measured grossly and under illumination with a Wood's lamp after 5 and 10 min. Fluorescence-enhanced injection sites were scored between 0 and 2, with 0 equivalent to normal skin and 2 equivalent to a plucked feather follicle. The presence of a fluorescent halo around intradermal injections was also recorded. Under Wood's light illumination at 10 min, histamine and saline were evaluated as positive and negative controls, respectively, based on a positive test having a halo and a score of 2. Sensitivity and specificity were each 76% for halo, 84 and 42% for score and 64 and 77% for combination of score and halo, respectively. Further, mean histamine reactions were significantly larger than codeine phosphate and saline (8.8 +/- 0.4 mm; 7.2 +/- 0.3 mm; 5.9 +/- 0.6 mm); however, this finding was not consistent in individual birds. Wheal size, halo presence and score were affected by site location independent from the injected compound. Intravenous fluorescein improved the readability of avian skin tests; however, the compounds tested raised inconsistent reactions in wheal size, score or halo presence. The compound-independent site effect raises concern on the validity of avian skin testing and warrants investigation of other techniques such as in vitro allergy testing. Based on our findings, intradermal allergy testing in psittacines with or without fluorescein is unreliable and cannot be recommended for practical clinical use.

Structural studies of the mechanism for biosensing antibiotics in a fluorescein-labeled β-lactamase

Directory of Open Access Journals (Sweden)

Wong Kwok-Yin

2011-03-01

Full Text Available Abstract Background β-lactamase conjugated with environment-sensitive fluorescein molecule to residue 166 on the Ω-loop near its catalytic site is a highly effective biosensor for β-lactam antibiotics. Yet the molecular mechanism of such fluorescence-based biosensing is not well understood. Results Here we report the crystal structure of a Class A β-lactamase PenP from Bacillus licheniformis 749/C with fluorescein conjugated at residue 166 after E166C mutation, both in apo form (PenP-E166Cf and in covalent complex form with cefotaxime (PenP-E166Cf-cefotaxime, to illustrate its biosensing mechanism. In the apo structure the fluorescein molecule partially occupies the antibiotic binding site and is highly dynamic. In the PenP-E166Cf-cefatoxime complex structure the binding and subsequent acylation of cefotaxime to PenP displaces fluorescein from its original location to avoid steric clash. Such displacement causes the well-folded Ω-loop to become fully flexible and the conjugated fluorescein molecule to relocate to a more solvent exposed environment, hence enhancing its fluorescence emission. Furthermore, the fully flexible Ω-loop enables the narrow-spectrum PenP enzyme to bind cefotaxime in a mode that resembles the extended-spectrum β-lactamase. Conclusions Our structural studies indicate the biosensing mechanism of a fluorescein-labelled β-lactamase. Such findings confirm our previous proposal based on molecular modelling and provide useful information for the rational design of β-lactamase-based biosensor to detect the wide spectrum of β-lactam antibiotics. The observation of increased Ω-loop flexibility upon conjugation of fluorophore may have the potential to serve as a screening tool for novel β-lactamase inhibitors that target the Ω-loop and not the active site.

Innate Immunity in Lobsters: Partial Purification and Characterization of a Panulirus cygnus Anti-A Lectin.

Science.gov (United States)

Flower, Robert L P

2012-01-01

A lectin detected in haemolymph from the Australian spiny lobster Panulirus cygnus agglutinated human ABO Group A cells to a higher titre than Group O or B. The lectin also agglutinated rat and sheep erythrocytes, with reactivity with rat erythrocytes strongly enhanced by treatment with the proteolytic enzyme papain, an observation consistent with reactivity via a glycolipid. The lectin, purified by affinity chromatography on fixed rat-erythrocyte stroma, was inhibited equally by N-acetylglucosamine and N-acetylgalactosamine. Comparison of data from gel filtration of haemolymph (behaving as a 1,800,000 Da macromolecule), and polyacrylamide gel electrophoresis of purified lectin (a single 67,000 Da band), suggested that in haemolymph the lecin was a multimer. The purified anti-A lectin autoprecipitated unless the storage solution contained chaotropic inhibitors (125 mmol/L sucrose: 500 mmol/L urea). The properties of this anti-A lectin and other similar lectins are consistent with a role in innate immunity in these invertebrates.

Bioavailability of Isothiocyanates From Broccoli Sprouts in Protein, Lipid, and Fiber Gels

NARCIS (Netherlands)

Oliviero, Teresa; Lamers, Simone; Capuano, Edoardo; Dekker, Matthijs; Verkerk, Ruud

2018-01-01

Scope: Optimization of bioavailability of dietary bioactive health-beneficial compounds is as important as increasing their concentration in foods. The aim of this study is to explore the change in bioavailability of isothiocyanates (ITCs) in broccoli sprouts incorporated in protein, fiber, and

No metabolic effects of mustard allyl-isothiocyanate compared with placebo in men

NARCIS (Netherlands)

Langeveld, Mirjam; Tan, Chong Yew; Soeters, Maarten R.; Virtue, Samuel; Watson, Laura Pe; Murgatroyd, Peter R.; Ambler, Graeme K.; Vidal-Puig, Santiago; Chatterjee, Krishna V.; Vidal-Puig, Antonio

2017-01-01

Background: Induction of nonshivering thermogenesis can be used to influence energy balance to prevent or even treat obesity. The pungent component of mustard, allyl-isothiocyanate (AITC), activates the extreme cold receptor transient receptor potential channel, subfamily A, member 1 and may thus

Multivalent Carbohydrate-Lectin Interactions: How Synthetic Chemistry Enables Insights into Nanometric Recognition

Directory of Open Access Journals (Sweden)

René Roy

2016-05-01

Full Text Available Glycan recognition by sugar receptors (lectins is intimately involved in many aspects of cell physiology. However, the factors explaining the exquisite selectivity of their functional pairing are not yet fully understood. Studies toward this aim will also help appraise the potential for lectin-directed drug design. With the network of adhesion/growth-regulatory galectins as therapeutic targets, the strategy to recruit synthetic chemistry to systematically elucidate structure-activity relationships is outlined, from monovalent compounds to glyco-clusters and glycodendrimers to biomimetic surfaces. The versatility of the synthetic procedures enables to take examining structural and spatial parameters, alone and in combination, to its limits, for example with the aim to produce inhibitors for distinct galectin(s that exhibit minimal reactivity to other members of this group. Shaping spatial architectures similar to glycoconjugate aggregates, microdomains or vesicles provides attractive tools to disclose the often still hidden significance of nanometric aspects of the different modes of lectin design (sequence divergence at the lectin site, differences of spatial type of lectin-site presentation. Of note, testing the effectors alone or in combination simulating (pathophysiological conditions, is sure to bring about new insights into the cooperation between lectins and the regulation of their activity.

C-type lectins do not act as functional receptors for filovirus entry into cells

Energy Technology Data Exchange (ETDEWEB)

Matsuno, Keita; Nakayama, Eri; Noyori, Osamu [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo (Japan); Marzi, Andrea; Ebihara, Hideki [Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, MT (United States); Irimura, Tatsuro [Graduate School of Pharmaceutical Science, University of Tokyo, Tokyo (Japan); Feldmann, Heinz [Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, MT (United States); Takada, Ayato, E-mail: atakada@czc.hokudai.ac.jp [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo (Japan)

2010-12-03

Research highlights: {yields} Filovirus glycoprotein (GP) having a deficient receptor binding region were generated. {yields} Mutant GPs mediated virus entry less efficiently than wild-type GP. {yields} Mutant GPs bound to C-type lectins but not mediated entire steps of cellular entry. {yields} C-type lectins do not independently mediate filovirus entry into cells. {yields} Other molecule(s) are required for C-type lectin-mediated entry of filoviruses. -- Abstract: Cellular C-type lectins have been reported to facilitate filovirus infection by binding to glycans on filovirus glycoprotein (GP). However, it is not clearly known whether interaction between C-type lectins and GP mediates all the steps of virus entry (i.e., attachment, internalization, and membrane fusion). In this study, we generated vesicular stomatitis viruses pseudotyped with mutant GPs that have impaired structures of the putative receptor binding regions and thus reduced ability to infect the monkey kidney cells that are routinely used for virus propagation. We found that infectivities of viruses with the mutant GPs dropped in C-type lectin-expressing cells, parallel with those in the monkey kidney cells, whereas binding activities of these GPs to the C-type lectins were not correlated with the reduced infectivities. These results suggest that C-type lectin-mediated entry of filoviruses requires other cellular molecule(s) that may be involved in virion internalization or membrane fusion.

C-type lectins do not act as functional receptors for filovirus entry into cells

International Nuclear Information System (INIS)

Matsuno, Keita; Nakayama, Eri; Noyori, Osamu; Marzi, Andrea; Ebihara, Hideki; Irimura, Tatsuro; Feldmann, Heinz; Takada, Ayato

2010-01-01

Research highlights: → Filovirus glycoprotein (GP) having a deficient receptor binding region were generated. → Mutant GPs mediated virus entry less efficiently than wild-type GP. → Mutant GPs bound to C-type lectins but not mediated entire steps of cellular entry. → C-type lectins do not independently mediate filovirus entry into cells. → Other molecule(s) are required for C-type lectin-mediated entry of filoviruses. -- Abstract: Cellular C-type lectins have been reported to facilitate filovirus infection by binding to glycans on filovirus glycoprotein (GP). However, it is not clearly known whether interaction between C-type lectins and GP mediates all the steps of virus entry (i.e., attachment, internalization, and membrane fusion). In this study, we generated vesicular stomatitis viruses pseudotyped with mutant GPs that have impaired structures of the putative receptor binding regions and thus reduced ability to infect the monkey kidney cells that are routinely used for virus propagation. We found that infectivities of viruses with the mutant GPs dropped in C-type lectin-expressing cells, parallel with those in the monkey kidney cells, whereas binding activities of these GPs to the C-type lectins were not correlated with the reduced infectivities. These results suggest that C-type lectin-mediated entry of filoviruses requires other cellular molecule(s) that may be involved in virion internalization or membrane fusion.

Lectin histochemical evaluation of glycoconjugates in dog efferent ductules.

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Wakui, S; Furusato, M; Takahashi, H; Motoya, M; Ushigome, S

1996-06-01

Glycoconjugates in the epithelial cells of the efferent ductules in the dog were investigated using lectin histochemistry. These ductules connect the extratesticular rete with the epididymis. The epithelium of the ductules consisted both of ciliated and nonciliated cells. Whereas the apical zone of ciliated cells showed selective binding with WGA, SWGA, SNA, MAA and neuraminidase-PNA, that of nonciliated cells bound to all lectins used in the present study: WGA, SWGA, SNA, MAA, PNA, neuraminidase-PNA, RCA1, DBA and SBA. The nonciliated cells were divided into 3 types: type A cells which lacked both specific granules and vacuoles, type B cells which were characterised by a few specific apical vacuoles and many large specific granules, and type C cells which were characterised by some specific apical vacuoles and small basal granules. The specific granules and vacuoles of type B cells showed binding with WGA, SWGA and MAA. The specific granules of type C cells showed binding with WGA, SWGA, SNA, MAA, PNA and neuraminidase-PNA, while their specific vacuoles showed binding with WGA, SWGA, SNA and MAA. The Golgi zone both of ciliated and type A cells did not bind with any lectins used in this study, while type B and C cells showed similar lectin binding patterns between the Golgi zone and their specific granules. Specific lectin binding patterns revealed a different carbohydrate composition of each type of cell, indicating a biological difference between the ciliated cells and the 3 types of nonciliated cells in dog efferent ductules.

Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster

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Nieves Baenas

2016-02-01

Full Text Available We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo, a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L for 10 days, containing high amounts of glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforaphene and raphasatin, respectively. We demonstrate that Drosophila melanogaster takes up and metabolizes isothiocyanates from radish sprouts through the detection of the metabolite sulforaphane-cysteine in fly homogenates. Moreover, we report a decrease in the glucose content of flies, an upregulation of spargel expression, the Drosophila homolog of the mammalian PPARγ-coactivator 1 α, as well as the inhibition of α-amylase and α-glucosidase in vitro. Overall, we show that the consumption of radish sprouts affects energy metabolism in Drosophila melanogaster which is reflected by lower glucose levels and an increased expression of spargel, a central player in mitochondrial biogenesis. These processes are often affected in chronic diseases associated with aging, including type II diabetes mellitus.

Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster

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Baenas, Nieves; Piegholdt, Stefanie; Schloesser, Anke; Moreno, Diego A.; García-Viguera, Cristina; Rimbach, Gerald; Wagner, Anika E.

2016-01-01

We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo), a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L) for 10 days, containing high amounts of glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforaphene and raphasatin, respectively. We demonstrate that Drosophila melanogaster takes up and metabolizes isothiocyanates from radish sprouts through the detection of the metabolite sulforaphane-cysteine in fly homogenates. Moreover, we report a decrease in the glucose content of flies, an upregulation of spargel expression, the Drosophila homolog of the mammalian PPARγ-coactivator 1 α, as well as the inhibition of α-amylase and α-glucosidase in vitro. Overall, we show that the consumption of radish sprouts affects energy metabolism in Drosophila melanogaster which is reflected by lower glucose levels and an increased expression of spargel, a central player in mitochondrial biogenesis. These processes are often affected in chronic diseases associated with aging, including type II diabetes mellitus. PMID:26901196

Immunocytochemical localisation of phloem lectin from Cucurbita maxima using peroxidase and colloidal-gold labels.

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Smith, L M; Sabnis, D D; Johnson, R P

1987-04-01

Antibodies were raised against lectin purified from the sieve-tube exudate of Cucurbita maxima. Immunocytochemistry, using peroxidase-labelled antibodies and Protein A-colloidal gold, was employed to determine the location of the lectin within the tissues and cells of C. maxima and other cucurbit species. The anti-lectin antibodies bound to P-protein aggregates in sieve elements and companion cells, predominantly in the extrafascicular phloem of C. maxima. This may reflect the low rate of translocation in these cells. Under the electron microscope, the lectin was shown to be a component of P-protein filaments and was also found in association with the sieve-tube reticulum which lines the plasmalemma. The anti-lectin antibodies reacted with sieve-tube proteins from other species of the genus Cucurbita but showed only limited reaction with other genera. We suggest that the lectin serves to anchor P-protein filaments and associated proteins to the parietal layer of sieve elements.

Does Fundus Fluorescein Angiography Procedure Affect Ocular Pulse Amplitude?

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Gökhan Pekel

2013-01-01

Full Text Available Purpose. This study examines the effects of fundus fluorescein angiography (FFA procedure on ocular pulse amplitude (OPA and intraocular pressure (IOP. Materials and Methods. Sixty eyes of 30 nonproliferative diabetic retinopathy patients (15 males, 15 females were included in this cross-sectional case series. IOP and OPA were measured with the Pascal dynamic contour tonometer before and after 5 minutes of intravenous fluorescein dye injection. Results. Pre-FFA mean OPA value was  mmHg and post-FFA mean OPA value was  mmHg (. Pre-FFA mean IOP value was  mmHg and post-FFA mean IOP value was  mmHg (. Conclusion. Although both mean OPA and IOP values were decreased after FFA procedure, the difference was not statistically significant. This clinical trial is registered with Australian New Zealand Clinical Trials Registry number ACTRN12613000433707.

Phylogenetic Analysis of C Type Lectin from Toxocara canis Infective Larvae and Comparison with the C Type Lectin Fam-ily in the Immune System of Mouse and Human

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Fazeleh ETEBAR

2018-03-01

Full Text Available Background: C type lectin (CTL family is a type of calcium-dependent proteins found in vertebrates and invertebrates. The objective of this study was to perform a comparative analysis and phylogenetic inferring for understanding the similarities and differences of carbohydrate recognition domain (CRD domain of Toxocara canis CTL and other nematodes, and similar C type lectin involved in the immune system of mouse and human as their host.Methods: The female T. canis was retrieved from the 2-6 months puppies (Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, 2015. To collect T. canis eggs, the worms were cultured for 5 d until they were embryonated. The hatching process was accelerated for collecting the stage 2 larvae, and the larvae were cultured for a week. A cDNA library was made from the total mRNA of T. canis infective larvae. The PCR amplification for C type lectin gene was performed and the amino acids were analyzed using the alignment method and the construction of phylogenetic tree.Results: The suspension sample maintained at 30 ºC for four weeks could embryonate 90%-100% of eggs. T. canis CTL gene was 657 bp in length and encoded a protein with 219 amino acids. The CTL of species of Strongylida order were closely placed in the tree, whereas the members of Ascaridida orders were located in a separate branch. High levels of similarity (36%-44% and conservation of C type lectin from T. canis with mouse and human C type lectins. Its C type lectin showed a higher similarity with asialoglycoprotein receptor (ASGPR, macrophage lectin, dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN, MINCLE receptor of mouse and human.Conclusion: Analysis of CRD domain of C type lectin protein could make a better understanding of their role in the interaction of nematode parasite with their hosts.

STUDY OF AZOSPIRILLUM LECTINS INFLUENCE ON HYDROGEN PEROXIDE PRODUCTION IN WHEAT-ROOTS

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Alen’kina S.A.

2009-12-01

Full Text Available It was found that two cell-surface lectins isolated from the nitrogen-fixing soil bacterium Azospirillum brasilense Sp7 and from its mutant defective in lectin activity, A. brasilense Sp7.2.3 can stimulate rapid formation of hydrogen peroxide, associated with an increase in the activities of oxalate oxidase and peroxidase in the roots of wheat seedlings. The most advantageous and most rapidly induced pathway of hydrogen peroxide formation was the oxidation of oxalic acid by oxalate oxidase because in this case, a 10-min treatment of the roots with the lectins at 10 µg ml-1 was sufficient. The data from this study attest that the Azospirillum lectins can act as inducers of adaptation processes in the roots of wheat seedlings.

Labeling of lectin receptors during the cell cycle.

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Garrido, J

1976-12-01

Labeling of lectin receptors during the cell cycle. (Localizabión de receptores para lectinas durante el ciclo celular). Arch. Biol. Med. Exper. 10: 100-104, 1976. The topographic distribution of specific cell surface receptors for concanavalin A and wheat germ agglutinin was studied by ultrastructural labeling in the course of the cell cycle. C12TSV5 cells were synchronized by double thymidine block or mechanical selection (shakeoff). They were labeled by means of lectin-peroxidase techniques while in G1 S, G2 and M phases of the cycle. The results obtained were similar for both lectins employed. Interphase cells (G1 S, G2) present a stlihtly discontinous labeling pattern that is similar to the one observed on unsynchronized cells of the same line. Cells in mitosis, on the contrary, present a highly discontinous distribution of reaction product. This pattern disappears after the cells enters G1 and is not present on mitotic cells fixed in aldehyde prior to labeling.

The Lectin Complement Pathway in Patients with Necrotizing Soft Tissue Infection

DEFF Research Database (Denmark)

Hansen, Marco Bo; Rasmussen, Lars S; Pilely, Katrine

2016-01-01

BACKGROUND: Mannose-binding lectin (MBL) and ficolins are pattern recognition molecules (PRMs) that play an important role during infection through activation of the lectin complement pathway. We assessed whether plasma PRM levels were associated with mortality in patients with necrotizing soft t...

Lectin Domains of Polypeptide GalNAc Transferases Exhibit Glycopeptide Binding Specificity

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Pedersen, Johannes W; Bennett, Eric P; Schjoldager, Katrine T-B G

2011-01-01

UDP-GalNAc:polypeptide a-N-acetylgalactosaminyltransferases (GalNAc-Ts) constitute a family of up to 20 transferases that initiate mucin-type O-glycosylation. The transferases are structurally composed of catalytic and lectin domains. Two modes have been identified for the selection...... of glycosylation sites by GalNAc-Ts: confined sequence recognition by the catalytic domain alone, and concerted recognition of acceptor sites and adjacent GalNAc-glycosylated sites by the catalytic and lectin domains, respectively. Thus far, only the catalytic domain has been shown to have peptide sequence...... on sequences of mucins MUC1, MUC2, MUC4, MUC5AC, MUC6, and MUC7 as well as a random glycopeptide bead library, we examined the binding properties of four different lectin domains. The lectin domains of GalNAc-T1, -T2, -T3, and -T4 bound different subsets of small glycopeptides. These results indicate...

PVA-Glutaraldehyde as support for lectin immobilization and affinity chromatography

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Moacyr Jesus Barreto de Melo Rêgo

2016-12-01

Full Text Available Immobilized lectins are a powerful biotechnological tool for separation and isolation of glycoconjugates. In the present study, polyvinyl alcohol (PVA and glutaraldehyde (GA were used as a support for Concanavalin A (Con A covalent immobilization and for entrapment of Parkia pendula seed gum (PpeG. Con A immobilization yielded approximately 30% and 0.6 M glucose solution was the minimum concentration able to elute fetuin from column. PVA-GA-PpeG column was efficiently recognized by pure P. pendula lectin (PpeL. These findings indicate that PVA-GA interpenetrated network showed to be an efficient support for lectin covalent immobilization and as affinity chromatography matrix after trapping of PpeG.

Clinical Investigation of Radiation Retinopathy Fundus and Fluorescein Angiographic Features

Institute of Scientific and Technical Information of China (English)

LiMei; QiuGT

1999-01-01

Purpose:To investigate the fundus and fluorescein angiographic features in the patients with radiation retinopathy.Clinical Materials:Color fundus photography and/or fluorescein angiography from 13 patients with nasopharyngeal carcinomas received external beam radiation were retrospectively analyzed.Reslts:In this study,26 damaged eyes of 13 patients eveloped some degree of radiation retinopathy.The earliest and most common finding was macular microvascular changes (microaneurysms and/or telangiectasia),which was observed in 100%(26/26)of the eyes.Intraretinal hemorrhages,macular capillary nonperfusion,and macular edema were noted in 84%,50%,and 42% of the eyes,respectively.Conclusions:Radiation retinopathy is common after external beam radiation of nasopharyngeal carcinomas.The prominent changes include maular microvascular changes,intraretinal hemorrhages and macular capillary nonperfusion.

Lectin-like receptor for alpha 1-acid glycoprotein in the epithelium of the rat prostate gland and seminal vesicles

DEFF Research Database (Denmark)

Andersen, U O; Bøg-Hansen, T C; Kirkeby, S

1996-01-01

by mannose and N-Acetyl-D-glucosamine. RESULTS: In vitro the receptor was also inhibited by the steroid hormones cortisone, aldosterone, progesterone, and estradiol, but not by testosterone. A significant regional variation in the expression of AGP-lectin receptor and in the localization of AGP was seen...

Overexpression of Nictaba-Like Lectin Genes from Glycine max Confers Tolerance towards Pseudomonas syringae Infection, Aphid Infestation and Salt Stress in Transgenic Arabidopsis Plants

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Sofie Van Holle

2016-10-01

Full Text Available Plants have evolved a sophisticated immune system that allows them to recognize invading pathogens by specialized receptors. Carbohydrate-binding proteins or lectins are part of this immune system and especially the lectins that reside in the nucleocytoplasmic compartment are known to be implicated in biotic and abiotic stress responses. The class of Nictaba-like lectins (NLL groups all proteins with homology to the tobacco (Nicotiana tabacum lectin, known as a stress-inducible lectin. Here we focus on two Nictaba homologs from soybean (Glycine max, referred to as GmNLL1 and GmNLL2. Confocal laser scanning microscopy of fusion constructs with the green fluorescent protein either transiently expressed in Nicotiana benthamiana leaves or stably transformed in tobacco BY-2 suspension cells revealed a nucleocytoplasmic localization for the GmNLLs under study. RT-qPCR analysis of the transcript levels for the Nictaba-like lectins in soybean demonstrated that the genes are expressed in several tissues throughout the development of the plant. Furthermore, it was shown that salt treatment, Phytophthora sojae infection and Aphis glycines infestation trigger the expression of particular NLL genes. Stress experiments with Arabidopsis lines overexpressing the NLLs from soybean yielded an enhanced tolerance of the plant towards bacterial infection (Pseudomonas syringae, insect infestation (Myzus persicae and salinity. Our data showed a better performance of the transgenic lines compared to wild type plants, indicating that the NLLs from soybean are implicated in the stress response. These data can help to further elucidate the physiological importance of the Nictaba-like lectins from soybean, which can ultimately lead to the design of crop plants with a better tolerance to changing environmental conditions.

Human mannose-binding lectin inhibitor prevents Shiga toxin-induced renal injury

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Ozaki, Masayuki; Kang, Yulin; Tan, Ying Siow

2016-01-01

Hemolytic uremic syndrome caused by Shiga toxin-producing Escherichia coli (STEC HUS) is a worldwide endemic problem, and its pathophysiology is not fully elucidated. Here we tested whether the mannose-binding lectin (MBL2), an initiating factor of lectin complement pathway activation, plays a cr...

Evaluation of changes in serum chemistry in association with feed withdrawal or high dose oral gavage with Dextran Sodium Sulfate (DSS) induced gut leakage in broiler chickens

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Dextran sodium sulfate (DSS) has been shown to be effective at inducing enteric inflammation in broiler chickens, resulting in increased leakage of orally administered fluorescein isothiocyanate dextran to circulation. In a previous study, two doses of DSS (0.45g/dose) administered as oral gavage re...

Mucosal immunogenicity of plant lectins in mice

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Lavelle, E C; Grant, G; Pusztai, A; Pfüller, U; O’Hagan, D T

2000-01-01

The mucosal immunogenicity of a number of plant lectins with different sugar specificities was investigated in mice. Following intranasal (i.n.) or oral administration, the systemic and mucosal antibody responses elicited were compared with those induced by a potent mucosal immunogen (cholera toxin; CT) and a poorly immunogenic protein (ovalbumin; OVA). After three oral or i.n. doses of CT, high levels of specific serum antibodies were measured and specific IgA was detected in the serum, saliva, vaginal wash, nasal wash and gut wash of mice. Immunization with OVA elicited low titres of serum IgG but specific IgA was not detected in mucosal secretions. Both oral and i.n. delivery of all five plant lectins investigated [Viscum album (mistletoe lectin 1; ML‐1), Lycospersicum esculentum (tomato lectin; LEA), Phaseolus vulgaris (PHA), Triticum vulgaris (wheat germ agglutinin (WGA), Ulex europaeus I (UEA‐1)] stimulated the production of specific serum IgG and IgA antibody after three i.n. or oral doses. Immunization with ML‐1 induced high titres of serum IgG and IgA in addition to specific IgA in mucosal secretions. The response to orally delivered ML‐1 was comparable to that induced by CT, although a 10‐fold higher dose was administered. Immunization with LEA also induced high titres of serum IgG, particularly after i.n. delivery. Low specific IgA titres were also detected to LEA in mucosal secretions. Responses to PHA, WGA and UEA‐1 were measured at a relatively low level in the serum, and little or no specific mucosal IgA was detected. PMID:10651938

Mannan-binding lectin and mannan-binding lectin-associated serine protease 2 in acute pancreatitis

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Novovic, Srdan; Andersen, Anders; Ersbøll, Annette Kjær

2011-01-01

Complement activation may play a prominent role in acute pancreatitis (AP). Mannan-binding lectin (MBL) and MBL-associated serine protease 2 (MASP-2) participate in complement activation. The objective of the present study was to evaluate the role of MBL and MASP-2 as markers in AP with regard...

Differential binding properties of Gal/GalNAc specific lectins available for characterization of glycoreceptors.

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Wu, A M; Song, S C; Sugii, S; Herp, A

1997-01-01

Differentiating the binding properties of applied lectins should facilitate the selection of lectins for characterization of glycoreceptors on the cell surface. Based on the binding specificities studied by inhibition assays of lectin-glycan interactions, over twenty Gal and/or GalNAc specific lectins have been divided into eight groups according to their specificity for structural units (lectin determinants), which are the disaccharide as all or part of the determinants and of GalNAc alpha 1-->Ser (Thr) of the peptide chain. A scheme of codes for lectin determinants is illustrated as follows: (1) F (GalNAc alpha 1-->3GalNAc), Forssman specific disaccharide--Dolichos biflorus (DBL), Helix pomatia (HPL) and Wistaria floribunda (WFL) lectins. (2) A (GalNAc alpha 1-->3 Gal), blood group A specific disaccharide--Codium fragile subspecies tomentosoides (CFT), Soy bean (SBL), Vicia villosa-A4 (VVL-A4), and Wistaria floribunda (WFL) lectins. (3) Tn (GalNAc alpha 1-->Ser (Thr) of the protein core)--Vicia villosa B4 (VVL-B4), Salvia sclarea (SSL), Maclura pomifera (MPL), Bauhinia purpurea alba (BPL) and Artocarpus integrifolia (Jacalin, AIL). (4) T (Gal beta 1-->3GalNAc), the mucin type sugar sequences on the human erythrocyte membrane(T alpha), T antigen or the disaccharides at the terminal nonreducing end of gangliosides (T beta)--Peanut (PNA), Bauhinia purpurea alba (BPL), Maclura pomifera (MPL), Sophora japonica (SJL), Artocarpus lakoocha (Artocarpin) lectins and Abrus precatorius agglutinin (APA).(5) I and II (Gal beta 1-->3(4)GlcNAc)--the disaccharide residue at the nonreducing end of the carbohydrate chains derived from either N- or O-glycosidic linkage--Ricinus communis agglutinin (RCA1), Datura stramonium (TAL, Thorn apple), Erythrina cristagalli (ECL, Coral tree), and Geodia cydonium (GCL). (6) B (Gal alpha 1-->3Gal), human blood group B specific disaccharide--Griffonia(Banderiaea) simplicifolia B4 (GSI-B4). (7) E (Gal alpha 1-->4Gal), receptors for pathogenic E

Fluoride-induced modulation of ionic transport in asymmetric nanopores functionalized with "caged" fluorescein moieties.

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Ali, Mubarak; Ahmed, Ishtiaq; Ramirez, Patricio; Nasir, Saima; Cervera, Javier; Niemeyer, Christof M; Ensinger, Wolfgang

2016-04-28

We demonstrate experimentally and theoretically a nanofluidic fluoride sensing device based on a single conical pore functionalized with "caged" fluorescein moieties. The nanopore functionalization is based on an amine-terminated fluorescein whose phenolic hydroxyl groups are protected with tert-butyldiphenylsilyl (TBDPS) moieties. The protected fluorescein (Fcn-TBDPS-NH2) molecules are then immobilized on the nanopore surface via carbodiimide coupling chemistry. Exposure to fluoride ions removes the uncharged TBDPS moieties due to the fluoride-promoted cleavage of the silicon-oxygen bond, leading to the generation of negatively charged groups on the fluorescein moieties immobilized onto the pore surface. The asymmetrical distribution of these groups along the conical nanopore leads to the electrical rectification observed in the current-voltage (I-V) curve. On the contrary, other halides and anions are not able to induce any significant ionic rectification in the asymmetric pore. In each case, the success of the chemical functionalization and deprotection reactions is monitored through the changes observed in the I-V curves before and after the specified reaction step. The theoretical results based on the Nernst-Planck and Poisson equations further demonstrate the validity of an experimental approach to fluoride-induced modulation of nanopore current rectification behaviour.

Purification and characterization of a mucin specific mycelial lectin from Aspergillus gorakhpurensis: application for mitogenic and antimicrobial activity.

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Ram Sarup Singh

Full Text Available Lectins are carbohydrate binding proteins or glycoproteins that bind reversibly to specific carbohydrates present on the apposing cells, which are responsible for their ability to agglutinate red blood cells, lymphocytes, fibroblasts, etc. Interest in lectins has been intensified due to their carbohydrate specificity as they can be valuable reagents for the investigation of cell surface sugars, purification and characterization of glycoproteins. The present study reports the purification, characterization and evaluation of mitogenic and antimicrobial potential of a mycelial lectin from Aspergillus gorakhpurensis.Affinity chromatography on mucin-sepharose column was carried out for purification of Aspergillus gorakhpurensis lectin. The lectin was characterized for physico-chemical parameters. Mitogenic potential of the lectin was evaluated against splenocytes of Swiss albino mice by MTT assay. Antimicrobial activity of the purified lectin has also been evaluated by disc diffusion assay.Single-step affinity purification resulted in 18.6-fold purification of the mycelial lectin. The molecular mass of the lectin was found to be 70 kDa and it was composed of two subunits of 34.8 kDa as determined by gel filtration chromatography, SDS-PAGE and MALDI-TOF analysis. pH optima of the lectin was found to be 6.5-9.5, while optimum temperature for lectin activity was 20-30 °C. Lectin was stable within a pH range of 7.0-10.5 and showed fair thermostability. EDTA did not affect lectin activity whereas it was found susceptible to the denaturants tested. MTT assay revealed strong mitogenic potential of A. gorakhpurensis lectin at a concentration upto 150 µg/mL. Antimicrobial activity assay showed its potent antibacterial activity against Bacillus cereus, Staphylococcous aureus and Escherichia coli and marginal antifungal activity against Saccharomyces cerevisiae.This is the first report on the mitogenic and antimicrobial potential of Aspergillus gorakhpurensis

Purification and characterization of a mucin specific mycelial lectin from Aspergillus gorakhpurensis: application for mitogenic and antimicrobial activity.

Science.gov (United States)

Singh, Ram Sarup; Kaur, Hemant Preet; Singh, Jatinder

2014-01-01

Lectins are carbohydrate binding proteins or glycoproteins that bind reversibly to specific carbohydrates present on the apposing cells, which are responsible for their ability to agglutinate red blood cells, lymphocytes, fibroblasts, etc. Interest in lectins has been intensified due to their carbohydrate specificity as they can be valuable reagents for the investigation of cell surface sugars, purification and characterization of glycoproteins. The present study reports the purification, characterization and evaluation of mitogenic and antimicrobial potential of a mycelial lectin from Aspergillus gorakhpurensis. Affinity chromatography on mucin-sepharose column was carried out for purification of Aspergillus gorakhpurensis lectin. The lectin was characterized for physico-chemical parameters. Mitogenic potential of the lectin was evaluated against splenocytes of Swiss albino mice by MTT assay. Antimicrobial activity of the purified lectin has also been evaluated by disc diffusion assay. Single-step affinity purification resulted in 18.6-fold purification of the mycelial lectin. The molecular mass of the lectin was found to be 70 kDa and it was composed of two subunits of 34.8 kDa as determined by gel filtration chromatography, SDS-PAGE and MALDI-TOF analysis. pH optima of the lectin was found to be 6.5-9.5, while optimum temperature for lectin activity was 20-30 °C. Lectin was stable within a pH range of 7.0-10.5 and showed fair thermostability. EDTA did not affect lectin activity whereas it was found susceptible to the denaturants tested. MTT assay revealed strong mitogenic potential of A. gorakhpurensis lectin at a concentration upto 150 µg/mL. Antimicrobial activity assay showed its potent antibacterial activity against Bacillus cereus, Staphylococcous aureus and Escherichia coli and marginal antifungal activity against Saccharomyces cerevisiae. This is the first report on the mitogenic and antimicrobial potential of Aspergillus gorakhpurensis lectin. The

Antimicrobial lectin from Schinus terebinthifolius leaf.

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Gomes, F S; Procópio, T F; Napoleão, T H; Coelho, L C B B; Paiva, P M G

2013-03-01

Schinus terebinthifolius leaves are used for treating human diseases caused by micro-organisms. This work reports the isolation, characterization and antimicrobial activity of S. terebinthifolius leaf lectin (SteLL). The isolation procedure involved protein extraction with 0.15 mol l(-1) NaCl, filtration through activated charcoal and chromatography of the filtrate on a chitin column. SteLL is a 14-kDa glycopeptide with haemagglutinating activity that is inhibited by N-acetyl-glucosamine, not affected by ions (Ca(2+) and Mg(2+)) and stable upon heating (30-100 °C) as well as over the pH 5.0-8.0. The antimicrobial effect of SteLL was evaluated by determining the minimal inhibitory (MIC), bactericide (MBC) and fungicide (MFC) concentrations. Lectin was active against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella enteritidis and Staphylococcus aureus. Highest bacteriostatic and bactericide effects were detected for Salm. enteritidis (MIC: 0.45 μg ml(-1)) and Staph. aureus (MBC: 7.18 μg ml(-1)), respectively. SteLL impaired the growth (MIC: 6.5 μg ml(-1)) and survival (MFC: 26 μg ml(-1)) of Candida albicans. SteLL, a chitin-binding lectin, purified in milligram quantities, showed antimicrobial activity against medically important bacteria and fungi. SteLL can be considered as a new biomaterial for potential antimicrobial applications. © 2012 The Society for Applied Microbiology.

Analysis of chemical equilibrium of silicon-substituted fluorescein and its application to develop a scaffold for red fluorescent probes.

Science.gov (United States)

Hirabayashi, Kazuhisa; Hanaoka, Kenjiro; Takayanagi, Toshio; Toki, Yuko; Egawa, Takahiro; Kamiya, Mako; Komatsu, Toru; Ueno, Tasuku; Terai, Takuya; Yoshida, Kengo; Uchiyama, Masanobu; Nagano, Tetsuo; Urano, Yasuteru

2015-09-01

Fluorescein is a representative green fluorophore that has been widely used as a scaffold of practically useful green fluorescent probes. Here, we report synthesis and characterization of a silicon-substituted fluorescein, i.e., 2-COOH TokyoMagenta (2-COOH TM), which is a fluorescein analogue in which the O atom at the 10' position of the xanthene moiety of fluorescein is replaced with a Si atom. This fluorescein analogue forms a spirolactone ring via intramolecular nucleophilic attack of the carboxylic group in a pH-dependent manner. Consequently, 2-COOH TM exhibits characteristic large pH-dependent absorption and fluorescence spectral changes: (1) 2-COOH TM is colorless at acidic pH, whereas fluorescein retains observable absorption and fluorescence even at acidic pH, and the absorption maximum is also shifted; (2) the absorption spectral change occurs above pH 7.0 for 2-COOH TM and below pH 7.0 for fluorescein; (3) 2-COOH TM shows a much sharper pH response than fluorescein because of its pKa inversion, i.e., pKa1 > pKa2. These features are also different from those of a compound without the carboxylic group, 2-Me TokyoMagenta (2-Me TM). Analysis of the chemical equilibrium between pH 3.0 and 11.0 disclosed that 2-COOH TM favors the colorless and nonfluorescent lactone form, compared with fluorescein. Substitution of Cl atoms at the 4' and 5' positions of the xanthene moiety of 2-COOH TM to obtain 2-COOH DCTM shifted the equilibrium so that the new derivative exists predominantly in the strongly fluorescent open form at physiological pH (pH 7.4). To demonstrate the practical utility of 2-COOH DCTM as a novel scaffold for red fluorescent probes, we employed it to develop a probe for β-galactosidase.

High molecular weight lectin isolated from the mucus of the giant African snail Achatina fulica.

Science.gov (United States)

Ito, Shigeru; Shimizu, Masahiro; Nagatsuka, Maki; Kitajima, Seiji; Honda, Michiyo; Tsuchiya, Takahide; Kanzawa, Nobuyuki

2011-01-01

To understand better the host defense mechanisms of mollusks against pathogens, we examined the anti-microbial activity of mucus from the giant African snail Achatina fulica. Hemagglutination activity of the mucus secreted by the integument of snails inoculated with Escherichia coli was observed to increase and to cause hemagglutination of rabbit red blood cells. Purification of the snail mucus lectin by sequential column chromatography revealed that the relative molecular mass of the lectin was 350 kDa. The hemagglutination activity of the lectin was Ca(2+)-dependent and was inhibited by galactose. Growth arrest tests showed that the lectin did not inhibit bacterial growth, but did induce agglutination of gram-positive and gram-negative bacteria. Tissue distribution analyses using a polyclonal antibody revealed that the lectin was expressed in the tissues of the mantle collar. The lectin isolated from the mucus of the snail appeared to contribute to its innate immunity.

Uptake of magnetic nanoparticles into cells for cell tracking

International Nuclear Information System (INIS)

Becker, Christiane; Hodenius, Michael; Blendinger, Gitta; Sechi, Antonio; Hieronymus, Thomas; Mueller-Schulte, Detlef; Schmitz-Rode, Thomas; Zenke, Martin

2007-01-01

A challenge for future applications in nanotechnology is the functional integration of nano-sized materials into cellular structures. Here we investigated superparamagnetic Fe 3 O 4 iron oxide nanoparticles coated with a lipid bilayer for uptake into cells and for targeting subcellular compartments. It was found that magnetic nanoparticles (MNPs) are effectively taken up into cells and make cells acquire magnetic activity. Biotin-conjugated MNPs were further functionalized by binding of the fluorescent tag streptavidin-fluorescein isothiocyanate (FITC) and, following uptake into cells, shown to confer magnetic activity and fluorescence labeling. Such FITC-MNPs were localized in the lysosomal compartment of cells which suggests a receptor-mediated uptake mechanism

Cochlear microdialysis for quantification of dexamethasone and fluorescein entry into scala tympani during round window administration.

Science.gov (United States)

Hahn, Hartmut; Kammerer, Bernd; DiMauro, Andre; Salt, Alec N; Plontke, Stefan K

2006-02-01

Before new drugs for the treatment of inner ear disorders can be studied in controlled clinical trials, it is important that their pharmacokinetics be established in inner ear fluids. Microdialysis allows drug levels to be measured in perilymph without the volume disturbances and potential cerebrospinal fluid contamination associated with fluid sampling. The aims of this study were to show: (i) that despite low recovery rates from miniature dialysis probes, significant amounts of drug are removed from small fluid compartments, (ii) that dialysis sampling artifacts can be accounted for using computer simulations and (iii) that microdialysis allows quantification of the entry rates through the round window membrane (RWM) into scala tympani (ST). Initial experiments used microdialysis probes in small compartments in vitro containing sodium fluorescein. Stable concentrations were observed in large compartments (1000 microl) but significant concentration declines were observed in smaller compartments (100, 10 and 5.6 microl) comparable to the size of the inner ear. Computer simulations of these experiments closely approximated the experimental data. In in vivo experiments, sodium fluorescein 10 mg/ml and dexamethasone-dihydrogen-phosphate disodium salt 8 mg/ml were simultaneously applied to the RWM of guinea pigs. Perilymph concentration in the basal turn of ST was monitored using microdialysis. The fluorescein concentration reached after 200 min application (585+/-527 microg/ml) was approximately twice that of dexamethasone phosphate (291+/-369 microg/ml). Substantial variation in concentrations was found between animals by approximately a factor of 34 for fluorescein and at least 41 for dexamethasone phosphate. This is, to a large extent, thought to be the result of the RWM permeability varying in different animals. It was not caused by substance analysis variations, because two different analytic methods were used and the concentration ratio between the two

C-type lectins in immunity: recent developments

Science.gov (United States)

Dambuza, Ivy M; Brown, Gordon D

2015-01-01

C-type lectin receptors (CLRs) comprise a large superfamily of proteins, which recognise a diverse range of ligands, and are defined by the presence of at least one C-type lectin-like domain (CTLD). Of particular interest are the single extracellular CTLD-containing receptors of the ‘Dectin-1’ and ‘Dectin-2’ clusters, which associate with signalling adaptors or possess integral intracellular signalling domains. These CLRs have traditionally been associated with the recognition of fungi, but recent discoveries have revealed diverse and unexpected functions. In this review, we describe their newly identified roles in anti-microbial host defence, homeostasis, autoimmunity, allergy and their functions in the recognition and response to dead and cancerous cells. PMID:25553393

Fluorescein transport properties across artificial lipid membranes, Caco-2 cell monolayers and rat jejunum.

Science.gov (United States)

Berginc, Katja; Zakelj, Simon; Levstik, Lea; Ursic, Darko; Kristl, Albin

2007-05-01

Membrane transport characteristics of a paracellular permeability marker fluorescein were evaluated using artificial membrane, Caco-2 cell monolayers and rat jejunum, all mounted in side-by-side diffusion cells. Modified Ringer buffers with varied pH values were applied as incubation salines on both sides of artificial membrane, cell culture monolayers or rat jejunum. Passive transport according to pH partition theory was determined using all three permeability models. In addition to that, active transport of fluorescein in the M-S (mucosal-to-serosal) direction through rat jejunum was observed. The highest M-S P(app) values regarding the active transport through the rat jejunum were observed in incubation saline with pH 6.5. Fluorescein transport through the rat jejunum was inhibited by DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid) and alpha-CHC (alpha-cyano-4-hydroxycinnamic acid). Thus, we assume that two pH-dependent influx transporters could be involved in the fluorescein membrane transport through the intestinal (jejunal) epithelium. One is very likely an MCT (monocarboxylic acid cotransporter) isoform, inhibited by specific MCT inhibitor alpha-CHC, while the involvement of the second one with overlapping substrate/inhibitor specificities (most probably a member of the organic anion-transporting polypeptide family, inhibited at least partially by DIDS) could not be excluded.

Pseudomonas sax genes overcome aliphatic isothiocyanate-mediated non-host resistance in Arabidopsis

Science.gov (United States)

Jun Fan; Casey Crooks; Gary Creissen; Lionel Hill; Shirley Fairhurst; Peter Doerner; Chris Lamb

2011-01-01

Most plant-microbe interactions do not result in disease; natural products restrict non-host pathogens. We found that sulforaphane (4-methylsulfinylbutyl isothiocyanate), a natural product derived from aliphatic glucosinolates, inhibits growth in Arabidopsis of non-host Pseudomonas bacteria in planta. Multiple sax genes (saxCAB/F/D/G) were identified in Pseudomonas...

Fluorescein angiography and changes in aqueous humor protein after argon laser photomydriasis in rabbits

International Nuclear Information System (INIS)

Denffer, H. v.; Erhardt, W.; Neiss, A.

1979-01-01

In brown-eyed and blue-eyed rabbits, irises treated with argon laser photomydriasis (ALP) were studied by using fluorescein angiography and by evaluating the aqueous humor protein concentration. The following results were obtained. Immediately after ALP, a breakdown of the blood-aqueous barrier is demonstrated by a marked influx of fluorescein into the ciliary processes and into the anterior and posterior chambers. The dye flow into the aqueous humor decreases to normal values within 3 days. There is no fluorescein leakage from laser impacts themselves. Peripupillary capillary loops are permanently occluded, but in a few cases, recanalization occurs. Neovascularization did not occur during 56 days of observation. ALP initially leads to a six- to eightfold increase in normal aqueous humor protein concentration, which returns to normal values within 3 days. (orig./AJ) 891 AJ/orig.- 892 MKO [de

Rapid affinity-purification and physicochemical characterization of pumpkin (Cucurbita maxima) phloem exudate lectin.

Science.gov (United States)

Narahari, Akkaladevi; Swamy, Musti J

2010-04-21

The chito-oligosaccharide-specific lectin from pumpkin (Cucurbita maxima) phloem exudate has been purified to homogeneity by affinity chromatography on chitin. After SDS/PAGE in the presence of 2-mercaptoethanol, the pumpkin phloem lectin yielded a single band corresponding to a molecular mass of 23.7 kDa, whereas ESI-MS (electrospray ionization MS) gave the molecular masses of the subunit as 24645 Da. Analysis of the CD spectrum of the protein indicated that the secondary structure of the lectin consists of 9.7% alpha-helix, 35.8% beta-sheet, 22.5% beta-turn and 32.3% unordered structure. Saccharide binding did not significantly affect the secondary and tertiary structures of the protein. The haemagglutinating activity of pumpkin phloem lectin was mostly unaffected in the temperature range 4-70 degrees C, but a sharp decrease was seen between 75 and 85 degrees C. Differential scanning calorimetric and CD spectroscopic studies suggest that the lectin undergoes a co-operative thermal unfolding process centred at approx. 81.5 degrees C, indicating that it is a relatively stable protein.

The typing of Staphylococcus epidermidis by a lectin-binding assay

DEFF Research Database (Denmark)

Jarløv, J O; Hansen, J E; Rosdahl, V T

1992-01-01

A new typing method for Staphylococcus epidermidis was developed. Four biotinylated lectins--wheat germ agglutinin (WGA), soy bean agglutinin (SBA), lentil agglutinin (LCA) and Concanavalin A (ConA)--were added to immobilised whole cells of coagulase-negative staphylococci (CNS) in microtitration...... plates. The amount of bound lectin was measured by peroxidase-conjugated avidin followed by a peroxidase reaction. The method was compared to antibiotic-resistance analysis, phage typing, plasmid DNA profiles and slime production. A total of 113 isolates of CNS from 21 patients was investigated and 71...... strains of CNS, including 64 strains of S. epidermidis, were detected if all typing methods were taken into consideration. If only one typing method was used the highest discriminatory power among the S. epidermidis isolates was obtained with the lectin-binding assay which allowed 49 different strains...

Application of lectins to tumor imaging radiopharmaceuticals

International Nuclear Information System (INIS)

Kojima, Shuji; Jay, M.

1986-01-01

We investigated the in vitro binding of 125 I-lectins to Ehrlich ascites tumor (EAT) cells and in vivo uptake of 125 I-lectins in Ehrlich solid tumor (EST) bearing mice. In in vitro binding assays, phaseolus vulgaris agglutinin (PHA), pisum sativum agglutinin (PSA), and concanavalia agglutinin (Con A) showed a high affinity for EAT cells. The in vivo biodistribution of 125 I-lectins showed 125 I-PSA to be significantly taken up into EST tissues 24 h postinjection. After IV injection of 125 I-PSA, uptake of the radioactivity into the tumor tissues reached a maximum at 6 h, and thereafter decreased. Rapid disappearance of the radioactivity from blood and its excretion into kidney soon after injection of 125 I-PSA were observed. When compared with the biodistribution of 67 Ga-citrate in EST bearing mice 24 h postinjection, tumor to liver (T/B), tumor to muscle (T/M), and tumor to blood (T/B) ratios were superior for 125 I-PSA. At 6 h postinjection, the T/B-ratio of 125 I-PSA was 2.5, and this value may be sufficient to enable discernable diagnostic images. Our results suggest that PSA might be a useful tumor imaging radiopharmaceutical. (orig.)

A Crude 1-DNJ Extract from Home Made Bombyx Batryticatus Inhibits Diabetic Cardiomyopathy-Associated Fibrosis in db/db Mice and Reduces Protein N-Glycosylation Levels

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Qing Zhao

2018-06-01

Full Text Available The traditional Chinese drug Bombyx Batryticatus (BB, which is also named the white stiff silkworm, has been widely used in Chinese clinics for thousands of years. It is famous for its antispasmodic and blood circulation-promoting effects. Cardiomyocyte hypertrophy, interstitial cell hyperplasia, and myocardial fibrosis are closely related to the N-glycosylation of key proteins. To examine the alterations of N-glycosylation that occur in diabetic myocardium during the early stage of the disease, and to clarify the therapeutic effect of 1-Deoxynojirimycin (1-DNJ extracted from BB, we used the db/db (diabetic mouse model and an approach based on hydrophilic chromatography solid-phase extraction integrated with an liquid Chromatograph Mass Spectrometer (LC-MS identification strategy to perform a site-specific N-glycosylation analysis of left ventricular cardiomyocyte proteins. Advanced glycation end products (AGEs, hydroxyproline, connective tissue growth factor (CTGF, and other serum biochemical indicators were measured with enzyme-linked immunosorbent assays (ELISA. In addition, the α-1,6-fucosylation of N-glycans was profiled with lens culinaris agglutinin (LCA lectin blots and fluorescein isothiocyanate (FITC-labelled lectin affinity histochemistry. The results indicated that 1-DNJ administration obviously downregulated myocardium protein N-glycosylation in db/db mice. The expression levels of serum indicators and fibrosis-related cytokines were reduced significantly by 1-DNJ in a dose-dependent manner. The glycan α-1,6-fucosylation level of the db/db mouse myocardium was elevated, and the intervention effect of 1-DNJ administration on N-glycan α-1,6-fucosylation was significant. To verify this result, the well-known transforming growth factor-β (TGF-β/Smad2/3 pathway was selected, and core α-1,6-fucosylated TGF-β receptor II (TGFR-βII was analysed semi-quantitatively with western blotting. The result supported the conclusions obtained

BEL β-trefoil: a novel lectin with antineoplastic properties in king bolete (Boletus edulis) mushrooms.

Science.gov (United States)

Bovi, Michele; Cenci, Lucia; Perduca, Massimiliano; Capaldi, Stefano; Carrizo, Maria E; Civiero, Laura; Chiarelli, Laurent R; Galliano, Monica; Monaco, Hugo L

2013-05-01

A novel lectin was purified from the fruiting bodies of king bolete mushrooms (Boletus edulis, also called porcino, cep or penny bun). The lectin was structurally characterized i.e its amino acid sequence and three-dimensional structure were determined. The new protein is a homodimer and each protomer folds as β-trefoil domain and therefore we propose the name Boletus edulis lectin (BEL) β-trefoil to distinguish it from the other lectin that has been described in these mushrooms. The lectin has potent anti-proliferative effects on human cancer cells, which confers to it an interesting therapeutic potential as an antineoplastic agent. Several crystal forms of the apoprotein and of complexes with different carbohydrates were studied by X-ray diffraction. The structure of the apoprotein was solved at 1.12 Å resolution. The interaction of the lectin with lactose, galactose, N-acetylgalactosamine and T-antigen disaccharide, Galβ1-3GalNAc, was examined in detail. All the three potential binding sites present in the β-trefoil fold are occupied in at least one crystal form and are described in detail in this paper. No important conformational changes are observed in the lectin when comparing its co-crystals with carbohydrates with those of the ligand-free protein.

Mannan-binding lectin activates C3 and the

DEFF Research Database (Denmark)

Selander, B.; Martensson, U.; Weintraub, A.

2006-01-01

Lectin pathway activation of C3 is known to involve target recognition by mannan-binding lectin (MBL) or ficolins and generation of classical pathway C3 convertase via cleavage of C4 and C2 by MBL-associated serine protease 2 (MASP-2). We investigated C3 activation in C2-deficient human sera...... and in sera with other defined defects of complement to assess other mechanisms through which MBL might recruit complement. The capacity of serum to support C3 deposition was examined by ELISA using microtiter plates coated with O antigen-specific oligosaccharides derived from Salmonella typhimurium, S...

Isolation and characterization of a novel lectin from the mushroom Armillaria luteo-virens

International Nuclear Information System (INIS)

Feng, K.; Liu, Q.H.; Ng, T.B.; Liu, H.Z.; Li, J.Q.; Chen, G.; Sheng, H.Y.; Xie, Z.L.; Wang, H.X.

2006-01-01

From the dried fruiting bodies of the mushroom Armillaria luteo-virens, a dimeric lectin with a molecular mass of 29.4 kDa has been isolated. The purification procedure involved (NH 4 ) 2 SO 4 precipitation, ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of the lectin could not be inhibited by simple sugars but was inhibited by the polysaccharide inulin. The activity was stable up to 70 o C but was acid- and alkali-labile. Salts including FeCl 3 , AlCl 3 , and ZnCl 2 inhibited the activity whereas MgCl 2 , MnCl 2 , and CaCl 2 did not. The lectin stimulated mitogenic response of mouse splenocytes with the maximal response achieved by 1 μM lectin. Proliferation of tumor cells including MBL2 cells, HeLa cells, and L1210 cells was inhibited by the lectin with an IC 5 of 2.5, 5, and 10 μM, respectively. However, proliferation of HepG2 cells was not affected. The novel aspects of the isolated lectin include a novel N-terminal sequence, fair thermostability, acid stability, and alkali stability, together with potent mitogenic activity toward spleen cells and antiproliferative activity toward tumor cells

Anti-insect potential of lectins from Arisaema species towards Bactrocera cucurbitae.

Science.gov (United States)

Kaur, Manpreet; Singh, Kuljinder; Rup, Pushpinder J; Kamboj, Sukhdev Singh; Singh, Jatinder

2009-11-01

Bactrocera cucurbitae (Coquillett), also known as melon fruit fly, is one of the major insect pests of cucurbits in several parts of Asia, Africa and Pacific. In the present investigation, effect of lectins from two sources i.e. Arisaema intermedium Blume and Arisaema wallichianum Hook f. (Family-Araceae) has been studied on the development of second instar larvae of melon fruit fly. The lectins were incorporated separately in artificial diet at a concentration of 10 to 160 microg ml(-1) and fed adlibitum to the second instar larvae. Both the lectins were found to prolong the development period and significantly inhibited the pupation and emergence in a dose dependent manner. Total development period was found to be prolonged by 3.5 and 2.3 days in case of larvae fed on artificial diet containing A. intermedium (AIL) and A. wallichianum (AWL), respectively. LC50 values calculated on the basis of adult emergence came out to be 32.8 and 29 microg ml(-1) for AIL and AWL, respectively. Both the lectins tested, were found to increase the activity of esterases as larvae proceeded from 24 to 72 hr of treatment. The activity of acid phosphatase decreased significantly in larvae reared on diet containing LC50 of AIL, while in case of AWL significant decrease was observed only at 72 hr of treatment. Alkaline phosphatase activity decreased significantly on treatment with both of these lectins. These results showed that AIL and AWL have promising anti-insect potential. So, lectin gene/s from either of these species can be cloned and subsequently can be employed to develop transgenics to control melon fruit flies specifically and insect pests in general. This approach could be used as a part of Integrated pest management (IPM) strategies.

Structure of Dioclea virgata lectin: relations between carbohydrate binding site and nitric oxide production

International Nuclear Information System (INIS)

Delatorre, P.; Gadelha, C.A.A.; Santi-Gadelha, T.; Nobrega, R.B.; Rocha, B.A.M.; Nascimento, K.S.; Naganao, C.S.; Sampaio, A.H.; Cavada, B.S.; Pires, A.F.; Assreuy, A.M.S.

2012-01-01

Full text: Lectins are proteins/glycoproteins with at least one noncatalytic domain binding reversibly to specific monosaccharides or oligosaccharides. By binding to carbohydrate moieties on the cell surface, lectins participate in a range of cellular processes without changing the properties of the carbohydrates involved. The lectin of Dioclea virgata (DvirL), both native and complexed with X-man, was submitted to X-ray diffraction analysis and the crystal structure was compared to that of other Diocleinae lectins in order to better understand differences in biological proper- ties, especially with regard to the ability of lectins to induce nitric oxide (NO) production. The DvirL diffraction analysis revealed that both the native crystal and the X-Man-complexed form are orthorhombic and belong to space group I222. The cell parameters were: a=65.4 , b=86.6 and c=90.2 (native structure), and a=61.89 , b=87.67 and c=88.78 (X-Man-complexed structure). An association was observed between the volume of the carbohydrate recognition domain (CRD), the ability to induce NO production and the relative positions of Tyr12, Arg228 and Leu99. Thus, differences in biological activity induced by Diocleinae lectins are related to the configuration of amino acid residues in the carbohydrate binding site and to the structural conformation of subsequent regions capable of influencing site-ligand interactions. In conclusion, the ability of Diocleinae lectins to induce NO production depends on CRD configuration. (author)

Lectin Histochemical Study of Cell Surface Glycoconjugate in Gastric Carcinoma Using Helix Pomatia Agglutinin

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Mohammad Reza Arab

2010-07-01

Full Text Available "nAltered glycosylation of proteins in cancer cells is one of the main processes responsible for anaplasia, invasion and metastatic potential of neoplastic cells. Lectins are nonimmunogenetic compounds which specifically detect certain terminal sugars of glycoconjugates. The aim of the present study was to identify the N-acetylgalactosamine (GalNac containing glycoconjugates in cancer cells in all grades of gastric carcinoma. Paraffin blocks belong to 30 patients of gastric carcinoma (10 cases from each grade was collected from pathology file of Ali-Ebn-Abitaleb Hospital in Zahedan during 2005-2007. Prepared sections (5-7μm in thickness were stained by Alcian Blue, hematoxylin and eosin (H&E and helix pomatia agglutinin (HPA conjugated lectin. Lectin diluted up to 10μg/ml in PBS (0.1M, pH=6.8. Lectin reactivity was visualized by 0.03% diaminobenzidine (DAB solution. Sections were graded according to staining intensity to lectin (0-4+. Although there was some difference for lectin staining intensity between cancer cells in different grades of gastric carcinoma, statistical analysis showed that there was only a significant difference for cancer cells reactivity between histopathological grades of II and III. The pattern of reactivity to HPA lectin were also different from all histopathological grades. It seems that in cancer cells, the amount and distribution of GalNac containing glycoconjugate differ from neoplastic cells of different histopathological grades in gastric carcinoma.

Lectin Histochemical Study of Cell Surface Glycoconjugate in Gastric Carcinoma Using Helix Pomatia Agglutinin

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Mohammad Reza Arab

2010-08-01

Full Text Available Altered glycosylation of proteins in cancer cells is one of the main processes responsible for anaplasia, invasion and metastatic potential of neoplastic cells. Lectins are nonimmunogenetic compounds which specifically detect certain terminal sugars of glycoconjugates. The aim of the present study was to identify the N-acetylgalactosamine (GalNac containing glycoconjugates in cancer cells in all grades of gastric carcinoma. Paraffin blocks belong to 30 patients of gastric carcinoma (10 cases from each grade was collected from pathology file of Ali-Ebn-Abitaleb Hospital in Zahedan during 2005-2007. Prepared sections (5-7μm in thickness were stained by Alcian Blue, hematoxylin and eosin (H&E and helix pomatia agglutinin (HPA conjugated lectin. Lectin diluted up to 10μg/ml in PBS (0.1M, pH=6.8. Lectin reactivity was visualized by 0.03% diaminobenzidine (DAB solution. Sections were graded according to staining intensity to lectin (0-4+. Although there was some difference for lectin staining intensity between cancer cells in different grades of gastric carcinoma, statistical analysis showed that there was only a significant difference for cancer cells reactivity between histopathological grades of II and III. The pattern of reactivity to HPA lectin were also different from all histopathological grades. It seems that in cancer cells, the amount and distribution of GalNac containing glycoconjugate differ from neoplastic cells of different histopathological grades in gastric carcinoma.

Effect of Wasabi Component 6-(Methylsulfinylhexyl Isothiocyanate and Derivatives on Human Pancreatic Cancer Cells

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Yu-Jen Chen

2014-01-01

Full Text Available The naturally occurring compound 6-(methylsulfinylhexyl isothiocyanate (6-MITC was isolated from Wasabia japonica (Wasabi, a pungent spice used in Japanese food worldwide. The synthetic derivatives 6-(methylsulfenylhexyl isothiocyanate (I7447 and 6-(methylsulfonylhexyl isothiocyanate (I7557 are small molecule compounds derived from 6-MITC. This study aimed to evaluate the effect of these compounds on human pancreatic cancer cells. Human pancreatic cancer cell lines PANC-1 and BxPC-3 were used to perform an MTT assay for cell viability and Liu’s stain for morphological observation. The cell cycle was analyzed by DNA histogram. Aldehyde dehydrogenase (ALDH activity was used as a marker for cancer stem cells (CSC. Western blotting was performed for the expression of proteins related to CSC signaling. The results showed that compounds 6-MITC and I7557, but not I7447, inhibited viability of both PANC-1 and BxPC-3 cells. Morphological observation showed mitotic arrest and apoptosis in 6-MITC- and I7557-treated cells. These two compounds induced G2/M phase arrest and hypoploid population. Percentages of ALDH-positive PANC-1 cells were markedly reduced by 6-MITC and I7557 treatment. The expression of CSC signaling molecule SOX2, but not NOTCH1, ABCG2, Sonic hedgehog, or OCT4, was inhibited by 6-MITC and I7557. In conclusion, wasabi compounds 6-MITC and I7557 may possess activity against the growth and CSC phenotypes of human pancreatic cancer cells.

Lectins Labelled with Digoxin as a Novel Tool to Study Glycoconjugates

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Jerka Dumić

2002-01-01

Full Text Available In recent years it has become clear that carbohydrate portions of glycoconjugates are performing numerous vital physiological functions in higher organisms. However, since glycobiology is a relatively new science, and carbohydrate structures are highly complex, the continuous development of novel analytical techniques is necessary to support the process of understanding the intricate nature of glycoconjugate structure and function. The introduction of digoxin as a novel tag for labelling of lectins that are being used to analyse glycoconjugates in immunoassay-like techniques is described. Lectins labelled with digoxin have significant advantages over biotin- or digoxigenin-labelled lectins and will hopefully prove to be a useful addition to the repertoire of glycobiological tools.

Endophytic fungi from the roots of horseradish (Armoracia rusticana) and their interactions with the defensive metabolites of the glucosinolate - myrosinase - isothiocyanate system.

Science.gov (United States)

Szűcs, Zsolt; Plaszkó, Tamás; Cziáky, Zoltán; Kiss-Szikszai, Attila; Emri, Tamás; Bertóti, Regina; Sinka, László Tamás; Vasas, Gábor; Gonda, Sándor

2018-05-09

The health of plants is heavily influenced by the intensively researched plant microbiome. The microbiome has to cope with the plant's defensive secondary metabolites to survive and develop, but studies that describe this interaction are rare. In the current study, we describe interactions of endophytic fungi with a widely researched chemical defense system, the glucosinolate - myrosinase - isothiocyanate system. The antifungal isothiocyanates are also of special interest because of their beneficial effects on human consumers. Seven endophytic fungi were isolated from horseradish roots (Armoracia rusticana), from the genera Fusarium, Macrophomina, Setophoma, Paraphoma and Oidiodendron. LC-ESI-MS analysis of the horseradish extract incubated with these fungi showed that six of seven strains could decompose different classes of glucosinolates. Aliphatic, aromatic, thiomethylalkyl and indolic glucosinolates were decomposed by different strains at different rates. SPME-GC-MS measurements showed that two strains released significant amounts of allyl isothiocyanate into the surrounding air, but allyl nitrile was not detected. The LC-ESI-MS analysis of many strains' media showed the presence of allyl isothiocyanate - glutathione conjugate during the decomposition of sinigrin. Four endophytic strains also accepted sinigrin as the sole carbon source. Isothiocyanates inhibited the growth of fungi at various concentrations, phenylethyl isothiocyanate was more potent than allyl isothiocyanate (mean IC 50 was 2.30-fold lower). As a control group, ten soil fungi from the same soil were used. They decomposed glucosinolates with lower overall efficiency: six of ten strains had insignificant or weak activities and only three could use sinigrin as a carbon source. The soil fungi also showed lower AITC tolerance in the growth inhibition assay: the median IC 50 values were 0.1925 mM for endophytes and 0.0899 mM for soil fungi. The host's glucosinolates can be used by the tested

Differing lectin-binding patterns of malignant melanoma and nevocellular and Spitz nevi.

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Kohchiyama, A; Oka, D; Ueki, H

1987-01-01

The lectin-binding patterns of primary malignant melanoma, nevocellular nevus, and Spitz nevus were studied on formalin-fixed, paraffin-embedded sections using a series of biotinylated lectins--concanavalin A (ConA), Ricinus communis agglutinin-1 (RCA1), dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA), maclura pomifera agglutinin (MPA), peanut agglutinin (PNA), wheat germ agglutinin (WGA), and Ulex europeus agglutinin-1(UEA1)--and employing the avidin-biotin-peroxidase complex method. In nevocellular and Spitz nevi, all of the nevus cells were positively stained with ConA and RCA1. No positive staining was observed, however, with the other lectins and no change in binding patterns occurred following neuraminidase pretreatment. In malignant melanoma, all of the melanoma cells were positively stained with ConA and RCA1, and some were also stained with MPA, PNA, and WGA. In addition, DBA, SBA, MPA, PNA, and WGA labeled all of the melanoma cells after neuraminidase pretreatment. No positive staining was observed with UEA1 despite neuraminidase pretreatment. The present results showed that malignant melanoma and nevocellular and Spitz nevi have different lectin-binding patterns and different responses to neuraminidase pretreatment. We, therefore, believe that the lectin staining on paraffin-embedded sections can be a useful probe for the differentiation of these diseases.

Effects of environmental factors on C-type lectin recognition to zooxanthellae in the stony coral Pocillopora damicornis.

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Zhou, Zhi; Zhao, Shuimiao; Ni, Junyi; Su, Yilu; Wang, Lingui; Xu, Yanlai

2018-05-15

C-type lectin is a superfamily of Ca 2+ -dependent carbohydrate-recognition proteins that play significant roles in nonself-recognition and pathogen clearance. In the present study, a C-type lectin (PdC-Lectin) was chosen from stony coral Pocillopora damicornis to understand its recognition characteristics to zooxanthellae. PdC-Lectin protein contained a signal peptide and a carbohydrate-recognition domain with EPN motif in Ca 2+ -binding site 2. The PdC-Lectin recombinant protein was expressed and purified in vitro. The binding of PdC-Lectin protein to zooxanthellae was determined with western blotting method, and the bound protein to 10-10 5  cell mL -1 zooxanthellae was detectable in a concentration-dependent manner. Less PdC-Lectin protein binding to zooxanthellae was observed for the incubation at 36 °C than that at 26 °C. Furthermore, the PAMP recognition spectrum of PdC-Lectin protein was tested through surface plasmon resonance method, and it bound to LPS and Lipid A, but not to LTA, β-glucan, mannose or Poly (I:C). When PdC-Lectin protein was preincubated with LPS, there was less protein binding to zooxanthellae compared with that in non-preincubation group. These results collectively suggest that PdC-Lectin could recognize zooxanthellae, and the recognition could be repressed by high temperature and pathogenic bacteria, which would help to further understand the molecular mechanism of coral bleaching and the establishment of coral-zooxanthella symbiosis in the stony coral P. damicornis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sugar residues content and distribution in atrophic and hyperplastic postmenopausal human endometrium: lectin histochemistry

OpenAIRE

Gheri, G.; Gheri Bryk, S.; Taddei, G.; Moncini, D.; Noci, I.

1996-01-01

A lectin histochemical study was performed to investigate the glycoconjugate saccharidic moieties of the human postmenopausal endometrium (14 atrophic and 15 hyperplastic). For this purpose a battery of seven horseradish peroxidase-conjugated lectins (PNA, SBA, DBA, WGA, ConA, LTA and UEA I) was used. No differences in lectin binding between atrophic and hyperplastic endometria were observed. This investigation allowed us to provide a basic picture of the oligo...

Interactions between indole-3-acetic acid (IAA) with a lectin from Canavalia maritima seeds reveal a new function for lectins in plant physiology.

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Delatorre, Plinio; Silva-Filho, José Caetano; Rocha, Bruno Anderson Matias; Santi-Gadelha, Tatiane; da Nóbrega, Raphael Batista; Gadelha, Carlos Alberto Almeida; do Nascimento, Kyria Santiago; Nagano, Celso Shiniti; Sampaio, Alexandre Holanda; Cavada, Benildo Sousa

2013-09-01

Indole-3-acetic acid (IAA) bound is considered a storage molecule and is inactive. However, some studies have proposed an additional possible regulatory mechanism based on the ability of lectins to form complexes with IAA. We report the first crystal structure of ConM in complex with IAA at 2.15 Å resolution. Based on a tetrameric model of the complex, we hypothesize how the lectin controls the availability of IAA during the early seedling stages, indicating a possible new physiological role for these proteins. A free indole group is also bound to the protein. The ConM interaction with different forms of IAA is a strategy to render the phytohormone unavailable to the cell. Thus, this new physiological role proposed for legume lectins might be a novel mechanism by which IAA levels are decreased in addition to the destruction and formation of new complexes in the later stages of seed germination. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Lectin enhancement of the lipofection efficiency in human lung carcinoma cells.

Science.gov (United States)

Yanagihara, K; Cheng, P W

1999-10-18

Poor transfection efficiency of human lung carcinoma cells by lipofection begs further development of more efficient gene delivery strategies. The purpose of this study was to determine whether lectins can improve the lipofection efficiency in lung carcinoma cells. A549, Calu3, and H292 cells grown to 90% confluence were transfected for 18 h with a plasmid DNA containing a beta-galactosidase reporter gene (pCMVlacZ) using lipofectin plus a lectin as the vector. Ten different lectins, which exhibit a wide range of carbohydrate-binding specificities, were examined for their abilities to enhance the efficiency of lipofection. The transfected cells were assessed for transfection efficiency by beta-galactosidase activity (units/microg protein) and % blue cells following X-Gal stain. Lipofectin supplemented with Griffonia simplicifolia-I (GS-I) yields largest enhancement of the lipofection efficiency in A549 and Calu3 cells (5.3- and 28-fold, respectively). Maackia amurensis gives the largest enhancement (6.5-fold) of lipofection efficiency in H292 cells. The transfection efficiency correlates with the amounts of DNA delivered to the nucleus. Binding of FITC-labeled GS-I and the enhancement of the lipofection efficiency by GS-I were inhibited by alpha-methyl-D-galactopyranoside, indicating an alpha-galactoside-mediated gene transfer to lung carcinoma cells. We conclude that lectin-facilitated lipofection is an efficient gene delivery strategy. Employment of cell type-specific lectins may allow for efficient cell type-specific gene targeting.

The distribution of lectin receptor sites in human breast lesions.

Science.gov (United States)

Skutelsky, E; Hoenig, S; Griffel, B; Alroy, J

1988-08-01

Conflicting data regarding the status of A, B, H and T antigens in epithelium of normal, mastopathies, fibroadenomas and carcinomas of the breast stimulated us to re-examine the carbohydrate residues in these condition. Currently, we extended the number of carbohydrate residues studied by using ten different biotinylated lectins as probes and avidin-biotin-peroxidase complex (ABC) as a visualant. In addition, the pattern of lectin staining of cancerous cells in primary and metastatic sites was compared. In primary and metastatic breast carcinomas, lectin receptor sites were stained more intensely with Concanavalia ensiformi agglutinin (*Con A), Ricinus communis agglutinin-I (RCA-I) and wheat germ agglutinin (WGA), than in normal breast, in mastopathies or in fibroadenomas. Cryptic receptor sites for peanut agglutinin (PNA) were stained in all cases of breast carcinomas, while free PNA sites stained only in a few cases of well-differentiated carcinomas. Receptors sites for Ulex europaeus agglutinin-I (UEA-I) stained non-malignant epithelium of patients with blood group H but did not stain malignant cells. The results show significant differences in lectin-binding patterns and staining intensities between normal and non-malignant, and malignant epithelial breast cells. Furthermore, these results indicate that in malignant cells, there is an increased content of sialic acid-rich carbohydrates but not of asialylated glycoconjugates.

Comparison of the antimicrobial adhesion potential of human body fluid glycoconjugates using fucose-binding lectin (PA-IIL) of Pseudomonas aeruginosa and Ulex europaeus lectin (UEA-I).

Science.gov (United States)

Lerrer, Batia; Lesman-Movshovich, Efrat; Gilboa-Garber, Nechama

2005-09-01

Pseudomonas aeruginosa produces a fucose-binding lectin (PA-IIL) which strongly binds to human cells. This lectin was shown to be highly sensitive to inhibition by fucose-bearing human milk glycoproteins. Since the glycans of these glycoproteins mimic human cell receptors, they may function as decoys in blocking lectin-dependent pathogen adhesion to the host cells. Human saliva and seminal fluid also contain such compounds, and body fluids of individuals who are "secretors" express additional fucosylated (alpha 1,2) residues. The latter are selectively detected by Ulex europaeus lectin UEA-I. The aim of the present research was to compare the PA-IIL and UEA-I interactions with human salivas and seminal fluids of "secretors" and "nonsecretors" with those obtained with the respective milks. Using hemagglutination inhibition and Western blot analyses, we showed that PA-IIL interactions with the saliva and seminal fluid glycoproteins were somewhat weaker than those obtained with the milk and that "nonsecretor" body fluids were not less efficient than those of "secretors" in PA-IIL blocking. UEA-I, which interacted only with the "secretors" glycoproteins, was most sensitive to those of the seminal fluids.

Genomic sequence and organization of two members of a human lectin gene family

International Nuclear Information System (INIS)

Gitt, M.A.; Barondes, S.H.

1991-01-01

The authors have isolated and sequenced the genomic DNA encoding a human dimeric soluble lactose-binding lectin. The gene has four exons, and its upstream region contains sequences that suggest control by glucocorticoids, heat (environmental) shock, metals, and other factors. They have also isolated and sequenced three exons of the gene encoding another human putative lectin, the existence of which was first indicated by isolation of its cDNA. Comparisons suggest a general pattern of genomic organization of members of this lectin gene family

Mannose-binding lectin deficiency and acute exacerbations of chronic obstructive pulmonary disease

Directory of Open Access Journals (Sweden)

Woodruff PG

2012-11-01

Full Text Available Richard K Albert,1 John Connett,2 Jeffrey L Curtis,3,4 Fernando J Martinez,3 MeiLan K Han,3 Stephen C Lazarus,5 Prescott G Woodruff51Medicine Service, Denver Health and Department of Medicine, University of Colorado Denver, Denver, CO, 2Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, 3Pulmonary and Critical Care Medicine, Department of Medicine, University of Michigan, Ann Arbor, MI, 4Pulmonary and Critical Care Medicine, VA Medical Center, Ann Arbor, MI, 5Pulmonary and Critical Care Medicine, Department of Medicine, and Cardiovascular Research Institute, University of California, San Francisco, CA, USABackground: Mannose-binding lectin is a collectin involved in host defense against infection. Whether mannose-binding lectin deficiency is associated with acute exacerbations of chronic obstructive pulmonary disease is debated.Methods: Participants in a study designed to determine if azithromycin taken daily for one year decreased acute exacerbations had serum mannose-binding lectin concentrations measured at the time of enrollment.Results: Samples were obtained from 1037 subjects (91% in the trial. The prevalence of mannose-binding lectin deficiency ranged from 0.5% to 52.2%, depending on how deficiency was defined. No differences in the prevalence of deficiency were observed with respect to any demographic variable assessed, and no differences were observed in time to first exacerbation, rate of exacerbations, or percentage of subjects requiring hospitalization for exacerbations in those with deficiency versus those without, regardless of how deficiency was defined.Conclusion: In a large sample of subjects with chronic obstructive pulmonary disease selected for having an increased risk of experiencing an acute exacerbation of chronic obstructive pulmonary disease, only 1.9% had mannose-binding lectin concentrations below the normal range and we found no association between mannose-binding lectin

Effect of Algae and Plant Lectins on Planktonic Growth and Biofilm Formation in Clinically Relevant Bacteria and Yeasts

Directory of Open Access Journals (Sweden)

Mayron Alves Vasconcelos

2014-01-01

Full Text Available This study aimed to evaluate the abilities of plant and algae lectins to inhibit planktonic growth and biofilm formation in bacteria and yeasts. Initially, ten lectins were tested on Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella oxytoca, Pseudomonas aeruginosa, Candida albicans, and C. tropicalis at concentrations of 31.25 to 250 μg/mL. The lectins from Cratylia floribunda (CFL, Vatairea macrocarpa (VML, Bauhinia bauhinioides (BBL, Bryothamnion seaforthii (BSL, and Hypnea musciformis (HML showed activities against at least one microorganism. Biofilm formation in the presence of the lectins was also evaluated; after 24 h of incubation with the lectins, the biofilms were analyzed by quantifying the biomass (by crystal violet staining and by enumerating the viable cells (colony-forming units. The lectins reduced the biofilm biomass and/or the number of viable cells to differing degrees depending on the microorganism tested, demonstrating the different characteristics of the lectins. These findings indicate that the lectins tested in this study may be natural alternative antimicrobial agents; however, further studies are required to better elucidate the functional use of these proteins.

Isothiocyanates, Nitriles, and Epithionitriles from Glucosinolates Are Affected by Genotype and Developmental Stage in Brassica oleracea Varieties.

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Hanschen, Franziska S; Schreiner, Monika

2017-01-01

Vegetables of the Brassica oleracea group, such as broccoli, cauliflower, and cabbage, play an important role for glucosinolate consumption in the human diet. Upon maceration of the vegetable tissue, glucosinolates are degraded enzymatically to form volatile isothiocyanates, nitriles, and epithionitriles. However, only the uptake of isothiocyanates is linked to the cancer-preventive effects. Thus, it is of great interest to evaluate especially the isothiocyanate formation. Here, we studied the formation of glucosinolates and their respective hydrolysis products in sprouts and fully developed vegetable heads of different genotypes of the five B. oleracea varieties: broccoli, cauliflower as well as white, red, and savoy cabbages. Further, the effect of ontogeny (developmental stages) during the head development on the formation of glucosinolates and their respective hydrolysis products was evaluated at three different developmental stages (mini, fully developed, and over-mature head). Broccoli and red cabbage were mainly rich in 4-(methylsulfinyl)butyl glucosinolate (glucoraphanin), whereas cauliflower, savoy cabbage and white cabbage contained mainly 2-propenyl (sinigrin) and 3-(methylsulfinyl)propyl glucosinolate (glucoiberin). Upon hydrolysis, epithionitriles or nitriles were often observed to be the main hydrolysis products, with 1-cyano-2,3-epithiopropane being most abundant with up to 5.7 μmol/g fresh weight in white cabbage sprouts. Notably, sprouts often contained more than 10 times more glucosinolates or their hydrolysis products compared to fully developed vegetables. Moreover, during head development, both glucosinolate concentrations as well as hydrolysis product concentrations changed and mini heads contained the highest isothiocyanate concentrations. Thus, from a cancer-preventive point of view, consumption of mini heads of the B. oleracea varieties is recommended.

Lectin-Like Molecules of Lactobacillus rhamnosus GG Inhibit Pathogenic Escherichia coli and Salmonella Biofilm Formation.

Science.gov (United States)

Petrova, Mariya I; Imholz, Nicole C E; Verhoeven, Tine L A; Balzarini, Jan; Van Damme, Els J M; Schols, Dominique; Vanderleyden, Jos; Lebeer, Sarah

2016-01-01

Increased antibiotic resistance has catalyzed the research on new antibacterial molecules and alternative strategies, such as the application of beneficial bacteria. Since lectin molecules have unique sugar-recognizing capacities, and pathogens are often decorated with sugars that affect their survival and infectivity, we explored whether lectins from the probiotic strain Lactobacillus rhamnosus GG have antipathogenic properties. The genome sequence of L. rhamnosus GG was screened for the presence of lectin-like proteins. Two genes, LGG_RS02780 and LGG_RS02750, encoding for polypeptides with an N-terminal conserved L-type lectin domain were detected and designated Llp1 (lectin-like protein 1) and Llp2. The capacity of Llp1 and Llp2 to inhibit biofilm formation of various pathogens was investigated. Sugar specificity was determined by Sepharose beads assays and glycan array screening. The isolated lectin domains of Llp1 and Llp2 possess pronounced inhibitory activity against biofilm formation by various pathogens, including clinical Salmonella species and uropathogenic E. coli, with Llp2 being more active than Llp1. In addition, sugar binding assays with Llp1 and Llp2 indicate specificity for complex glycans. Both proteins are also involved in the adhesion capacity of L. rhamnosus GG to gastrointestinal and vaginal epithelial cells. Lectins isolated from or expressed by beneficial lactobacilli could be considered promising bio-active ingredients for improved prophylaxis of urogenital and gastrointestinal infections.

Bivalent Carbohydrate Binding Is Required for Biological Activity of Clitocybe nebularis Lectin (CNL), the N,N′-Diacetyllactosediamine (GalNAcβ1–4GlcNAc, LacdiNAc)-specific Lectin from Basidiomycete C. nebularis*

Science.gov (United States)

Pohleven, Jure; Renko, Miha; Magister, Špela; Smith, David F.; Künzler, Markus; Štrukelj, Borut; Turk, Dušan; Kos, Janko; Sabotič, Jerica

2012-01-01

Lectins are carbohydrate-binding proteins that exert their biological activity by binding to specific cell glycoreceptors. We have expressed CNL, a ricin B-like lectin from the basidiomycete Clitocybe nebularis in Escherichia coli. The recombinant lectin, rCNL, agglutinates human blood group A erythrocytes and is specific for the unique glycan N,N′-diacetyllactosediamine (GalNAcβ1–4GlcNAc, LacdiNAc) as demonstrated by glycan microarray analysis. We here describe the crystal structures of rCNL in complex with lactose and LacdiNAc, defining its interactions with the sugars. CNL is a homodimeric lectin, each of whose monomers consist of a single ricin B lectin domain with its β-trefoil fold and one carbohydrate-binding site. To study the mode of CNL action, a nonsugar-binding mutant and nondimerizing monovalent CNL mutants that retain carbohydrate-binding activity were prepared. rCNL and the mutants were examined for their biological activities against Jurkat human leukemic T cells and the hypersensitive nematode Caenorhabditis elegans mutant strain pmk-1. rCNL was toxic against both, although the mutants were inactive. Thus, the bivalent carbohydrate-binding property of homodimeric CNL is essential for its activity, providing one of the rare pieces of evidence that certain activities of lectins are associated with their multivalency. PMID:22298779

[Lectin-binding patterns and cell kinetics of head and neck squamous cell carcinomas].

Science.gov (United States)

Gotoh, T

1991-01-01

In order to elucidate the cell characteristics of head and neck squamous cell carcinomas, the cell kinetics and lectin binding patterns were compared with the histological classification and staging of the tumors, using surgically resected materials (maxillary sinus 10, oral cavity 21, pharynx 8, larynx 11). Eight biotinylated lectins (WGA, 1-PHA, ConA, UEA1, RCA1, SBA, DBA, PNA) were applied to the paraffin-embedded sections, and were visualized histochemically by the streptavidin-alkaline phosphatase method. The DNA contents of the isolated carcinoma cells obtained from the adjacent thick sections were evaluated using an epi-illumination cytofluorometer after propidium iodide staining. On lectin histochemistry, the binding pattern of WGA lectin was similar between carcinoma tissues and normal tissues, but the binding was more intense in well differentiated than less differentiated carcinomas. Lymph node metastasis was found to be related to the presence of cells with poor WGA-binding. In the binding patterns of the other lectins, RCA1, SBA and ConA were related to the differentiation of carcinomas, but they were not related to the TNM-classification. DNA cytofluorometry exhibited marked polyploidization, which progressed with the advancement of the clinical and pathological staging of carcinomas. However, the DNA ploidy pattern was not associated with the cell characteristics such as the degree of histological differentiation and the lectin-binding pattern, except that the appearance of aneuploidy had some relationship with the binding-patterns of UEA1 and 1-PHA.

[Separate factors influencing the interaction of carbohydrate- containing liposomes with galactose-specific lectins].

Science.gov (United States)

Dvorkin, V M; Vidershaĭn, G Ia

1984-11-01

Some natural (Gal-Cer, Lac-Cer, desyalylated gangliosides) and synthetic (HMGal) glycolipids differing in the length of the bridge linking the terminal galactose with the hydrophobic moiety were incorporated into the liposome membranes. The precipitation of the thus obtained vesicles induced by galactose-specific lectin RCA was studied. It was shown that when the amount of the glycolipids used for the incorporation into the liposomes (1 mol. %) was the same, the vesicles with HMGal or Gal-Cer incorporated into them did not precipitate in the presence of lectin, whereas the liposomes with incorporated Lac-Cer or desyalylated gangliosides did precipitate. It was thus concluded that in order for galactose-containing liposomes precipitation by lectin RCA1 to be induced, galactose should be separated from the liposome membrane with a distance not less than 7 A. The nature of lectin-induced nonspecific precipitation of ganglioside-containing liposomes, ganglioside mycelles and cardiolipin-lecithine liposomes containing lactosylceramide was investigated. Some nonspecific ionic interactions of negatively charged liposomes and ganglioside mycelles with lectin were observed, which disappeared with a rise in the NaCl concentration up to 150-200 mM.

Development of a novel fluorescent tag O-2-[aminoethyl]fluorescein for the electrophoretic separation of oligosaccharides

International Nuclear Information System (INIS)

Kazarian, Artaches A.; Smith, Jason A.; Hilder, Emily F.; Breadmore, Michael C.; Quirino, Joselito P.; Suttil, James

2010-01-01

This study describes the development of a novel fluorescent tag, O-2-[aminoethyl]fluorescein, for the separation of sugars by capillary electrophoresis with fluorescence detection using an argon ion laser. The tag was synthesised using three consecutive steps namely: esterification, alkylation and hydrolysis, specifically designed to offer a flexible way in which to make an assortment of fluorescent tags from cheap and readily available starting reagents (typically less than $1 per g of fluorescent tag). Via this flexible synthetic pathway, O-2-[aminoethyl]fluorescein was designed and synthesised with a spacer group to lower steric effects between the fluorescein backbone and the reducing end of the carbohydrate which were anticipated to improve the reactivity of the tag. The newly synthesised tag, O-2-[aminoethyl]fluorescein was evaluated against structurally similar commercial fluorescent motifs namely fluorescent 5-aminomethylfluorescein and non-fluorescent 5-aminofluorescein. Kinetic studies indicated that O-2-[aminoethyl]fluorescein showed similar labeling efficiencies as 5-aminomethylfluorescein, but were achieved in only 30 min, supporting the notion of improved reactivity of the spacer group. The sensitivity of O-2-[aminoethyl]fluorescein was evaluated using maltoheptaose with a detection limit of 1 nM obtained, which was slightly higher than that of 0.3 nM obtained with 5-aminomethylfluorescein, and was due to its lower quantum yield (0.24) when conjugated to the sugar. The separation performance of the tag was also benchmarked with the two commercial reagents using a range of corn syrup oligosaccharides, from 4 to 10 glucose units, typically found in rice starch. Separations were performed using an electrolyte containing 100 mM boric acid, tris at pH 8.65 as background electrolyte, 30 kV applied voltage, 50 μm I.D. x 40 cm (30 cm effective length) capillary. The novel tag showed better resolution of small oligosaccharides, G3 and G4, than the other two

Optimizing isothiocyanate formation during enzymatic glucosinolate breakdown by adjusting pH value, temperature and dilution in Brassica vegetables and Arabidopsis thaliana

OpenAIRE

Hanschen, Franziska S.; Klopsch, Rebecca; Oliviero, Teresa; Schreiner, Monika; Verkerk, Ruud; Dekker, Matthijs

2017-01-01

Consumption of glucosinolate-rich Brassicales vegetables is associated with a decreased risk of cancer with enzymatic hydrolysis of glucosinolates playing a key role. However, formation of health-promoting isothiocyanates is inhibited by the epithiospecifier protein in favour of nitriles and epithionitriles. Domestic processing conditions, such as changes in pH value, temperature or dilution, might also affect isothiocyanate formation. Therefore, the influences of these three factors were eva...

Genetics Home Reference: mannose-binding lectin deficiency

Science.gov (United States)

... and Caregivers: Complement System Nobelprize.org: The Immune System - In More Detail Patient ... Sources for This Page Arora M, Munoz E, Tenner AJ. Identification of a site on mannan-binding lectin critical ...

Comparisons of labeling efficiency, biological activity and biodistribution among 125I, 67Ga-DTPA- and 67Ga-DFO-lectins

International Nuclear Information System (INIS)

Kojima, Shuji; Jay, M.

1987-01-01

The labeling efficiency, biological activity and biodistribution of 125 I labeled and 67 Ga chelating agent conjugated lectins were investigated. Pisum sativum agglutinin (PSA) and Lens culinaris agglutinin (LCH) were efficiently labeled with 67 Ga using bifunctional chelating agents such as diethylenetriaminepentaacetic acid (DTPA) and deferoxamine (DFO), whereas labeling with 125 I was significantly less efficient. The agglutinating activity of these lectins towards Ehrlich ascites tumor (EAT) cells was retained on conjugation with DFO, but not with DTPA. The in vitro binding ratio of 67 Ga-DFO-lectins for EAT cells was almost the same as that of 125 I-lectins. However, the value was significantly decreased in the case of 67 Ga-DTPA-lectins. In the biodistribution study of radiolabeled lectins in Ehrlich solid tumor (EST) bearing mice, the accumulation of radioactivity in tumor tissue was very much less with 67 Ga-DTPA-lectins than with 125 I-lectins. However, the concentration was significantly elevated in the case of 67 Ga-DFO-lectins. While, these lectins accumulated in liver, spleen, lung, and kidney to a greater extent than 67 Ga citrate, the tumor to organ ratios became very low. These low tumor to organ ratios, in contrast to 67 Ga citrate, will certainly inhibit the tumor delineation, and therefore it seems that in spite of a high accumulation ratio of 67 Ga-DFO-lectins in tumor tissue, these agents are not useful in tumor detection. (orig.)

Role of bone marrow-derived stem cells, renal progenitor cells and ...

African Journals Online (AJOL)

Hayam Abdel Meguid El Aggan

2013-04-06

Apr 6, 2013 ... renal blood flow; MoAbs, monoclonal antibodies; PE, phycoerythrin;. FITC, fluorescein isothiocyanate. ... Detection of HSCs and MSCs in the peripheral blood using flow cytometry via detection of CD34, CD45, CD117 and ..... the peripheral capillary loops in 25–50% (cg2). Six biopsies showed an increase ...

Facile synthesis of aliphatic isothiocyanates and thioureas on solid phase using peptide coupling reagents

DEFF Research Database (Denmark)

Boas, Ulrik; Andersen, Heidi Gertz; Christensen, Jørn B.

2004-01-01

Peptide coupling reagents can be used as versatile reagents for the formation of aliphatic isothiocyanates and thioureas on solid phase from the corresponding solid-phase anchored aliphatic primary amines. The formation of the thioureas is fast and highly chemoselective, and proceeds via formatio...

A new efficient synthesis of isothiocyanates from amines using di-tert-butyl dicarbonate

DEFF Research Database (Denmark)

Munch, Henrik; Hansen, Jon S.; Pittelkow, Michael

2008-01-01

Alkyl and aryl amines are converted smoothly to the corresponding isothiocyanates via the dithiocarbamates in good to excellent yields using di-tert-butyl dicarbonate (Boc(2)O) and 1-3 mol% of DMAP or DABCO as catalyst. As most of the byproducts are volatile, the work-up involves simple evaporation...

Fabrication and characterization of vacuum deposited fluorescein thin films

Energy Technology Data Exchange (ETDEWEB)

Jalkanen, Pasi, E-mail: pasi.jalkanen@gmail.co [University of Jyvaeskylae, Department of Physics, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Kulju, Sampo, E-mail: sampo.j.kulju@jyu.f [University of Jyvaeskylae, Department of Physics, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Arutyunov, Konstantin, E-mail: konstantin.arutyunov@jyu.f [University of Jyvaeskylae, Department of Physics, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Antila, Liisa, E-mail: liisa.j.antila@jyu.f [University of Jyvaeskylae, Department of Chemistry, Nanoscience center (NSC) P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Myllyperkioe, Pasi, E-mail: pasi.myllyperkio@jyu.f [University of Jyvaeskylae, Department of Chemistry, Nanoscience center (NSC) P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Ihalainen, Teemu, E-mail: teemu.o.ihalainen@jyu.f [University of Jyvaeskylae, Department of Biology, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Kaeaeriaeinen, Tommi, E-mail: tommi.kaariainen@lut.f [Lappeenranta University of Technology, ASTRal, P.O. Box 181, FI-50101 Mikkeli (Finland); Kaeaeriaeinen, Marja-Leena, E-mail: marja-leena.kaariainen@lut.f [Lappeenranta University of Technology, ASTRal, P.O. Box 181, FI-50101 Mikkeli (Finland); Korppi-Tommola, Jouko, E-mail: jouko.korppi-tommola@jyu.f [University of Jyvaeskylae, Department of Biology, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland)

2011-03-31

Simple vacuum evaporation technique for deposition of dyes on various solid surfaces has been developed. The method is compatible with conventional solvent-free nanofabrication processing enabling fabrication of nanoscale optoelectronic devices. Thin films of fluorescein were deposited on glass, fluorine-tin-oxide (FTO) coated glass with and without atomically layer deposited (ALD) nanocrystalline 20 nm thick anatase TiO{sub 2} coating. Surface topology, absorption and emission spectra of the films depend on their thickness and the material of supporting substrate. On a smooth glass surface the dye initially forms islands before merging into a uniform layer after 5 to 10 monolayers. On FTO covered glass the absorption spectra are similar to fluorescein solution in ethanol. Absorption spectra on ALD-TiO{sub 2} is red shifted compared to the film deposited on bare FTO. The corresponding emission spectra at {lambda} = 458 nm excitation show various thickness and substrate dependent features, while the emission of films deposited on TiO{sub 2} is quenched due to the effective electron transfer to the semiconductor conduction band.

Dually supplied T-junctions in arteriolo-arteriolar anastomosis in mice: key to local hemodynamic homeostasis in normal and ischemic states?

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Toriumi, Haruki; Tatarishvili, Jemal; Tomita, Minoru; Tomita, Yutaka; Unekawa, Miyuki; Suzuki, Norihiro

2009-10-01

The functional role of arteriolo-arteriolar anastomosis (AAA) between the middle cerebral artery (MCA) and anterior cerebral artery in local hemodynamics is unknown, and was investigated here. Blood flow in AAAs was examined using fluorescein isothiocyanate-labeled red blood cells (RBCs) as a flow indicator in 16 anesthetized C57BL/6J mice before and after MCA occlusion up to 7 experimental days. We observed paradoxical flow in AAAs; labeled RBCs entered from both the MCA and anterior cerebral artery sides and the opposing flows met at a branching T-junction, where the flows combined and passed into a penetrating arteriole. The dually fed T-junction was not fixed in position, but functionally jumped to adjacent T-junctions in response to changing hemodynamic conditions. On MCA occlusion, RBC flow from the MCA side immediately stopped. After a period of "hesitation," blood started to move retrogradely in one of the MCA branches toward the MCA stem. The retrograde blood flow was statistically significantly (P<0.05), serving to feed blood to other MCA branches after a lag period. In capillaries, MCA occlusion induced immediate RBC disappearance in the ischemic core and to a lesser extent in the marginal zone near AAAs. At day 3 after ischemia, we recognized the beginning of remodeling with angiogenesis centering on AAAs. AAAs appear to play a key role in local hemodynamic homeostasis, both in the normal state and in the development of collateral channels and revascularization during ischemia.

A putative carbohydrate-binding domain of the lactose-binding Cytisus sessilifolius anti-H(O) lectin has a similar amino acid sequence to that of the L-fucose-binding Ulex europaeus anti-H(O) lectin.

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Konami, Y; Yamamoto, K; Osawa, T; Irimura, T

1995-04-01

The complete amino acid sequence of a lactose-binding Cytisus sessilifolius anti-H(O) lectin II (CSA-II) was determined using a protein sequencer. After digestion of CSA-II with endoproteinase Lys-C or Asp-N, the resulting peptides were purified by reversed-phase high performance liquid chromatography (HPLC) and then subjected to sequence analysis. Comparison of the complete amino acid sequence of CSA-II with the sequences of other leguminous seed lectins revealed regions of extensive homology. The amino acid sequence of a putative carbohydrate-binding domain of CSA-II was found to be similar to those of several anti-H(O) leguminous lectins, especially to that of the L-fucose-binding Ulex europaeus lectin I (UEA-I).

[Effect of Azospirillum lectins on the Activity of Proteolytic Enzymes and Their Inhibitors in Wheat Seedling Roots].

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Alen'kina, S A; Nikitina, V E

2015-01-01

The lectins of associative nitrogen-fixing strains Azospirillum brasilense Sp7 and Sp245 were shown to exerte a multidirectional effect on the activity of acidic (pH 3.5), neutral (6.8), and alkaline (pH 7.8) proteinases. The lectin of the epiphytic A. brasilense Sp7 decreased proteolytic activity at all pH values, whereas the lectin of the endophytic A. brasilense Sp245 activated neutral and alkaline proteinases, while not affecting the alkaline ones. Experiments with protease inhibitors made it possible to conclude that the lectins of the studied A. brasilense strains alter the ratio between the activities of different protease types in germinating seeds. The activity of trypsin inhibitors in wheat seedling roots was found to increase in the presence of the lectins. Our results indicate a broader spectrum of effects of azospirilla lectins on the host plant organism.

Teaching Old Dyes New Tricks: Biological Probes Built from Fluoresceins and Rhodamines.

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Lavis, Luke D

2017-06-20

Small-molecule fluorophores, such as fluorescein and rhodamine derivatives, are critical tools in modern biochemical and biological research. The field of chemical dyes is old; colored molecules were first discovered in the 1800s, and the fluorescein and rhodamine scaffolds have been known for over a century. Nevertheless, there has been a renaissance in using these dyes to create tools for biochemistry and biology. The application of modern chemistry, biochemistry, molecular genetics, and optical physics to these old structures enables and drives the development of novel, sophisticated fluorescent dyes. This critical review focuses on an important example of chemical biology-the melding of old and new chemical knowledge-leading to useful molecules for advanced biochemical and biological experiments.

Sugar-Binding Profiles of Chitin-Binding Lectins from the Hevein Family: A Comprehensive Study

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Yoko Itakura

2017-05-01

Full Text Available Chitin-binding lectins form the hevein family in plants, which are defined by the presence of single or multiple structurally conserved GlcNAc (N-acetylglucosamine-binding domains. Although they have been used as probes for chito-oligosaccharides, their detailed specificities remain to be investigated. In this study, we analyzed six chitin-binding lectins, DSA, LEL, PWM, STL, UDA, and WGA, by quantitative frontal affinity chromatography. Some novel features were evident: WGA showed almost comparable affinity for pyridylaminated chitotriose and chitotetraose, while LEL and UDA showed much weaker affinity, and DSA, PWM, and STL had no substantial affinity for the former. WGA showed selective affinity for hybrid-type N-glycans harboring a bisecting GlcNAc residue. UDA showed extensive binding to high-mannose type N-glycans, with affinity increasing with the number of Man residues. DSA showed the highest affinity for highly branched N-glycans consisting of type II LacNAc (N-acetyllactosamine. Further, multivalent features of these lectins were investigated by using glycoconjugate and lectin microarrays. The lectins showed substantial binding to immobilized LacNAc as well as chito-oligosaccharides, although the extents to which they bound varied among them. WGA showed strong binding to heavily sialylated glycoproteins. The above observations will help interpret lectin-glycoprotein interactions in histochemical studies and glyco-biomarker investigations.

Lectin-Like Molecules of Lactobacillus rhamnosus GG Inhibit Pathogenic Escherichia coli and Salmonella Biofilm Formation

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Petrova, Mariya I.; Imholz, Nicole C. E.; Verhoeven, Tine L. A.; Balzarini, Jan; Van Damme, Els J. M.; Schols, Dominique; Vanderleyden, Jos; Lebeer, Sarah

2016-01-01

Objectives Increased antibiotic resistance has catalyzed the research on new antibacterial molecules and alternative strategies, such as the application of beneficial bacteria. Since lectin molecules have unique sugar-recognizing capacities, and pathogens are often decorated with sugars that affect their survival and infectivity, we explored whether lectins from the probiotic strain Lactobacillus rhamnosus GG have antipathogenic properties. Methods The genome sequence of L. rhamnosus GG was screened for the presence of lectin-like proteins. Two genes, LGG_RS02780 and LGG_RS02750, encoding for polypeptides with an N-terminal conserved L-type lectin domain were detected and designated Llp1 (lectin-like protein 1) and Llp2. The capacity of Llp1 and Llp2 to inhibit biofilm formation of various pathogens was investigated. Sugar specificity was determined by Sepharose beads assays and glycan array screening. Results The isolated lectin domains of Llp1 and Llp2 possess pronounced inhibitory activity against biofilm formation by various pathogens, including clinical Salmonella species and uropathogenic E. coli, with Llp2 being more active than Llp1. In addition, sugar binding assays with Llp1 and Llp2 indicate specificity for complex glycans. Both proteins are also involved in the adhesion capacity of L. rhamnosus GG to gastrointestinal and vaginal epithelial cells. Conclusions Lectins isolated from or expressed by beneficial lactobacilli could be considered promising bio-active ingredients for improved prophylaxis of urogenital and gastrointestinal infections. PMID:27537843

Carbohydrate specificity of lectin, purified from the fruiting bodies of Mycena pura /Fr./ Kumm. and its use in histochemical investigation

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Ambarova N. O.

2009-12-01

Full Text Available Aim. The purpose of this investigation was to research carbohydrate specificity of a new lectin from fruiting body of Mycena pura and possibilities of its application in histochemical studies. Methods. The lectin has been purified by affinity chromatography on «îvomucine». The lectin carbohydrate specificity has been determined by a reaction of inhibiting haemagglutination by haptens. Histological materials were fixed in 4 % neutral formalin solution. Alkaline phosphatase was revealed in the cryostat unfixed microscopical sections. Results. The lectin yield from fresh fruit bodies of raw material was 9 mg/kg. Mol. mass of the lectin is 40 kDa. The lectin poorly interacted with D-glucose and D-mannose in contrast to lectins from Pisum sativum and Leucojum vernum. The peculiarity of this lectin is its strong interaction with alkaline phosphatase, the highest among twenty tested lectins. However, the receptors for Mycena lectin binding in mammalian tissues are not limited by this enzyme being presented also by glycoconjugates of another structure, as it was shown for fetus calf small intestine and kidney of rat. Conclusions. An important role in the lectin interaction with glycoproteins probably belongs to the disaccharide links of GlcNAcb(1-2Mana(1-6 or GlcNAcb(1- 2Mana(1-2, which not necessarily are terminal

Momordica charantia seed lectin: toxicity, bacterial agglutination and antitumor properties.

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Kabir, Syed Rashel; Nabi, Md Mahamodun; Nurujjaman, Md; Abu Reza, Md; Alam, A H M Khurshid; Uz Zaman, Rokon; Khalid-Bin-Ferdaus, Khandaker Md; Amin, Ruhul; Khan, Md Masudul Hasan; Hossain, Md Anowar; Uddin, Md Salim; Mahmud, Zahid Hayat

2015-03-01

In last three decades, several studies were carried out on the D-galactose-specific lectin of Momordica charantia seeds (MCL). In the present study, in vitro growth inhibition (8-23 %) at different concentrations (6-24 μg/ml) of MCL was observed against Ehrlich ascites carcinoma (EAC) cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. MCL also showed 28, 45, and 75 % growth inhibitions against EAC cells when administered 1.2, 2.0, and 2.8 mg/kg/day (i.p.), respectively for five consequent days in vivo in mice. After lectin treatment, the level of red blood cell and hemoglobin was increased significantly with the decrease of white blood cell and maintained the normal level when compared with EAC-bearing control and normal mice without EAC cells. Although MCL caused cell cycle arrest at G0/G1 phase of EAC cells, any irregular shape or apoptotic morphological alterations in the lectin-treated EAC cells was not observed by an optical and fluorescence microscope. Lectin showed toxicity against brine shrimp nauplii with an LC50 value of 49.7 μg/ml. Four out of seven pathogenic bacteria were agglutinated by MCL in the absence of inhibitory sugar D-lactose/D-galactose. In conclusion, MCL showed strong cytotoxic effect and therefore can be used as a potent anticancer chemotherapeutic agent.

New crystal forms of Diocleinae lectins in the presence of different dimannosides

International Nuclear Information System (INIS)

Moreno, Frederico Bruno Mendes Batista; Bezerra, Gustavo Arruda; Oliveira, Taianá Maia de; Souza, Emmanuel Prata de; Rocha, Bruno Anderson Matias da; Benevides, Raquel Guimarães; Delatorre, Plínio; Cavada, Benildo Sousa; Azevedo, Walter Filgueira Jr de

2006-01-01

The crystallization and preliminary X-ray data of Canavalia gladiata lectin (CGL) and C. maritima lectin (CML) complexed with Man(α1-2)Man(α1)OMe, Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe in two crystal forms [the complexes with Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe crystallized in space group P3 2 and those with Man(α1-2)Man(α1)OMe crystallized in space group I222], which differed from those of the native proteins (P2 1 2 1 2 for CML and C222 for CGL), are reported. Studying the interactions between lectins and sugars is important in order to explain the differences observed in the biological activities presented by the highly similar proteins of the Diocleinae subtribe. Here, the crystallization and preliminary X-ray data of Canavalia gladiata lectin (CGL) and C. maritima lectin (CML) complexed with Man(α1-2)Man(α1)OMe, Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe in two crystal forms [the complexes with Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe crystallized in space group P3 2 and those with Man(α1-2)Man(α1)OMe crystallized in space group I222], which differed from those of the native proteins (P2 1 2 1 2 for CML and C222 for CGL), are reported. The crystal complexes of ConA-like lectins with Man(α1-4)Man(α1)OMe are reported here for the first time

Tear fluid analysis in patients with primary Sjögren's syndrome using lectin probes

DEFF Research Database (Denmark)

Bjerrum, Kirsten Birgitte

1999-01-01

Ophthalmology, Sjögren's syndrome, dry eye, keratoconjunctivitis sicca, glycoprotein, mucus, lectins, Coomassie, electrophoresis, SDS-PAGE-blotting......Ophthalmology, Sjögren's syndrome, dry eye, keratoconjunctivitis sicca, glycoprotein, mucus, lectins, Coomassie, electrophoresis, SDS-PAGE-blotting...

Structure prediction and functional analysis of a non-permutated lectin from Dioclea grandiflora.

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de Sousa, Bruno Lopes; Nagano, Celso Shiniti; Simões, Rafael da Conceição; Silva-Filho, José Caetano; Cunha, Rodrigo Maranguape da Silva; Cajazeiras, João Batista; do Nascimento, Kyria Santiago; Cavada, Benildo Sousa

2016-12-01

Legume lectins have been widely studied and applied for many purposes in the last few decades, but many of their physiological aspects remain elusive. The Diocleinae legume subtribe, which includes intensively explored lectins, such as ConA, presents an unusual and extensive post-translational process which results in minor alterations in protein structure, in turn making its function elusive. Despite previous reports about Diocleinae precursor activity, no structural or functional analyses have ever been carried out to understand the impacts of post-translational processing relative to lectin structure and binding specificity. Here we analyzed the functionality of a non glycosylated, recombinantly expressed lectin precursor from Dioclea grandiflora through inhibition assays, corroborating the experimental data with structural information generated by molecular modeling, docking calculations and molecular dynamics simulations. We demonstrate that Diocleinae precursors are active and share the same carbohydrate specificity as mature lectins. At the same time, however, subtle structural alterations were detected and mostly result in an "incomplete" functionality of the precursor, as consequence of an immature binding site and an unstructured tetramer interface, affecting carbohydrate binding and oligomer formation, respectively. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Lectin binding patterns and immunohistochemical antigen detection ...

African Journals Online (AJOL)

Ibrahim Eldaghayes

2018-02-09

Feb 9, 2018 ... placenta and lungs of Brucella abortus-bovine infected fetuses. María Andrea ... The present lectin histochemical study revealed a distinctive pattern of oligosaccharide .... tissue was used as a positive control and nonimmune.

Mannose-binding lectin polymorphisms and susceptibility to infection in systemic lupus erythematosus

DEFF Research Database (Denmark)

Garred, P; Madsen, H O; Halberg, P

1999-01-01

To determine whether variant alleles in the coding portion of the mannose-binding lectin (MBL) gene are associated with increased susceptibility to systemic lupus erythematosus (SLE) and concomitant infections.......To determine whether variant alleles in the coding portion of the mannose-binding lectin (MBL) gene are associated with increased susceptibility to systemic lupus erythematosus (SLE) and concomitant infections....

Studies on murine plasmocytoma treatment with mistletoe lectin I

International Nuclear Information System (INIS)

Raabe, F.; Storch, H.

1987-01-01

Mistletoe lectin I was tested in vivo and in vitro for its cytotoxic activity against murine plasmacytoma cells P3/X63-Ag8. As a result of this treatment, 30 to 60% of the BALB/c mice developed complete tumor regressions. 83% of the mice treated with mistletoe lectin I were resistant to viable tumor cell challenge after 100 days. The cytotoxic activity in vitro tested by 3 H-thymidine incorporation into P3/X63-Ag8 cells was very high. The rate was markedly reduced at concentrations up to 0.07 ng/ml. (author)

Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin

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Renata Angeli

2009-01-01

Full Text Available A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A and Cratylia mollis (Cramoll 1 and Cramoll 1,4 did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column.

Differential Lectin Binding Patterns Identify Distinct Heart Regions in Giant Danio (Devario aequipinnatus) and Zebrafish (Danio rerio) Hearts

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Manalo, Trina; May, Adam; Quinn, Joshua; Lafontant, Dominique S.; Shifatu, Olubusola; He, Wei; Gonzalez-Rosa, Juan M.; Burns, Geoffrey C.; Burns, Caroline E.; Burns, Alan R.; Lafontant, Pascal J.

2016-01-01

Lectins are carbohydrate-binding proteins commonly used as biochemical and histochemical tools to study glycoconjugate (glycoproteins, glycolipids) expression patterns in cells, tissues, including mammalian hearts. However, lectins have received little attention in zebrafish (Danio rerio) and giant danio (Devario aequipinnatus) heart studies. Here, we sought to determine the binding patterns of six commonly used lectins—wheat germ agglutinin (WGA), Ulex europaeus agglutinin, Bandeiraea simplicifolia lectin (BS lectin), concanavalin A (Con A), Ricinus communis agglutinin I (RCA I), and Lycopersicon esculentum agglutinin (tomato lectin)—in these hearts. Con A showed broad staining in the myocardium. WGA stained cardiac myocyte borders, with binding markedly stronger in the compact heart and bulbus. BS lectin, which stained giant danio coronaries, was used to measure vascular reconstruction during regeneration. However, BS lectin reacted poorly in zebrafish. RCA I stained the compact heart of both fish. Tomato lectin stained the giant danio, and while low reactivity was seen in the zebrafish ventricle, staining was observed in their transitional cardiac myocytes. In addition, we observed unique staining patterns in the developing zebrafish heart. Lectins’ ability to reveal differential glycoconjugate expression in giant danio and zebrafish hearts suggests they can serve as simple but important tools in studies of developing, adult, and regenerating fish hearts. PMID:27680670

Ulex europaeus I lectin as a marker for vascular endothelium in human tissues.

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Holthöfer, H; Virtanen, I; Kariniemi, A L; Hormia, M; Linder, E; Miettinen, A

1982-07-01

Ulex europaeus I agglutinin, a lectin specific for some alpha-L-fucose-containing glycocompounds, was used in fluorescence microscopy to stain cryostat sections of human tissues. The endothelium of vessels of all sizes was stained ubiquitously in all tissues studied as judged by double staining with a known endothelial marker, antibodies against human clotting factor VIII. Cultured human umbilical vein endothelial cells, but not fibroblasts, also bound Ulex lectin. The staining was not affected by the blood group type of the tissue donor. In some tissues Ulex lectin presented additional binding to epithelial structures. Also, this was independent on the blood group or the ability of the tissue donor to secrete soluble blood group substances. Lotus tetragonolobus agglutinin, another lectin specific for some alpha-L-fucose-containing moieties failed to react with endothelial cells. Our results suggest that Ulex europaeus I agglutinin is a good histologic marker for endothelium in human tissues.

Lysis of fresh human solid tumors by autologous lymphocytes activated in vitro with lectins

International Nuclear Information System (INIS)

Mazumder, A.; Grimm, E.A.; Zhang, H.Z.; Rosenberg, S.A.

1982-01-01

Human peripheral blood lymphocytes (PBL), obtained from patients with a variety of cancers, were incubated in vitro with phytohemagglutinin, concanavalin A, and crude or lectin-free T-cell growth factors. The lectin-activated PBL of nine patients were capable of lysing fresh autologous tumor during a 4-hr 51Cr release assay. Multiple metastases from the same patient were equivalently lysed by these activated autologous PBL. No lysis of fresh PBL or lectin-induced lymphoblast cell targets was seen, although tumor, PBL, and lymphoblast cells were shown to be equally lysable using allosensitized cells. The activated cells could be expanded without loss of cytotoxicity in crude or lectin-free T-cell growth factors. The generation of cells lytic to fresh autologous tumor was dependent on the presence of adherent cells, although the lytic cell itself was not adherent. Proliferation was not involved in the induction of lytic cells since equal lysis was induced in irradiated and nonirradiated lymphocytes. Lectin was not required in the lytic assay, and the addition of alpha-methyl-D-mannoside to concanavalin A-activated lymphoid cells did not increase the lysis of fresh tumor cells. Activation by lectin for 3 days appears to be an efficient and convenient method for generating human cells lytic to fresh autologous tumor. These lytic cells may be of value for studies of the cell-mediated lysis of human tumor and possibly for tumor immunotherapy as well

Impact of Mannose-Binding Lectin Deficiency on Radiocontrast-Induced Renal Dysfunction

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Michael Osthoff

2013-01-01

Full Text Available Contrast-induced nephropathy (CIN is the third leading cause of acute renal failure in hospitalized patients. Endothelial dysfunction, renal medullary ischemia, and tubular toxicity are regarded as the most important factors in the pathogenesis of CIN. Mannose-binding lectin (MBL, a pattern recognition protein of the lectin pathway of complement, has been found to aggravate and mediate tissue damage during experimental renal ischemia/reperfusion (I/R injury which was alleviated by inhibition with C1 inhibitor, a potent MBL, and lectin pathway inhibitor. In this paper, we highlight the potential role of MBL in the pathogenesis of human CIN. In experimental I/R models, MBL was previously found to induce tubular cell death independent of the complement system. In addition, after binding to vascular endothelial cells, MBL and its associated serine proteases were able to trigger a proinflammatory reaction and contribute to endothelial dysfunction. In humans, urinary MBL was increased after administration of contrast media and in individuals with CIN. Moreover, individuals with normal/high MBL levels were at increased risk to develop radiocontrast-induced renal dysfunction. Hence, MBL and the lectin pathway seem to be a promising target given that a licensed, powerful, human recombinant inhibitor exits to be added to the scarce armamentarium currently available for prophylaxis of CIN.

Glycophenotype evaluation in cutaneous tumors using lectins labeled with acridinium ester.

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Lima, Luiza Rayanna Amorim; Bezerra, Matheus Filgueira; Almeida, Sinara Mônica Vitalino; Silva, Lúcia Patrícia Bezerra Gomes; Beltrão, Eduardo Isidoro Carneiro; Carvalho Júnior, Luiz Bezerra

2013-01-01

Tumor cells show alterations in their glycosylation patterns when compared to normal cells. Lectins can be used to evaluate these glycocode changes. Chemiluminescence assay is an effective technique for quantitative analysis of proteins, nucleic acids, and carbohydrates due to its high sensitivity, specificity, and rapid testing. To use histochemiluminescence based on lectin conjugated to acridinium ester (AE) for the investigation of glycophenotype changes in cutaneous tumors. Concanavalin A (Con A), Peanut agglutinin (PNA), Ulex europaeus agglutinin-I (UEA-I), and Maackia amurensis agglutinin (MAA) were conjugated to acridinium ester. Biopsies of cutaneous tumors and normal skin were incubated with the lectins-AE, and chemiluminescence was quantified and expressed as Relative Light Units (RLU). Results. Actinic keratosis (AK), keratoacanthoma (KA), squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) showed lower expression of α -D-glucose/mannose and α -L-fucose residues compared to normal tissue. Cutaneous tumors displayed higher expression of Gal- β (1-3)-GalNAc residues than normal tissue. AK and SCC exhibited higher expression of Neu5Ac- α (2,3)Gal residues than normal epidermis. KA and BCC showed equivalent RLU values compared to normal tissue. Lectin histochemiluminescence allowed quantitative assessment of the carbohydrate expression in cutaneous tissues, contributing to eliminate the subjectivity of conventional techniques used in the histopathological diagnosis.

Evaluation of glycophenotype in breast cancer by quantum dot-lectin histochemistry

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Andrade, Camila G; Cabral Filho, Paulo E; Tenório, Denise PL; Santos, Beate S; Beltrão, Eduardo IC; Fontes, Adriana; Carvalho, Luiz B

2013-01-01

Cell surface glycoconjugates play an important role in differentiation/dedifferentiation processes and lectins are employed to evaluate them by several methodologies. Fluorescent probes are considered a valuable tool because of their ability to provide a particular view, and are more detailed and sensitive in terms of cell structure and molecular content. The aim of this study was to evaluate and compare the expression and distribution of glycoconjugates in normal human breast tissue, and benign (fibroadenoma), and malignantly transformed (invasive ductal carcinoma) breast tissues. For this, we used mercaptosuccinic acid-coated Cadmium Telluride (CdTe) quantum dots (QDs) conjugated with concanavalin A (Con A) or Ulex europaeus agglutinin I (UEA I) lectins to detect α-D-glucose/mannose and L-fucose residues, respectively. The QD-lectin conjugates were evaluated by hemagglutination activity tests and carbohydrate inhibition assays, and were found to remain functional, keeping their fluorescent properties and carbohydrate recognition ability. Fluorescence images showed that different regions of breast tissue expressed particular types of carbohydrates. While the stroma was preferentially and intensely stained by QD-Con A, ductal cells were preferentially labeled by QD-UEA I. These results indicate that QD-lectin conjugates can be used as molecular probes and can help to elucidate the glycoconjugate profile in biological processes. PMID:24324334

Effect of Chum Salmon Egg Lectin on Tight Junctions in Caco-2 Cell Monolayers

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Ryo Nemoto

2015-05-01

Full Text Available The effect of a chum salmon egg lectin (CSL3 on tight junction (TJ of Caco-2 cell monolayers was investigated. The lectin opened TJ as indicated by the decrease of the transepithelial electrical resistance (TER value and the increase of the permeation of lucifer yellow, which is transported via the TJ-mediated paracellular pathway. The effects of CSL3 were inhibited by the addition of 10 mM L-rhamnose or D-galactose which were specific sugars for CSL3. The lectin increased the intracellular Ca2+ of Caco-2 cell monolayers, that could be inhibited by the addition of L-rhamnose. The fluorescence immunostaining of β-actin in Caco-2 cell monolayers revealed that the cytoskeleton was changed by the CSL3 treatment, suggesting that CSL3 depolymerized β-actin to cause reversible TJ structural and functional disruption. Although Japanese jack bean lectin and wheat germ lectin showed similar effects in the decrease of the TER values and the increase of the intracellular Ca2+, they could not be inhibited by the same concentrations of simple sugars, such as D-glucose and N-acetyl-D-glucosamine.

[Effect of thyroid hormones on the histotopography of lectin receptors in the rat salivary gland].

Science.gov (United States)

Lutsik, A D; Iashchenko, A M; Detiuk, E S

1987-04-01

Using lectin-peroxidase technique, the influence of hypo- and hyperthyroidism on histotopography of glycoconjugates has been investigated in rat submandibular gland. The following lectins were used: peanut agglutinin (PNA), wheat germ agglutinin (WGA), Laburnum anagyroides lectin (LAL) and concanavalin A (con A). It has been demonstrated that hyperthyroidism is accompanied by the loss of con A, WGA and LAL receptor sites. Hypothyrodism enhanced con A binding to granular duct cells with a parallel reduction in WGA and LAL binding to these or other duct cells. Hypothyroidism as well as hyperthyroidism markedly enhanced PNA binding to duct epitheliocytes with redistribution of these lectin binding sites from the luminal surface of salivary ducts into the cytoplasm of duct cells. Possible interpretations of the observed phenomena are discussed.

Presenting Precision Glycomacromolecules on Gold Nanoparticles for Increased Lectin Binding

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Sophia Boden

2017-12-01

Full Text Available Glyco-functionalized gold nanoparticles have great potential as biosensors and as inhibitors due to their increased binding to carbohydrate-recognizing receptors such as the lectins. Here we apply previously developed solid phase polymer synthesis to obtain a series of precision glycomacromolecules that allows for straightforward variation of their chemical structure as well as functionalization of gold nanoparticles by ligand exchange. A novel building block is introduced allowing for the change of spacer building blocks within the macromolecular scaffold going from an ethylene glycol unit to an aliphatic spacer. Furthermore, the valency and overall length of the glycomacromolecule is varied. All glyco-functionalized gold nanoparticles show high degree of functionalization along with high stability in buffer solution. Therefore, a series of measurements applying UV-Vis spectroscopy, dynamic light scattering (DLS and surface plasmon resonance (SPR were performed studying the aggregation behavior of the glyco-functionalized gold nanoparticles in presence of model lectin Concanavalin A. While the multivalent presentation of glycomacromolecules on gold nanoparticles (AuNPs showed a strong increase in binding compared to the free ligands, we also observed an influence of the chemical structure of the ligand such as its valency or hydrophobicity on the resulting lectin interactions. The straightforward variation of the chemical structure of the precision glycomacromolecule thus gives access to tailor-made glyco-gold nanoparticles (glyco-AuNPs and fine-tuning of their lectin binding properties.

Application of Lectin Array Technology for Biobetter Characterization: Its Correlation with FcγRIII Binding and ADCC

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Markus Roucka

2016-12-01

Full Text Available Lectin microarray technology was applied to compare the glycosylation pattern of the monoclonal antibody MB311 expressed in SP2.0 cells to an antibody-dependent cellular cytotoxic effector function (ADCC-optimized variant (MB314. MB314 was generated by a plant expression system that uses genetically modified moss protoplasts (Physcomitrella patens to generate a de-fucosylated version of MB311. In contrast to MB311, no or very low interactions of MB314 with lectins Aspergillus oryzae l-fucose (AOL, Pisum sativum agglutinin (PSA, Lens culinaris agglutinin (LCA, and Aleuria aurantia lectin (AAL were observed. These lectins are specific for mono-/biantennary N-glycans containing a core fucose residue. Importantly, this fucose indicative lectin-binding pattern correlated with increased MB314 binding to CD16 (FcγRIII; receptor for the constant region of an antibody—whose affinity is mediated through core fucosylation—and stronger ADCC. In summary, these results demonstrate that lectin microarrays are useful orthogonal methods during antibody development and for characterization.

Chitovibrin: a chitin-binding lectin from Vibrio parahemolyticus.

Science.gov (United States)

Gildemeister, O S; Zhu, B C; Laine, R A

1994-12-01

A novel 134 kDa, calcium-independent chitin-binding lectin, 'chitovibrin', is secreted by the marine bacterium Vibrio parahemolyticus, inducible with chitin or chitin-oligomers. Chitovibrin shows no apparent enzymatic activity but exhibits a strong affinity for chitin and chito-oligomers > dp9. The protein has an isoelectric pH of 3.6, shows thermal tolerance, binds chitin with an optimum at pH 6 and is active in 0-4 M NaCl. Chitovibrin appears to be completely different from other reported Vibrio lectins and may function to bind V. parahemolyticus to chitin substrates, or to capture or sequester chito-oligomers. It may be a member of a large group of recently described proteins in Vibrios related to a complex chitinoclastic (chitinivorous) system.

Micro-instillation of fluorescein with an inoculation loop for ocular surface staining in dry eye syndrome.

Science.gov (United States)

Courrier, Emilie; Renault, Didier; Kaspi, Mathilde; Marcon, Agathe; Lambert, Victor; Garcin, Thibaud; Chiambaretta, Frederic; Garhofer, Gerhard; Thuret, Gilles; Gain, Philippe

2018-03-01

To describe and validate the micro-instillation of fluorescein on the ocular surface by a disposable calibrated inoculation loop to improve corneal and conjunctival staining quality. Accuracy and precision of the volume of 0.5% sodium fluorescein collected by a single use 1 μl-calibrated inoculation loop were measured using a precision balance. Twenty patients (40 eyes) suffering from dry eye syndrome were enrolled in a prospective interventional nonrandomized study. Fluorescein was instilled with the loop, and slit-lamp images were taken within 30 seconds using cobalt blue light with and without a yellow barrier filter. For comparison, after a washout period, the same images were retaken after instillation of one drop of fluorescein from a single-dose unit. The main outcome measure was the staining quality assessed by three experts, blind to the instillation method. Patient discomfort (tolerance, by a questionnaire) was also compared. The mean volume collected by the loop was 1.18 ± 0.12 μl, compared with 33.70 ± 6.10 μl using the single-dose unit. The loop avoided excess dye responsible for unpleasant tearing, masking of lesions and rapid diffusion into the stroma. Micro-instillation greatly improved image quality without losing information. The yellow filter further improved image contrast. Tolerance was excellent. The 1 μl-calibrated inoculation loop is a safe, convenient, inexpensive, disposable, sterile, well-tolerated tool for reproducible micro-instillation of commercial fluorescein. By greatly improving staining quality, it will help standardize assessment of dry eye severity. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Characterization and phylogenetic analysis of lectin gene cDNA isolated from sea cucumber ( Apostichopus japonicus) body wall

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Xue, Zhuang; Li, Hui; Liu, Yang; Zhou, Wei; Sun, Jing; Wang, Xiuli

2017-12-01

As a `living fossil' of species origin and `rich treasure' of food and nutrition development, sea cucumber has received a lot of attentions from researchers. The cDNA library construction and EST sequencing of blood had been conducted previously in our lab. The bioinformatic analysis provided a gene fragment which is highly homologous with the genes of lectin family, named AjL ( Apostichopus japonicus lectin). To characterize and determine the phylogeny of AjL genes in early evolution, we isolated a full-length cDNA of lectin gene from the body wall of A. japonicus. The open reading frame of this gene contained 489 bp and encoded a 163 amino acids secretory protein being homologous to lectins of mammals and aquatic organisms. The deduced protein included a lectin-like domain. SDS-PAGE analysis showed that AjL migrated as a specific band (about 36.09 kDa under reducing), and agglutinated against rabbit red blood cells. AjL was similar to chain A of CEL-IV in space structure. We predicted that AjL may play the same role of CEL-IV. Our results suggested that more than one lectin gene functioned in sea cucumber and most of other species, which was fused by uncertain sequences during the evolution and encoded different proteins with diverse functions. Our findings provided the insights into the function and characteristics of lectin genes invertebrates. The results will also be helpful for the identification and structural, functional, and evolutionary analyses of lectin genes.

Association of Low Ficolin-Lectin Pathway Parameters with Cardiac Syndrome X

DEFF Research Database (Denmark)

Horváth, Z; Csuka, Dorottya; Vargova, K

2016-01-01

In patients with typical angina pectoris, inducible myocardial ischaemia and macroscopically normal coronaries (cardiac syndrome X (CSX)), a significantly elevated plasma level of terminal complement complex (TCC), the common end product of complement activation, has been observed without.......003). In conclusion, in patients with typical angina and myocardial ischaemia despite macroscopically normal coronary arteries, low levels of several lectin pathway parameters were observed, indicating complement activation and consumption. Complement activation through the ficolin-lectin pathway might play a role...

Activation of the lectin pathway of complement in experimental human keratitis with Pseudomonas aeruginosa.

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Osthoff, Michael; Brown, Karl D; Kong, David C M; Daniell, Mark; Eisen, Damon P

2014-01-01

Pseudomonas aeruginosa (P. aeruginosa) microbial keratitis (MK) is a sight-threatening disease. Previous animal studies have identified an important contribution of the complement system to the clearance of P. aeruginosa infection of the cornea. Mannose-binding lectin (MBL), a pattern recognition receptor of the lectin pathway of complement, has been implicated in the host defense against P. aeruginosa. However, studies addressing the role of the lectin pathway in P. aeruginosa MK are lacking. Hence, we sought to determine the activity of the lectin pathway in human MK caused by P. aeruginosa. Primary human corneal epithelial cells (HCECs) from cadaveric donors were exposed to two different P. aeruginosa strains. Gene expression of interleukin (IL)-6, IL-8, MBL, and other complement proteins was determined by reverse transcription-polymerase chain reaction (RT-PCR) and MBL synthesis by enzyme-linked immunosorbent assay and intracellular flow cytometry. MBL gene expression was not detected in unchallenged HCECs. Exposure of HCECs to P. aeruginosa resulted in rapid induction of the transcriptional expression of MBL, IL-6, and IL-8. In addition, expression of several complement proteins of the classical and lectin pathways, but not the alternative pathway, were upregulated after 5 h of challenge, including MBL-associated serine protease 1. However, MBL protein secretion was not detectable 18 h after challenge with P. aeruginosa. MK due to P. aeruginosa triggers activation of MBL and the lectin pathway of complement. However, the physiologic relevance of this finding is unclear, as corresponding MBL oligomer production was not observed.

Cytotoxic effect of achatinin(H) (lectin) from Achatina fulica against a human mammary carcinoma cell line (MCF7).

Science.gov (United States)

Dharmu, Indra; Ramamurty, N; Kannan, Ramalingam; Babu, Mary

2007-01-01

The hemolymph-derived achatinin(H) (lectin) from Achatina fulica showed a marked cytotoxic effect on MCF7, a human mammary carcinoma cell line. IC(50) values as measured by the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay for achatinin(H) ranged from 6 to 10 microg/ml in the MCF7 cells. MCF7 cells showed significant morphological changes leading to cell death. The above cell death was observed after 48 h of treatment with 8 microg/ml when compared to untreated cells. Alterations in the tumor marker enzymes, as well as in antioxidant enzymes, were observed after achatinin(H) treatment. The specificity and purity of the achatinin(H) was confirmed by the Western blot assay. Achatinin(H) binding to MCF7 cells was detected by anti-achatinin(H), and visualization of the achatinin(H) binding sites on confluent MCF7 cells was confirmed by flourescein isothiocyanate conjugated secondary antibody. MCF7-treated cells fluoresced, indicating the presence of achatinin(H) binding sites. Fluorescence-activated cell sorting analysis of the cell cycle showed a significant increase in S-phase in MCF7 cells after 48 h of achatinin(H) treatment. The cells were arrested in G(2)/M phase of the cell cycle after 48 h with significant changes in cell viability. Cellular damage was confirmed by agarose gel electrophoresis with the characteristic appearance of a DNA streak in treated MCF7 cells indicating the ongoing apoptosis.

Detection of Cytotoxic Activity of Lectin on Human Colon Adenocarcinoma (Sw480 and Epithelial Cervical Carcinoma (C33-A

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Mirandeli Bautista

2011-03-01

Full Text Available Lectins comprise a heterogeneous class of proteins that recognize the carbohydrate moieties of glycoconjugates with high specificity. Numerous studies have shown that lectins are capable of recognizing specific carbohydrate moieties displayed by malignant cells or tissues. The present work was performed to investigate the effects of tepary bean (Phaseolus acutifolius lectins on proliferation, colony formation, and alteration of DNA synthesis of human malignant cells. Tepary bean lectin showed dose dependent  effects on the inhibition of viability as well as on colony formation in two human malignant cells lines (C33-A, Sw480; By contrast, tepary bean lectin only showed significant effects on DNA synthesis on Sw480 cells. Our results provide evidence of the anti- proliferative and cytotoxic effects of the tepary bean lectins on C33-A and Sw480 cells lines.

Crystallization and preliminary X-ray diffraction analysis of HML, a lectin from the red marine alga Hypnea musciformis

International Nuclear Information System (INIS)

Nagano, Celso S.; Gallego del Sol, Francisca; Cavada, Benildo S.; Nascimento, Kyria Santiago Do; Nunes, Eudismar Vale; Sampaio, Alexandre H.; Calvete, Juan J.

2005-01-01

The crystallization and preliminary X-ray diffraction analysis of a red marine alga lectin isolated from H. musciformis is reported. HML, a lectin from the red marine alga Hypnea musciformis, defines a novel lectin family. Orthorhombic crystals of HML belonging to space group P2 1 2 1 2 1 grew within three weeks at 293 K using the hanging-drop vapour-diffusion method. A complete data set was collected at 2.4 Å resolution. HML is the first marine alga lectin to be crystallized

Plant Lectins Targeting O-Glycans at the Cell Surface as Tools for Cancer Diagnosis, Prognosis and Therapy

Science.gov (United States)

Poiroux, Guillaume; Barre, Annick; van Damme, Els J. M.; Benoist, Hervé; Rougé, Pierre

2017-01-01

Aberrant O-glycans expressed at the surface of cancer cells consist of membrane-tethered glycoproteins (T and Tn antigens) and glycolipids (Lewis a, Lewis x and Forssman antigens). All of these O-glycans have been identified as glyco-markers of interest for the diagnosis and the prognosis of cancer diseases. These epitopes are specifically detected using T/Tn-specific lectins isolated from various plants such as jacalin from Artocarpus integrifola, and fungi such as the Agaricus bisporus lectin. These lectins accommodate T/Tn antigens at the monosaccharide-binding site; residues located in the surrounding extended binding-site of the lectins often participate in the binding of more extended epitopes. Depending on the shape and size of the extended carbohydrate-binding site, their fine sugar-binding specificity towards complex O-glycans readily differs from one lectin to another, resulting in a great diversity in their sugar-recognition capacity. T/Tn-specific lectins have been extensively used for the histochemical detection of cancer cells in biopsies and for the follow up of the cancer progression and evolution. T/Tn-specific lectins also induce a caspase-dependent apoptosis in cancer cells, often associated with a more or less severe inhibition of proliferation. Moreover, they provide another potential source of molecules adapted to the building of photosensitizer-conjugates allowing a specific targeting to cancer cells, for the photodynamic treatment of tumors. PMID:28598369

Purification of a lectin from Eugenia uniflora L. seeds and its potential antibacterial activity.

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Oliveira, M D L; Andrade, C A S; Santos-Magalhães, N S; Coelho, L C B B; Teixeira, J A; Carneiro-da-Cunha, M G; Correia, M T S

2008-03-01

The aim of this work was to analyse the antimicrobial properties of a purified lectin from Eugenia uniflora L. seeds. The E. uniflora lectin (EuniSL) was isolated from the seed extract and purified by ion-exchange chromatography in DEAE-Sephadex with a purification factor of 11.68. The purified lectin showed a single band on denaturing electrophoresis, with a molecular mass of 67 kDa. EuniSL agglutinated rabbit and human erythrocytes with a higher specificity for rabbit erythrocytes. The haemagglutination was not inhibited by the tested carbohydrates but glycoproteins exerted a strong inhibitory action. The lectin proved to be thermo resistant with the highest stability at pH 6.5 and divalent ions did not affect its activity. EuniSL demonstrated a remarkable nonselective antibacterial activity. EuniSL strongly inhibited the growth of Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella sp. with a minimum inhibitory concentration (MIC) of 1.5 microg ml(-1), and moderately inhibited the growth of Bacillus subtilis, Streptococcus sp. and Escherichia coli with a MIC of 16.5 microg ml(-1). EuniSL was found to be effective against bacteria. The strong antibacterial activity of the studied lectin indicates a high potential for clinical microbiology and therapeutic applications.

Feasibility of simultaneous sodium fluorescein and indocyanine green injection in neurosurgical procedures.

Science.gov (United States)

Acerbi, F; Restelli, F; Broggi, M; Schiariti, M; Ferroli, P

2016-07-01

The objective of this study is to assess the feasibility of simultaneous Sodium Fluorescein (SF) and Indocyanine Green (ICG) injection during neurosurgical procedures. Three patients harboring a high-grade glioma (HGG) were retrospectively identified in the surgical database of the Neurosurgical Unit 2 at the Foundation IRCCS Istituto Neurologico C. Besta in Milan, by having received intraoperatively both SF for tumor resection and ICG for vasculature angiographic studies in the same surgical procedure. We identified 2 males and 1 female (age range 25-60). Lesions were located in the left temporo-polar area and hippocampus (1 case), right superior frontal gyrus (1 case), left supplementary motor area (1 case). All the three lesions showed Magnetic Resonance Imaging (MRI) characteristics of HGG and, for this reason, in all patients a fluorescein-guided tumor removal was proposed. In the same surgical procedure ICG videoangiography was considered necessary in order to study arterial and venous vasculature, given by the strict relation of the tumor with an unexpected Posterior Communicating Artery (PComA) aneurysm in one case and with cortical drainage veins complexes in the other two cases. In all cases a microscope equipped with both YELLOW560 and IR800 integrated filters (Pentero 900, Carl Zeiss, Oberkorchen, Germany) was used. Fluorescein was i.v. injected at a dose of 5mg/kg immediately after patient intubation. ICG was i.v. injected in bolus on demand of the operating surgeon at a dose of 12.5mg. No side-effects related to simultaneous injection of SF and ICG were identified. In all three cases, the use of SF allowed to better visualize the tumor areas during surgical removal, thus leading to a radical resection until no macroscopic appearance of residual tumor mass and no fluorescence was visible in the surgical cavity. ICG videoangiography confirmed the patency of branches of internal carotid artery after clipping of an unexpected small PComA aneurysm found

Glycophenotype Evaluation in Cutaneous Tumors Using Lectins Labeled with Acridinium Ester

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Luiza Rayanna Amorim Lima

2013-01-01

Full Text Available Background. Tumor cells show alterations in their glycosylation patterns when compared to normal cells. Lectins can be used to evaluate these glycocode changes. Chemiluminescence assay is an effective technique for quantitative analysis of proteins, nucleic acids, and carbohydrates due to its high sensitivity, specificity, and rapid testing. Objective. To use histochemiluminescence based on lectin conjugated to acridinium ester (AE for the investigation of glycophenotype changes in cutaneous tumors. Methods. Concanavalin A (Con A, Peanut agglutinin (PNA, Ulex europaeus agglutinin-I (UEA-I, and Maackia amurensis agglutinin (MAA were conjugated to acridinium ester. Biopsies of cutaneous tumors and normal skin were incubated with the lectins-AE, and chemiluminescence was quantified and expressed as Relative Light Units (RLU. Results. Actinic keratosis (AK, keratoacanthoma (KA, squamous cell carcinoma (SCC, and basal cell carcinoma (BCC showed lower expression of α-D-glucose/mannose and α-L-fucose residues compared to normal tissue. Cutaneous tumors displayed higher expression of Gal-β(1-3-GalNAc residues than normal tissue. AK and SCC exhibited higher expression of Neu5Ac-α(2,3Gal residues than normal epidermis. KA and BCC showed equivalent RLU values compared to normal tissue. Conclusions. Lectin histochemiluminescence allowed quantitative assessment of the carbohydrate expression in cutaneous tissues, contributing to eliminate the subjectivity of conventional techniques used in the histopathological diagnosis.

Fungal lectin MpL enables entry of protein drugs into cancer cells and their subcellular targeting

OpenAIRE

?urga, Simon; Nanut, Milica Peri?i?; Kos, Janko; Saboti?, Jerica

2017-01-01

Lectins have been recognized as promising carrier molecules for targeted drug delivery. They specifically bind carbohydrate moieties on cell membranes and trigger cell internalization. Fungal lectin MpL (Macrolepiota procera lectin) does not provoke cancer cell cytotoxicity but is able to bind aminopeptidase N (CD13) and integrin ?3?1, two glycoproteins that are overexpressed on the membrane of tumor cells. Upon binding, MpL is endocytosed in a clathrin-dependent manner and accumulates initia...

Purification, characterization and biological effect of lectin from the marine sponge Stylissa flexibilis (Lévi, 1961).

Science.gov (United States)

Hung, Le Dinh; Ly, Bui Minh; Hao, Vo Thi; Trung, Dinh Thanh; Trang, Vo Thi Dieu; Trinh, Phan Thi Hoai; Ngoc, Ngo Thi Duy; Quang, Thai Minh

2018-02-01

SFL, a lectin from the marine sponge Stylissa flexibilis was purified by cold ethanol precipitation followed by ion exchange chromatography on DEAE Sepharose column and Sephacryl S-200 gel filtration. SFL is a dimeric glycoprotein of 32kDa subunits linked by a disulfide bridge with a molecular mass of 64kDa by SDS-PAGE and 65kDa by Sephacryl S-200 gel filtration. SFL preferentially agglutinated enzyme treated human A erythrocytes. The activity of lectin was strongly inhibited by monosaccharide d-galactose and glycoproteins asialo-porcine stomach mucin and asialo-fetuin. The lectin was Ca 2+ dependent, stable over a range of pH from 5 to 8, and up to 60°C for 30min. The N-terminal amino acid sequence of SFL was also determined and a blast search on amino acid sequences revealed that the protein showed similarity only with lectins from the marine sponge Spheciospongia vesparia. SFL caused agglutination of Vibrio alginolyticus and V. parahaemolyticus in a dose dependent manner and inhibited the growth rates of the virulent bacterial strains. Growth inhibition of V. alginolyticus and V. parahaemolyticus with SFL was not observed in the presence of d-galactose or asialo-porcine stomach mucin, suggesting that the lectin caused the agglutination through binding to the target receptor(s) on the surface of Vibrios. Thus, the marine sponge S. flexibilis could promise to be a good source of a lectin(s) that may be useful as a carbohydrate probe and an antibacterial reagent. Copyright © 2017 Elsevier Inc. All rights reserved.

Clinical manifestations of mannan-binding lectin deficiency

DEFF Research Database (Denmark)

Thiel, S; Frederiksen, P D; Jensenius, Jens Christian

2006-01-01

Mannan-binding lectin (MBL) is a plasma protein of the innate immune system with the ability to initiate antimicrobial and inflammatory actions. MBL deficiency is common. More than 10% of the general population may, depending on definition, be classified as MBL deficient, underlining the redundan...

Transfer of bacteriophage MS2 and fluorescein from N95 filtering facepiece respirators to hands: Measuring fomite potential

Science.gov (United States)

Brady, Tyler M.; Strauch, Amanda L.; Almaguer, Claudia M.; Niezgoda, George; Shafer, Ronald E.; Yorio, Patrick L.; Fisher, Edward M.

2017-01-01

Contact transmission of pathogens from personal protective equipment is a concern within the healthcare industry. During public health emergency outbreaks, resources become constrained and the reuse of personal protective equipment, such as N95 filtering facepiece respirators, may be needed. This study was designed to characterize the transfer of bacteriophage MS2 and fluorescein between filtering facepiece respirators and the wearer’s hands during three simulated use scenarios. Filtering facepiece respirators were contaminated with MS2 and fluorescein in droplets or droplet nuclei. Thirteen test subjects performed filtering facepiece respirator use scenarios including improper doffing, proper doffing and reuse, and improper doffing and reuse. Fluorescein and MS2 contamination transfer were quantified. The average MS2 transfer from filtering facepiece respirators to the subjects’ hands ranged from 7.6–15.4% and 2.2–2.7% for droplet and droplet nuclei derived contamination, respectively. Handling filtering facepiece respirators contaminated with droplets resulted in higher levels of MS2 transfer compared to droplet nuclei for all use scenarios (p = 0.007). MS2 transfer from droplet contaminated filtering facepiece respirators during improper doffing and reuse was greater than transfer during improper doffing (p = 0.008) and proper doffing and reuse (p = 0.042). Droplet contamination resulted in higher levels of fluorescein transfer compared to droplet nuclei contaminated filtering facepiece respirators for all use scenarios (p = 0.009). Fluorescein transfer was greater for improper doffing and reuse (p = 0.007) from droplet contaminated masks compared to droplet nuclei contaminated filtering facepiece respirators and for improper doffing and reuse when compared improper doffing (p = 0.017) and proper doffing and reuse (p = 0.018) for droplet contaminated filtering facepiece respirators. For droplet nuclei contaminated filtering facepiece respirators, the

Effects of plant lectins on in vitro fibroblast proliferation

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Ana Maria Sell

2003-06-01

Full Text Available Lectins are carbohydrate-binding proteins that have been isolated from various sources and presented a wide spectrum of biological activities. The effects of four lectins, namely, Phaseolus vulgaris phytohemagglutinin, PHA, wheat germ agglutinin, WGA, Artocarpus integrifolia seed lectins, jacalin and artocarpin, on in vitro fibroblasts proliferation were investigated. The lectins did not influence the initial cell adhesion to the plate. PHA and WGA at 10-20 µg/mL concentrations significantly decreased fibroblasts proliferation. At these concentrations, they caused morphological alterations on cells and over 80 µg/mL, promoted cell death. Neither jacalin nor artocarpin significantly affected cell proliferation.O objetivo deste trabalho foi avaliar a influência das lectinas PHA, WGA, jacalina e artocarpina sobre a proliferação de fibroblastos in vitro. Para tanto, fibroblastos gengivais de voluntários saudáveis foram cultivados, por cinco dias, em DMEM suplementado com soro bovino fetal (10% v/v e na presença das lectinas nas concentrações finais de 0.1 a 300 µg/mL. A adesão, o crescimento e a morfologia celular foram acompanhados por microscopia de inversão e contraste de fase. O índice de proliferação foi avaliado pelo método calorimétrico usando MTT. As lectinas não alteraram a adesão inicial dos fibroblastos à placa de poliestireno. PHA e WGA, nas concentrações de 10 a 20 µg/mL, diminuíram significativamente a proliferação celular. Nestas concentrações a morfologia celular é alterada e acima de 80 µg/mL, houve100% de morte celular. As lectinas jacalina e artocarpina não influenciaram a proliferação celular.

Bioavailability of Isothiocyanates From Broccoli Sprouts in Protein, Lipid, and Fiber Gels

OpenAIRE

Oliviero, Teresa; Lamers, Simone; Capuano, Edoardo; Dekker, Matthijs; Verkerk, Ruud

2018-01-01

Scope: Optimization of bioavailability of dietary bioactive health-beneficial compounds is as important as increasing their concentration in foods. The aim of this study is to explore the change in bioavailability of isothiocyanates (ITCs) in broccoli sprouts incorporated in protein, fiber, and lipid gels. Methods and results: Five participants took part in a cross-over study and collected timed urine samples up to 24 h after consumption of proteins, dietary fibers, and lipid gels containing ...

Interaction of hamster submaxillary sialyl-Tn and Tn glycoproteins with Gal, GalNAc and GlcNAc specific lectins.

Science.gov (United States)

Wu, A M; Shen, F; Herp, A; Wu, J H

1994-04-01

Hamster submaxillary glycoprotein (HSM), one of the simplest glycoproteins among mammalian salivary mucins, is composed of approximately equivalent amounts of protein, hexosamine and sialic acid. The Thr and Ser residues in the protein core account for more than half of all of the amino acid residues, while Lys, Glu, Pro and Ala are the major components of the remaining portion of amino acids. The carbohydrate side chains of this mucous glycoprotein have mainly the NeuAc-GalNAc-(sialyl-Tn) sequence (HSM), and those of the desialylated product (HSM-Tn) are almost exclusively unsubstituted GalNAc residues (Tn determinants). The binding properties of sialyl-Tn (HSM) and asialo-HSM (HSM-Tn) glycoproteins were tested by precipitin assay with Gal, GalNAc and GlcNAc specific lectins. The HSM-Tn completely precipitated Vicia villosa (VVL both B4 and mixture of A and B), Maclura pomifera (MPL), and Artocarpus integrifolia (Jacalin) lectins; less than 2 micrograms of HSM-Tn were required for precipitating 50% of 5.0-6.3 micrograms lectin nitrogen added. HSM-Tn also reacted well with Helix pomatia lectin (HPL), Wistaria floribunda lectin (WFL) and Abrus precatorius agglutinin (APA) and precipitated in each case over 81% of the lectin nitrogen added. The reactivity of HSM-Tn with other lectins (Ricinus communis, RCA1; Dolichol biflorus, DBL; Viscum album, ML-I; Arachis hypogaea, PNA, and Triticum vulgaris, WGA) was weak or negligible. The activity of sialyl-Tn (HSM) was more restricted; HSM reacted well with Jacalin, moderately with MPL and VVL-B4, but was inactive or only weakly with the other lectins used. These findings indicate that HSM and its desialylated product (HSM-Tn) are highly useful reagents for the differentiation of Tn and T/Gal specific lectins and for anti-T, Tn and Af monoclonal antibodies.

Mannose-binding lectin variant alleles and the risk of arterial thrombosis in systemic lupus erythematosus

DEFF Research Database (Denmark)

Øhlenschlaeger, Tommy; Garred, Peter; Madsen, Hans O

2004-01-01

Cardiovascular disease is an important complication in patients with systemic lupus erythematosus (SLE). Variant alleles of the mannose-binding lectin gene are associated with SLE as well as with severe atherosclerosis. We determined whether mannose-binding lectin variant alleles were associated...

Characterization of the okra mucilage by interaction with Gal, GalNAc and GlcNAc specific lectins.

Science.gov (United States)

Wu, A M; Jiang, Y J; Hwang, P Y; Shen, F S

1995-02-23

A bio-active polysaccharide, which was the major component of the extract of the common okra, Hibiscus esculentus, was isolated from the extract by precipitation with ethanol between 28.5 to 45%. According to a previous report (Whistler, R.L. and Conrad, H.E. (1954) J. Am. Chem. Soc. 76, 1673-1674), this polysaccharide contains the Gal alpha 1-->4Gal sequence, which is the ligand for the uropathogenic Escherichia coli and toxic lectins. Analysis of the binding property of the okra polysaccharide by precipitin assay with Gal, GalNAc and GlcNAc specific lectins showed that this okra mucilage reacted best with Mistletoe toxic lectin-I (ML-I) and precipitated over 80% of the ML-I nitrogen (5.1 micrograms N) added. It also precipitated well with Abrus precatorius (APA), Momordica charantia (MCA) and Ricinus communis (RCA1) agglutinins, but poorly with other lectins. The results obtained suggest that this polysaccharide is a valuable reagent to differentiate Gal specific lectins from the GalNAc and/or GlcNAc specific series.

Fluorescence quenching of fluorescein by Merocyanine 540 in liposomes

International Nuclear Information System (INIS)

Toprak, Mahmut; Meryem Aydin, Burcu; Arik, Mustafa; Onganer, Yavuz

2011-01-01

The fluorescence quenching of fluorescein (FL) by merociyanine 540 (MC540) was examined in L-egg lecithin phosphatidycholine (PC) liposomes using spectroscopic methods. The type of quenching mechanism (dynamic or static) was evaluated using the Stern-Volmer plots. Findings were also supported by the temperature studies and florescence decay measurements. The Stern-Volmer equation was utilized to calculate bimolecular quenching constants (K q ). Furthermore, the bimolecular quenching constant of the quencher in the liposomes (K SV ), partition coefficient (K p ), binding constant (K), and corresponding thermodynamic parameters ΔH, ΔS, and ΔG were calculated. The quenching property was also used in determining quantitatively (K p ) the partition coefficient of Merociyanini 540 in PC liposome.The obtained data indicated that static quenching occurred in the system and the K SV values decreased with increasing lipid concentration. In addition, thermodynamic analysis suggested that van der Waals interactions and hydrogen bonding were the main acting forces between fluorescein and merociyanine 540 molecules in the medium. - Highlights: → Fluorescence quenching of FL by MC540 in liposome system was analyzed. → Fluorescence quenching mechanism of FL by MC540 was consistent with the static model. → Binding FL to MC540 was spontaneous and carried out by hydrogen bond and van der Waals forces.

A novel C-type lectin identified by EST analysis in tissue migratory larvae of Ascaris suum.

Science.gov (United States)

Yoshida, Ayako; Nagayasu, Eiji; Horii, Yoichiro; Maruyama, Haruhiko

2012-04-01

C-type lectins (CTLs) are a group of proteins which bind to carbohydrate epitopes in the presence of Ca(2+), which have been described in a wide range of species. In this study, a cDNA sequence coding a putative CTL has been identified from the cDNA library constructed from the pig round worm Ascaris suum lung L3 (LL3) larvae, which was designated as A. suum C-type lectin-1 (As-CTL-1). The 510 nucleotide open reading frame of As-CTL-1 cDNA encoded the predicted 169 amino acid protein including a putative signal peptide of 23 residues and C-type lectin/C-type lectin-like domain (CLECT) at residue 26 to 167. As-CTL-1 was most similar to Toxocara canis C-type lectin-1 and 4 (Tc-CTL-1 and 4), and highly homologous to namatode CTLs and mammalian CTLs as well, such as human C-type lectin domain family 4 member G (CLECG4). In addition, As-CTL-1 was strongly expressed in tissue migrating LL3 and the L4 larvae, which were developmental larvae stages within the mammalian host. These results suggest that A. suum larvae might utilize As-CTL-1 to avoid pathogen recognition mechanisms in mammalian hosts due to it is similarity to host immune cell receptors.

Cell surface of sea urchin micromeres and primary mesenchyme

International Nuclear Information System (INIS)

DeSimone, D.W.

1985-01-01

The cell surface and extracellular matrix (ECM) of the sea urchin embryo were studied during the early morphogenetic events involved in the differentiation of the micromere cell lineage. Sixteen-cell and early cleavage stage blastomeres were isolated and the protein composition of their cell surfaces examined by 125 I-labelling followed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Micromere-specific cell surface proteins are reported for Arbacia punctulata, Strongylocentrotus droebachiensis, and Strongylocentrotus purpuratus. Cell surface glycoproteins were characterized on the basis of lectin binding specificity with a novel lectin affinity transfer technique. Using this procedure, cell-type specific surface proteins, which are also lectin-binding specific, can be detected. In addition, fluorescein conjugated lectins were microinjected into the blastocoels of living S. drobachiensis and Lytechinus pictus embryos and the patterns of lectin bindings observed by fluorescence microscopy. The evidence presented in this thesis suggests that the differentiation of the primary mesenchyme cells is correlated with changes in the molecular composition of the cell-surface and the ECM

Antinociceptive and Anti-inflammatory Effects of a Lectin-Like Substance from Clitoria fairchildiana R. Howard Seeds

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Tatiane Santi-Gadelha

2012-03-01

Full Text Available Lectins are proteins that have the ability to bind specifically and reversibly to carbohydrates and glycoconjugates, without altering the structure of the glycosyl ligand. They are found in organisms such as viruses, plants and humans, and they have been shown to possess important biological activities. The objective of this study was to purify and characterize lectins in the seeds of Clitoria fairchildiana, as well as to verify their biological activities. The results indicated the presence of a lectin (CFAL in the glutelin acid protein fraction, which agglutinated native rabbit erythrocytes. CFAL was purified by column chromatography ion-exchange, DEAE-Sephacel, which was obtained from a peak of protein retained in the matrix by applying 0.5 M NaCl using the step-wise method. Electrophoretic analysis of this lectin in SDS-PAGE indicated a two band pattern protein molecular mass of approximately 100 and 116 kDa. CFAL proved to be unspecific to all carbohydrates/glycoconjugates in common use for the sugar inhibition test. This lectin showed no significant cytotoxicity to human red blood cells. It was observed that CFAL has anti-inflammatory activity in the paw edema induced by carrageenan model, in which a 64% diminution in edema was observed. Antinociceptive effects were observed for CFAL in the abdominal writhing test (induced by acetic acid, in which increasing doses of the lectin caused reduction in the number of contortions by up to 72%. It was concluded that the purified and characterized lectin from the seeds of Clitoria fairchildiana has anti-inflammatory and antinociceptive activity, and is not cytotoxic to human erythrocytes.

Taste detection of the non-volatile isothiocyanate moringin results in deterrence to glucosinolate-adapted insect larvae

NARCIS (Netherlands)

Müller, Caroline; Loon, Van Joop; Ruschioni, Sara; Nicola, De Gina Rosalinda; Olsen, Carl Erik; Iori, Renato; Agerbirk, Niels

2015-01-01

Isothiocyanates (ITCs), released from Brassicales plants after hydrolysis of glucosinolates, are known for their negative effects on herbivores but mechanisms have been elusive. The ITCs are initially present in dissolved form at the site of herbivore feeding, but volatile ITCs may subsequently

Red kidney bean (Phaseolus vulgaris lectin stimulation increases the number of enterochromaffin cells in the small intestine of suckling piglets

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Zacharko-Siembida Anna

2014-06-01

Full Text Available The quantities and distribution patterns of serotonin-immunoreactive (serotonin-IR enterochromaffin cells (EC were studied immunohistochemically in the small intestine of suckling piglets stimulated with red kidney bean lectin, and in nonstimulated, control animals. The co-expression patterns of serotonin with somatostatin (SOM or corticotropin releasing-factor (CRF were also studied. After the lectin treatment, the increased numbers of EC were noted in the duodenum of experimental animals. Lectin stimulation did not change the proportions of EC in the jejunum and ileum. In the duodenal epithelium of the lectin-stimulated piglets, the vast majority of serotonin-IR EC were distributed at the basis of crypts. After the lectin administration, the proportions of serotonin-IR/SOM-IR EC were statistically similar in all sections of the small intestine. No upregulation of CRF was found in duodenal, jejunal, and ileal EC of lectin-treated animals. The findings demonstrated that red kidney bean lectin increased the serotonin reservoir in the duodenum, and thus may be an effective stimulant of the gut maturation in suckling mammals.

Purification of a novel chitin-binding lectin with antimicrobial and antibiofilm activities from a bangladeshi cultivar of potato (Solanum tuberosum).

Science.gov (United States)

Hasan, Imtiaj; Ozeki, Yasuhiro; Kabir, Syed Rashel

2014-04-01

A new chitin-binding lectin was purified from a Bangladeshi cultivar 'Deshi' of potato (Solanum tuberosum L.) through anion-exchange and affinity chromatographies using a chitin column. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed the molecular mass of the lectin as 20,000 Daltons. This molecular mass was almost half of the molecular masses of chitin-binding lectins derived from other potatoes. The lectin showed both bactericidal and growth-inhibiting activities against Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli, Salmonella enteritidis and Shigella boydii) pathogenic bacteria. It also showed antifungal activity against Rhizopus spp., Penicillium spp. and Aspergillus niger. Biofilm produced by the bacterium Pseudomonas aeruginosa was dose-dependently reduced by 5-20% in 24 h after administration of the lectin, which was attributed to the glycan-binding property of the lectin having affinity to GlcNAc polymers. It was the first observation that any potato lectin prevented biofilm formation by P. aeruginosa and, therefore, could have possible applications in clinical microbiology and biomedical science.

Expression of binding properties of Gal/GalNAc reactive lectins by mammalian glycotopes (an updated report).

Science.gov (United States)

Wu, A M

2001-01-01

Expression of the binding properties of Gal/GalNAc specific lectins, based on the affinity of decreasing order of mammalian glycotopes (determinants) rather than monosaccharide inhibition pattern, is probably one of the best ways to express carbohydrate specifity and should facilitate the selection of lectins as structural probes for studying mammalian glycobiology. Eleven mammalian structural units have been selected to express the binding domain of applied lectins. They are: 1. F, GalNAcalpha1 --> 3GalNAc; 2. A, GalNAcalpha1 --> 3Gal; 3. T, Galbeta1 --> 3GalNAc; 4. I, Galbeta 1 --> 3GlcNAc; 5. II, Galbeta1 --> 4GlcNAc; 6. B, Galalpha1 --> 3Gal; 7. E, Galalpha1--> 4Gal; 8. L, Galbeta1 --> 4Glc; 9. P, GalNAcbeta1 --> 3Gal; 10. S, GalNAcbeta1 --> 4Gal and 11. Tn, GalNAcalpha1 --> 4Ser (Thr) of the peptide chain. Thus, the carbohydrate specificity of Gal/GalNAc reactive lectins can be divided into classes according to their highest affinity for the above disaccharides and/or Tn residue. Examples of the binding properties of these lectins can be demonstrated by Ricimus communis agglutinin (RCA1), grouped as II specific lectin and its binding property is II > I > B > T; Ahrus precatorius agglutinin (APA), classified as T and its carbohydrate specificity is T > I/II > E > B > Tn; Artocarpus integrifolia (jacalin, AIL), as T/Tn specific and its binding reactivity is T > Tn > I (II) and Geodia cydonium (GCL), as F/A specific, and with affinity for F > Ah [GalNAcalpha1-->43(L(Fuc)alpha1-->2)Gal] > I > L. Due to the multiple reactivity of lectins toward mammalian glycotopes, the possible existence of different combining sites or subsites in the same molecule has to be examined, and the differential binding properties of these combining sites (if any) have to be characterized. To establish the relationship among the amino acid sequences of the combining sites of plant lectins and mammalian glycotopes should be an important direction to be addressed in lectinology.

Mannan-binding lectin in astma and allergy

DEFF Research Database (Denmark)

Kaur, S.; Thiel, Steffen; Sarma, P.U.

2006-01-01

Mannan-binding lectin (MBL) is a vital and versatile component of innate immunity. It is present in serum and may bind to a plethora of microbial pathogens and mediate opsonization of these by complement-dependent and/or independent mechanisms. Low-MBL levels in serum, attributed to certain genet...

Transmission-Blocking Antibodies against Mosquito C-Type Lectins for Dengue Prevention

Science.gov (United States)

Liu, Yang; Zhang, Fuchun; Liu, Jianying; Xiao, Xiaoping; Zhang, Siyin; Qin, Chengfeng; Xiang, Ye; Wang, Penghua; Cheng, Gong

2014-01-01

C-type lectins are a family of proteins with carbohydrate-binding activity. Several C-type lectins in mammals or arthropods are employed as receptors or attachment factors to facilitate flavivirus invasion. We previously identified a C-type lectin in Aedes aegypti, designated as mosquito galactose specific C-type lectin-1 (mosGCTL-1), facilitating the attachment of West Nile virus (WNV) on the cell membrane. Here, we first identified that 9 A. aegypti mosGCTL genes were key susceptibility factors facilitating DENV-2 infection, of which mosGCTL-3 exhibited the most significant effect. We found that mosGCTL-3 was induced in mosquito tissues with DENV-2 infection, and that the protein interacted with DENV-2 surface envelop (E) protein and virions in vitro and in vivo. In addition, the other identified mosGCTLs interacted with the DENV-2 E protein, indicating that DENV may employ multiple mosGCTLs as ligands to promote the infection of vectors. The vectorial susceptibility factors that facilitate pathogen invasion may potentially be explored as a target to disrupt the acquisition of microbes from the vertebrate host. Indeed, membrane blood feeding of antisera against mosGCTLs dramatically reduced mosquito infective ratio. Hence, the immunization against mosGCTLs is a feasible approach for preventing dengue infection. Our study provides a future avenue for developing a transmission-blocking vaccine that interrupts the life cycle of dengue virus and reduces disease burden. PMID:24550728

Crystallization and X-ray analysis of the salmon-egg lectin SEL24K

Energy Technology Data Exchange (ETDEWEB)

Murata, Kenji [Department of Animal Science, University of California, Davis 95616 (United States); Fisher, Andrew J. [Department of Chemistry, University of California, Davis 95616 (United States); Hedrick, Jerry L., E-mail: jlhedrick@ucdavis.edu [Department of Animal Science, University of California, Davis 95616 (United States)

2007-05-01

The 24 kDa egg lectin of Chinook salmon (Oncorhynchus tshawytscha) was purified by affinity chromatography from salmon eggs and crystallized by the hanging-drop vapor-diffusion method using 15/4 EO/OH (pentaerythritol ethoxylate) as a precipitant. The 24 kDa egg lectin of Chinook salmon (Oncorhynchus tshawytscha) is released from the egg during the cortical reaction. The lectin functions in blocking polyspermy during the fertilization process. The egg lectin was purified by affinity chromatography from salmon eggs and crystallized by the hanging-drop vapor-diffusion method using 15/4 EO/OH (pentaerythritol ethoxylate) as a precipitant. The crystal diffracted synchrotron-radiation X-rays to 1.63 Å resolution. The crystal belongs to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 93.0, b = 73.6, c = 113.6 Å, α = 90, β = 92.82, γ = 90°. The crystal is likely to contain eight molecules in the asymmetric unit (V{sub M} = 2.3 Å{sup 3} Da{sup −1}), corresponding to a solvent content of 45.5%. A self-rotation function suggests an arrangement with 222 point symmetry within the asymmetric unit.

Unusual sugar specificity of banana lectin from Musa paradisiaca and its probable evolutionary origin. Crystallographic and modelling studies.

Science.gov (United States)

Singh, D D; Saikrishnan, K; Kumar, Prashant; Surolia, A; Sekar, K; Vijayan, M

2005-10-01

The crystal structure of a complex of methyl-alpha-D-mannoside with banana lectin from Musa paradisiaca reveals two primary binding sites in the lectin, unlike in other lectins with beta-prism I fold which essentially consists of three Greek key motifs. It has been suggested that the fold evolved through successive gene duplication and fusion of an ancestral Greek key motif. In other lectins, all from dicots, the primary binding site exists on one of the three motifs in the three-fold symmetric molecule. Banana is a monocot, and the three motifs have not diverged enough to obliterate sequence similarity among them. Two Greek key motifs in it carry one primary binding site each. A common secondary binding site exists on the third Greek key. Modelling shows that both the primary sites can support 1-2, 1-3, and 1-6 linked mannosides with the second residue interacting in each case primarily with the secondary binding site. Modelling also readily leads to a bound branched mannopentose with the nonreducing ends of the two branches anchored at the two primary binding sites, providing a structural explanation for the lectin's specificity for branched alpha-mannans. A comparison of the dimeric banana lectin with other beta-prism I fold lectins, provides interesting insights into the variability in their quaternary structure.

Griffithsin: An Antiviral Lectin with Outstanding Therapeutic Potential

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Sabrina Lusvarghi

2016-10-01

Full Text Available Griffithsin (GRFT, an algae-derived lectin, is one of the most potent viral entry inhibitors discovered to date. It is currently being developed as a microbicide with broad-spectrum activity against several enveloped viruses. GRFT can inhibit human immunodeficiency virus (HIV infection at picomolar concentrations, surpassing the ability of most anti-HIV agents. The potential to inhibit other viruses as well as parasites has also been demonstrated. Griffithsin’s antiviral activity stems from its ability to bind terminal mannoses present in high-mannose oligosaccharides and crosslink these glycans on the surface of the viral envelope glycoproteins. Here, we review structural and biochemical studies that established mode of action and facilitated construction of GRFT analogs, mechanisms that may lead to resistance, and in vitro and pre-clinical results that support the therapeutic potential of this lectin.

Expression of C-type lectin receptor mRNA in chronic otitis media with cholesteatoma.

Science.gov (United States)

Kim, Sang Hoon; Han, Seung-Ho; Byun, Jae Yong; Park, Moon Suh; Kim, Young Il; Yeo, Seung Geun

2017-06-01

The levels of expression of various C-type lectin receptors (CLRs) messenger ribo nucleic acids (mRNAs) were significantly higher in cholesteatomas than in normal skin, suggesting that these CLRs may be involved in the pathogenesis of cholesteatoma. Altered expression of pattern recognition receptors may be associated with immune responses in patients with cholesteatoma. This study assessed the levels of expression of CLR mRNAs in normal skin and in cholesteatoma. Cholesteatoma specimens were obtained from 38 patients with acquired cholesteatoma. The levels of expression of various CLR mRNAs were assessed quantitatively using real-time RT-PCR (Reverse transcription polymerase chain reaction) and correlated with age, sex, the presence of bacteria, hearing level, frequency of surgery, and degree of ossicle destruction. The levels of CD206 (cluster of differentiation 206), DEC-205 (Dendritic and epithelial cell-205), MGL (monoacylglycerol lipase), CLEC5A (C-type lectin domain family 5 member A), Dectin-2 (dendrite cell-associated C-type lectin-2), BDCA2 (Blood dendritic cell antigen 2), Mincle, DCIR (dendritic cell immunoreceptor), Dectin-1, MICL (Myeloid inhibitory C type-like lectin), and CLEC12B (C-type lectin domain family 12, member B) mRNAs were significantly higher in cholesteatoma than in control skin samples (p C-type lectin domain family 5 member) and Dectin-1 mRNAs were significantly higher in cholesteatomas with ≥2 than ≤1 destroyed ossicles (p < 0.05), and the levels of MGL, Mincle, Dectin-1, and CLEC12B mRNAs were significantly higher in recurrent than initial cholesteatoma specimens (p < 0.05). The level of CLEC5A mRNAs was significantly higher in patients with severe than mild-to-moderate hearing loss (p < 0.05).

Inactivation of Salmonella in tomato stem scars by organic acid wash and chitosan-allyl isothiocyanate coating

Science.gov (United States)

The objective of this study was to evaluate inactivation of inoculated Salmonella enterica on tomato stem scars exploiting integrated treatment of organic acid wash (AW) followed by chitosan-allyl isothiocyanate (CT-AIT) coating. The treatment effect on microbial loads and fruit quality during 21 d...

Plant Lectins as Medical Tools against Digestive System Cancers.

Science.gov (United States)

Estrada-Martínez, Laura Elena; Moreno-Celis, Ulisses; Cervantes-Jiménez, Ricardo; Ferriz-Martínez, Roberto Augusto; Blanco-Labra, Alejandro; García-Gasca, Teresa

2017-07-03

Digestive system cancers-those of the esophagus, stomach, small intestine, colon-rectum, liver, and pancreas-are highly related to genetics and lifestyle. Most are considered highly mortal due to the frequency of late diagnosis, usually in advanced stages, caused by the absence of symptoms or masked by other pathologies. Different tools are being investigated in the search of a more precise diagnosis and treatment. Plant lectins have been studied because of their ability to recognize and bind to carbohydrates, exerting a variety of biological activities on animal cells, including anticancer activities. The present report integrates existing information on the activity of plant lectins on various types of digestive system cancers, and surveys the current state of research into their properties for diagnosis and selective treatment.

A unique epidermal mucus lectin identified from catfish (Silurus asotus): first evidence of intelectin in fish skin slime.

Science.gov (United States)

Tsutsui, Shigeyuki; Komatsu, Yukie; Sugiura, Takaya; Araki, Kyosuke; Nakamura, Osamu

2011-11-01

The present study reports a new type of skin mucus lectin found in catfish Silurus asotus. The lectin exhibited calcium-dependent mannose-binding activity. When mannose eluate from chromatography with mannose-conjugated agarose was analysed by SDS-PAGE, the lectin appeared as a single 35-kDa band. Gel filtration showed that the lectin forms monomers and dimers. A 1216-bp cDNA sequence obtained by RACE-PCR from the skin encoded a 308 amino acid secretory protein with homology to mammalian and fish intelectins. RT-PCR demonstrated that the lectin gene was expressed in the gill, kidney and skin. Subsequent sequencing revealed the presence of an isoform in the gills. Antiserum detected the intelectin protein in club cells in the skin and gill, renal tubules and blood plasma. Although intelectin gene expression was not induced by in vivo bacterial stimulation, the intelectin showed agglutination activity against the pathogenic bacterium Aeromonas salmonicida, suggesting that the lectin plays an important role in self-defence against bacteria in the skin surface of the catfish. These findings represent one of the few examples of characterization and functional analysis of a fish intelectin protein.

Serine protease immunohistochemistry and lectin histochemistry in the small intestine of weaned and unweaned pigs

DEFF Research Database (Denmark)

Brown, P J; Poulsen, Steen Seier; Wells, M

1991-01-01

The distribution of goblet cells containing serine protease and of those binding the lectin Ulex europaeus agglutinin-1 (UEA-1) in the pig small intestine is altered during the period after weaning. Goblet cells exhibiting binding of other lectins were not altered. These alterations and other...

Recombinant production of plant lectins in microbial systems for biomedical application – the frutalin case study

Directory of Open Access Journals (Sweden)

Carla eOliveira

2014-08-01

Full Text Available Frutalin is a homotetrameric partly-glycosylated alpha-D-galactose-binding lectin of biomedical interest from Artocarpus incisa (breadfruit seeds, belonging to the jacalin-related lectins family. As other plant lectins, frutalin is a heterogeneous mixture of several isoforms possibly with distinct biological activities. The main problem of using such lectins as biomedical tools is that batch-to-batch variation in isoforms content may lead to inconstant results. The production of lectins by recombinant means has the advantage of obtaining high amounts of proteins with defined amino-acid sequences and more precise properties. In this mini review, we provide the strategies followed to produce two different forms of frutalin in two different microbial systems: Escherichia coli and Pichia pastoris. The processing and functional properties of the recombinant frutalin obtained from these hosts are compared to those of frutalin extracted from breadfruit. Emphasis is given particularly to recombinant frutalin produced in P. pastoris, which showed a remarkable capacity as biomarker of human prostate cancer and as apoptosis-inducer of cancer cells. Recombinant frutalin production opens perspectives for its development as a new tool in human medicine.

Recombinant production of plant lectins in microbial systems for biomedical application – the frutalin case study

Science.gov (United States)

Oliveira, Carla; Teixeira, José A.; Domingues, Lucília

2014-01-01

Frutalin is a homotetrameric partly glycosylated α-D-galactose-binding lectin of biomedical interest from Artocarpus incisa (breadfruit) seeds, belonging to the jacalin-related lectins family. As other plant lectins, frutalin is a heterogeneous mixture of several isoforms possibly with distinct biological activities. The main problem of using such lectins as biomedical tools is that “batch-to-batch” variation in isoforms content may lead to inconstant results. The production of lectins by recombinant means has the advantage of obtaining high amounts of proteins with defined amino-acid sequences and more precise properties. In this mini review, we provide the strategies followed to produce two different forms of frutalin in two different microbial systems: Escherichia coli and Pichia pastoris. The processing and functional properties of the recombinant frutalin obtained from these hosts are compared to those of frutalin extracted from breadfruit. Emphasis is given particularly to recombinant frutalin produced in P. pastoris, which showed a remarkable capacity as biomarker of human prostate cancer and as apoptosis-inducer of cancer cells. Recombinant frutalin production opens perspectives for its development as a new tool in human medicine. PMID:25152749

Upgrading wholesomeness of soybeans through radiation deactivation of toxic lectin content

International Nuclear Information System (INIS)

Farag, D.M.

1994-01-01

The biological effects of raw soybeans were investigated through feeding experiments on rats and the wholesomeness of soybeans after radiation deactivation of toxic lectin present in seeds has been evaluated. The injection of crude lectins extracted from 0.15 g raw soybean by intraperitoneal route was toxic to rats (120-125 g body weight) and caused death within 24 hour while lectins extracted from irradiated beans showed no lethal effect. Administration of 28% raw beans diet as the sole protein in balanced diet caused strong growth depression in young rats. Radiation treatment corrects poor growth but did not prevent liver and stomach hypertrophy. No significant differences in relative organs body weight, between groups fed irradiated soybeans and casein diet were observed, except for an increased relative lever and stomach weights with group fed irradiated beans. Rats which received raw beans in their diet suffered from pancreatic, liver, stomach, testes and kidney hypertrophy and spleen atrophy. Data obtained on certain blood plasma chemical constituents (total plasma protein creatine, creatinine) revealed no significant difference between the control and experimental groups. 4 tabs

Low mannose-binding lectin serum levels are associated with reduced kidney graft survival

DEFF Research Database (Denmark)

Bay, Jakob Thaning; Sørensen, Søren S; Hansen, Jesper M

2013-01-01

Activation of the complement system is initiated by the alternative, the classical, or the lectin pathway. As the complement system is involved in the pathophysiology of graft rejection after kidney transplantation, we investigated the possible role of mannose-binding lectin in kidney transplanta...... immunity in maintaining kidney graft survival, but these are probably overruled by HLA immunization.Kidney International advance online publication, 21 November 2012; doi:10.1038/ki.2012.373....

Vitelline coat of Unio elongatulus: III. Glycan chain analysis of the 220- and 180-kD components by means of lectins.

Science.gov (United States)

Focarelli, R; Leotta, F; Lampariello, R; Rosati, F

1995-02-01

Lectins of different binding specificity were used to analyze the oligosaccharide chains of the 220- and 180-kD proteins of the Unio elongatulus egg vitelline coat (vc). The lectins ConA and RCA1 reacted with both glycoproteins, and four other lectins reacted with one or other vc components. The lectin from Galanthus nivalis, which recognizes terminal mannose residues of N-linked high mannose type oligosaccharide chains, bound specifically to the 180-kD protein. Binding sites for this lectin were found throughout the vc of the differentiating oocyte and the mature egg. Lectins specific for the O-linked oligosaccharide chains, such as AIA and PNA, reacted only with the 220-kD protein species. Binding sites for these lectins were found only in the crater region. The presence of fucosyl residues on the glycan chains was investigated with lectins from Lotus tetragonolobus and Aleuria aurantia. The latter was positive on both glycoproteins, whereas LTA was only positive to the 220-kD species. The binding sites of both these lectins were in the same areas as those of PNA and AIA. These results suggest that while the 180-kD protein is part of the entire vc structure, the 220-kD protein is prevalently accumulated in the crater region. Since this is where sperm recognition and interaction take place, it has been suggested the 220-kD protein acts as a ligand molecule in the sperm-egg interaction.

A simple procedure for the isolation of L-fucose-binding lectins from Ulex europaeus and Lotus tetragonolobus.

Science.gov (United States)

Allen, H J; Johnson, E A

1977-10-01

L-Fucose-binding lectins from Ulex europeaus and Lotus tetragonolobus were isolated by affinity chromatography on columns of L-fucose-Sepharose 6B. L-Fucose was coupled to Sepharose 6B after divinyl sulfone-activation of the gel to give an affinity adsorbent capable of binding more than 1.2 mg of Ulex lextin/ml of gel, which could then be eluted with 0.1M or 0.05M L-fucose. Analysis of the isolated lectins by hemagglutination assay, by gel filtration, and polyacrylamide disc-electrophoresis revealed the presence of isolectins, or aggregated species, or both. The apparent mol. wt. of the major lectin fraction from Lotus was 35000 when determined on Sephadex G-200 or Ultrogel AcA 34. In contrast, the apparent mol. wt. of the major lectin fraction from Ulex was 68 000 when chromatographed on Sephadex G-200 and 45 000 when chromatographed on Ultrogel AcA 34. The yields of lectins were 4.5 mg/100 g of Ulex seeds and 394 mg/100 g of Lotus seeds.

Histochemistry of lectin-binding sites in Halicryptus spinulosus (Priapulida).

Science.gov (United States)

Busch, A; Schumacher, U; Storch, V

2001-02-01

Priapulida represent one of the phylogenetically oldest multicellular animal groups. In multicellular animals (Metazoa) cell-to-cell and cell-to-matrix interactions are often mediated by carbohydrate residues of glycoconjugates. To analyze the carbohydrate composition of a phylogenetically old species, lectin histochemistry was employed on 5 specimens of the priapulid Halicryptus spinulosus. Many lectins bound to the chitin-containing cuticle, including those specific for carbohydrates other than N-acetylglucosamine, the principle building block of chitin. The connective tissue of the animals contained both N-acetylglucosamine and N-acetylgalactosamine. Mannose residues were widely distributed with the exception of the cuticle, but complex type carbohydrates were not present in the entire animal. Sialic acid residues were only detected in the cuticle and brush border of the intestinal epithelium, while fucose was limited to the cuticle. Thus, the lectin-binding pattern indicated that sugars typical for the linking region of both N- and O-glycoproteins in mammals are also present in H. spinulosus. Carbohydrate residues that are typical for the complex type of N-linked glycans in vertebrates are not present as are carbohydrate residues typical for the termination of O-linked carbohydrate chains. Hence, a truncated form of both N- and O-linked glycosylation is present in H. spinulosus indicating that more complex patterns of glycosylation developed later during evolution.

Antiproliferative activity of cytotoxic tuber lectins from Solanum ...

African Journals Online (AJOL)

SAM

2014-04-09

Apr 9, 2014 ... E-mail: hasanimtiaj@yahoo.co.uk, rashelkabir@ru.ac.bd. .... blue and then counted by a hemocytometer under an inverted microscope (XDS-1R .... and lectin-treated mice counted by a light microscope on day. 6 of tumor ...

The lectin pathway of complement activation is a critical component of the innate immune response to pneumococcal infection

DEFF Research Database (Denmark)

Ali, Youssif M; Lynch, Nicholas J; Haleem, Kashif S

2012-01-01

The complement system plays a key role in host defense against pneumococcal infection. Three different pathways, the classical, alternative and lectin pathways, mediate complement activation. While there is limited information available on the roles of the classical and the alternative activation...... to pneumococcal infection and fail to opsonize Streptococcus pneumoniae in the none-immune host. This defect in complement opsonisation severely compromises pathogen clearance in the lectin pathway deficient host. Using sera from mice and humans with defined complement deficiencies, we demonstrate that mouse...... of C4. This study corroborates the essential function of MASP-2 in the lectin pathway and highlights the importance of MBL-independent lectin pathway activation in the host defense against pneumococci....

Direct demonstration of the lectin activity of gp90MEL, a lymphocyte homing receptor

Science.gov (United States)

1990-01-01

Considerable evidence implicates gp90MEL as a lymphocyte homing receptor mediating lymphocyte attachment to high endothelial venules of lymph nodes in mouse. The protein appears to function as a calcium- dependent, lectin-like receptor as inferred primarily by the ability of specific carbohydrates to block its function and by the presence of a calcium-type lectin domain in its primary sequence. An ELISA assay is described which provides the first demonstration that the isolated protein has lectin activity and allows a further definition of its carbohydrate specificity. In addition to the monosaccharides mannose-6- phosphate and fructose-1-phosphate, ligand activity is shown for the sulfated glycolipid, sulfatide, and for two sulfated fucose-containing polysaccharides (fucoidin and egg jelly coat) from nonmammalian sources. PMID:2202735

Inactivation and fragmentation of lectin from Bothrops leucurus snake venom by gamma irradiation

International Nuclear Information System (INIS)

Nunes, E.S.; Souza, M.A.A.; Vaz, A.F.M.; Coelho, L.C.B.B.; Aguiar, J.S.; Silva, T.G.; Guarnieri, M.C.; Melo, A.M.M.A.; Oliva, M.L.V.; Correia, M.T.S.

2012-01-01

Gamma radiation alters the molecular structure of biomolecules and is able to mitigate the action of snake venoms and their isolated toxins. The effect of γ-radiation on the folding of Bothrops lecurus venom lectin was measured by a hemagglutinating assay, intrinsic and bis-ANS fluorescence. Intrinsic and bis-ANS fluorescence analyses indicated that irradiation caused unfolding followed by aggregation of the lectin. Our results suggest that irradiation can lead to significant changes in the protein structure, which may promote the loss of its binding property and toxic action. - Highlights: ► Gamma radiation alters the molecular structure of biomolecules. ► The radiation has been able to mitigate snake venoms and its isolated toxins. ► Our aim was to evaluate the effects of radiation in Bothrops lecurus venom lectin. ► The irradiation acts as a detoxification strategy in snake venoms.

Soybean Lectin Enhances Biofilm Formation by Bradyrhizobium japonicum in the Absence of Plants

Directory of Open Access Journals (Sweden)

Julieta Pérez-Giménez

2009-01-01

Full Text Available Soybean lectin (SBL purified from soybean seeds by affinity chromatography strongly bound to Bradyrhizobium japonicum USDA 110 cell surface. This lectin enhanced biofilm formation by B. japonicum in a concentration-dependent manner. Presence of galactose during biofilm formation had different effects in the presence or absence of SBL. Biofilms were completely inhibited in the presence of both SBL and galactose, while in the absence of SBL, galactose was less inhibitory. SBL was very stable, since its agglutinating activity of B. japonicum cells as well as of human group A+ erythrocytes was resistant to preincubation for one week at 60°C. Hence, we propose that plant remnants might constitute a source of this lectin, which might remain active in soil and thus favor B. japonicum biofilm formation in the interval between soybean crop seasons.

An Ixodes ricinus Tick Salivary Lectin Pathway Inhibitor Protects Borrelia burgdorferi sensu lato from Human Complement

NARCIS (Netherlands)

Wagemakers, Alex; Coumou, Jeroen; Schuijt, Tim J.; Oei, Anneke; Nijhof, Ard M.; van 't Veer, Cornelis; van der Poll, Tom; Bins, Adriaan D.; Hovius, Joppe W. R.

2016-01-01

We previously identified tick salivary lectin pathway inhibitor (TSLPI) in Ixodes scapularis, a vector for Borrelia burgdorferi sensu stricto (s.s.) in North America. TSLPI is a salivary protein facilitating B. burgdorferi s.s. transmission and acquisition by inhibiting the host lectin complement

[Separation of osteoclasts by lectin affinity chromatography].

Science.gov (United States)

Itokazu, M; Tan, A; Tanaka, S

1991-09-01

Newborn rat calvaria bone cells obtained by digestion were fractionated on columns of wheat-germ agglutinin (WGA) sepharose 6MB for osteoclast isolation. The initial nonspecific binding cells which were passed through the WGA sepharose column by a buffer acquired a high enzyme activity of alkaline phosphatase, but not that of acid phosphatase. However, elution of cells using a buffer with the addition of N-acetyl-D-glucosamine resulted in a high acid phosphatase activity but no alkaline phosphatase activity. The former WGA binding negative fraction enriched osteoblasts averaging 30 microns in size. The latter WGA binding positive fraction enriched osteoclasts ranging from 20 microns to 60 microns in size. The electron-microscope clearly demonstrated the cellular details of osteoclasts. Isolated cell counts showed a ratio of six to four. These results indicate that our method of osteoclast isolation is simple and useful in lectin affinity chromatography because all cells have sugar moieties on their surface and the binding of osteoclasts can be reversed by the addition of specific lectin-binding sugars to the eluting buffer.

Plant Lectins as Medical Tools against Digestive System Cancers

Directory of Open Access Journals (Sweden)

Laura Elena Estrada-Martínez

2017-07-01

Full Text Available Digestive system cancers—those of the esophagus, stomach, small intestine, colon-rectum, liver, and pancreas—are highly related to genetics and lifestyle. Most are considered highly mortal due to the frequency of late diagnosis, usually in advanced stages, caused by the absence of symptoms or masked by other pathologies. Different tools are being investigated in the search of a more precise diagnosis and treatment. Plant lectins have been studied because of their ability to recognize and bind to carbohydrates, exerting a variety of biological activities on animal cells, including anticancer activities. The present report integrates existing information on the activity of plant lectins on various types of digestive system cancers, and surveys the current state of research into their properties for diagnosis and selective treatment.

Measurement of Skin Permeation/Penetration of Nanoparticles for Their Safety Evaluation

OpenAIRE

木村, 恵理子; 河野, 雄一郎; 藤堂, 浩明; 五十嵐, 良明; 杉林, 堅次

2012-01-01

The aim of the present study was to quantitatively evaluate the skin permeation/penetration of nanomaterials and to consider their penetration pathway through skin. Firstly, penetration/permeation of a model fluorescent nanoparticle, Fluoresbrite?, was determined through intact rat skin and several damaged skins. Fluoresbrite? permeated through only needle-punctured skin. The permeation profiles of soluble high molecular compounds, fluorescein isothiocyanate-dextrans (FITC-dextrans, FDs), wit...

Inhibition of initial adhesion of oral bacteria through a lectin from Bauhinia variegata L. var. variegata expressed in Escherichia coli.

Science.gov (United States)

Klafke, G B; Borsuk, S; Gonçales, R A; Arruda, F V S; Carneiro, V A; Teixeira, E H; Coelho da Silva, A L; Cavada, B S; Dellagostin, O A; Pinto, L S

2013-11-01

The aim of the present work was to study the in vitro effect of native and recombinant Bauhinia variegata var. variegata lectins in inhibiting early adhesion of Streptococcus mutans, Streptococcus sanguis and Streptococcus sobrinus to experimentally acquired pellicle. Native lectin from B. variegata (BVL) was purified by affinity chromatography of extract of seeds. The recombinant lectin (rBVL-I) was expressed in E. coli strain BL21 (DE3) from a genomic clone encoding the mature B. variegata lectin gene using the vector pAE-bvlI. Recombinant protein deposited in inclusion bodies was solubilized and subsequently purified by affinity chromatography. The rBVL-I was compared to BVL for agglutination of erythrocytes and initial adherence of oral bacteria on a saliva-coated surface. The results revealed that rBVL-I acts similarly to BVL for agglutination of erythrocytes. Both lectins showed adhesion inhibition effect on Step. sanguis, Step. mutans and Step. sobrinus. We report, for the first time, the inhibition of early adhesion of oral bacteria by a recombinant lectin. Our results support the proposed biotechnological application of lectins in a strategy to reduce development of dental caries by inhibiting the initial adhesion and biofilm formation. © 2013 The Society for Applied Microbiology.

[Inhibition by cysteine of the carbohydrate-binding activity of lectins from Ricinus communis, Canavalia ensiformis and Euonymus europaeus].

Science.gov (United States)

Dvorkin, V M

1985-10-01

Precipitation induced by different lectins has been studied in the presence of some aminoacids. It was shown that precipitates formed by lectins from Ricinus communis (RCA1), Canavalia ensiformis (Con A), Euonymus europaeus (Eel) in the presence of appropriate carbohydrate-containing molecules disappeared after cysteine addition, like after addition of specific carbohydrate precipitation inhibitors. It is assumed that cysteine residues of RCA1, Con A and Eel lectins are essential for their carbohydrate binding activity.

A new mannose-specific lectin from daylily (Hemerocallis fulva L. rhizome: purification and properties

Directory of Open Access Journals (Sweden)

V. O. Antonyuk

2013-04-01

Full Text Available A new lectin was purified from the daylily (Hemerocallis fulva L. with the yield of approximately 10 mg per kg of fresh plant rhizome. The purification procedure was based on application of the affinity chromathography on the column with yeast mannan and the ion-exchange chromatography on the column with DEAE-Toyopearl. The lectin possessed low affinity for α-methyl-D-mannopyranoside, D-fructose, D-turanose and 2-acetamido-D-galactopyranose and hight affinity for the yeast mannan. The lectin bound with greatly less affinity for the mannose-containig glycoproteins, such as ovoalbumin, ovomucoid and horseradish peroxidase. According to the results of electrophoresis in 20% DSNa-PAGE, the lectin consists of subunits of 12 kDa molecular weight. According to the results of gel-chromatography on the Toyopearl HW-55, the lectin’s molecular weight is 48 kDa. It agglutinated rabbit erythrocytes very well, while rat and guinea-pig erythrocytes were agglutinated worse, and human erythrocytes were not agglutinated at all. Lectin’s dialysis against 1% EDTA or heating to 60 ºC for 60 min did not stop its hemagglutinating activity.

Galactose-binding lectin from mulberry (Morus alba L. seeds with growth hormone-like activity

Directory of Open Access Journals (Sweden)

E. Khurtsidze

2017-03-01

Full Text Available Plant lectins are well documented to participate in multiple physiological activities based on selective binding to the carbohydrate structures. They have been reported to play significant roles in various processes such as growth and development, differentiation and plant protection. Nevertheless, the intrinsic roles of plant lectins still remain undefined. We purified a galactose-binding lectin, named MAL, from mulberry (M. alba L. seeds and analyzed its properties. The lectin is composed of one polypeptide of 17 kDa, which is abundant in the seed protein fraction. MAL interacted with GalNAc and galactose residues of saccharides with high binding ability. Western blotting analysis suggested that MAL is deposited in the mulberry leaves and inflorescence. MAL was examined for growth stimulatory activity on mulberry hypocotyls and internodal sections of in vitro grown P. euphratica cultures. Elongation of mulberry hypocotyls was detected in the apical parts of the hypocotyl, where the growth increment was 58%. MAL had no significant effect on the stem elongation and induction of new leaves. Our results suggest that MAL may be involved in the growth and cell elongation at initial stages of tissue development.

Mannan-binding lectin is involved in the protection against renal ischemia/ reperfusion injury by dietary restriction

NARCIS (Netherlands)

Shushimita; P. van der Pol (Pieter); R.W.F. de Bruin (Ron); J.N.M. IJzermans (Jan); C. van Kooten (Cees); F.J.M.F. Dor (Frank)

2015-01-01

textabstractPreoperative fasting and dietary restriction offer robust protection against renal ischemia/ reperfusion injury (I/RI) in mice.We recently showed that Mannan-binding lectin (MBL), the initiator of the lectin pathway of complement activation, plays a pivotal role in renal I/RI. Based on

Severe blood-brain barrier disruption and surrounding tissue injury.

Science.gov (United States)

Chen, Bo; Friedman, Beth; Cheng, Qun; Tsai, Phil; Schim, Erica; Kleinfeld, David; Lyden, Patrick D

2009-12-01

Blood-brain barrier opening during ischemia follows a biphasic time course, may be partially reversible, and allows plasma constituents to enter brain and possibly damage cells. In contrast, severe vascular disruption after ischemia is unlikely to be reversible and allows even further extravasation of potentially harmful plasma constituents. We sought to use simple fluorescent tracers to allow wide-scale visualization of severely damaged vessels and determine whether such vascular disruption colocalized with regions of severe parenchymal injury. Severe vascular disruption and ischemic injury was produced in adult Sprague Dawley rats by transient occlusion of the middle cerebral artery for 1, 2, 4, or 8 hours, followed by 30 minutes of reperfusion. Fluorescein isothiocyanate-dextran (2 MDa) was injected intravenously before occlusion. After perfusion-fixation, brain sections were processed for ultrastructure or fluorescence imaging. We identified early evidence of tissue damage with Fluoro-Jade staining of dying cells. With increasing ischemia duration, greater quantities of high molecular weight dextran-fluorescein isothiocyanate invaded and marked ischemic regions in a characteristic pattern, appearing first in the medial striatum, spreading to the lateral striatum, and finally involving cortex; maximal injury was seen in the mid-parietal areas, consistent with the known ischemic zone in this model. The regional distribution of the severe vascular disruption correlated with the distribution of 24-hour 2,3,5-triphenyltetrazolium chloride pallor (r=0.75; P<0.05) and the cell death marker Fluoro-Jade (r=0.86; P<0.05). Ultrastructural examination showed significantly increased areas of swollen astrocytic foot process and swollen mitochondria in regions of high compared to low leakage, and compared to contralateral homologous regions (ANOVA P<0.01). Dextran extravasation into the basement membrane and surrounding tissue increased significantly from 2 to 8 hours of

Lectin immunohistochemical evaluation of human bladder carcinomas. A comparison of Carnoy's and formalin fixation.

Science.gov (United States)

Okamura, T; Ueda, K; Ohtaguro, K; Inoue, K; Washida, H; Mori, M; Tatemoto, Y; Fukushima, S

1993-10-01

A lectin immunohistochemical analysis of 51 human bladder carcinomas, including 44 cases of transitional cell carcinoma (TCC) (G1, 15 cases; G2, 17 cases; G3, 12 cases) and 7 cases of squamous cell carcinoma (SCC), was performed. Tissues were obtained by cold punch biopsies, fixed in Carnoy's or 10% formalin solution, stained for binding of 10 different lectins, and evaluated under the light microscope. The lectins used were concanavalin agglutinin (Con A), soybean agglutinin (SBA), Lotus tetragonolobus agglutinin (LTA), Dolichos biflorusa agglutinin (DBA), peanut agglutinin (PNA), Ricinus communis agglutinin I (RCA1), Ulex europaeus agglutinin I, II (UEA-I, II), wheat germ agglutinin (WGA), and Pisum sativum agglutinin (PEA). TCC prepared with Carnoy's fixation tended to show moderately positive Con A, UEA-I, and WGA reactions for G1, and strongly positive reactions for G2 and G3 lesions. UEA-II was mainly negative in G1, but tended to increase to become moderate in G3. DBA tended to show a moderately positive reaction in G1 and G2, but was mainly negative in G3. With formalin fixation, only RCA1 demonstrated grade specific variation, tendency to react moderately in the G1 and G2 cases, and strongly in G3. There were no further differences among the histopathological grades of TCC for other lectins. Thus, Carnoy's fixation appears superior for distinguishing between grades of lesions. SCC tended to react more strongly than TCC with all the various lectins except PEA, independent of fixation.

Purification, crystallization and preliminary X-ray structure analysis of the banana lectin from Musa paradisiaca.

Science.gov (United States)

Singh, D D; Saikrishnan, K; Kumar, Prashant; Dauter, Z; Sekar, K; Surolia, A; Vijayan, M

2004-11-01

The banana lectin from Musa paradisiaca, MW 29.4 kDa, has been isolated, purified and crystallized. The trigonal crystals contain one dimeric molecule in the asymmetric unit. The structure has been solved using molecular replacement to a resolution of 3 A. The structure of the subunit is similar to that of jacalin-like lectins.

The addition of organotin hydrides to isocyanates and isothiocyanates: synthesis and structure of some organotin-substituted amides

NARCIS (Netherlands)

Noltes, J.G.; Janssen, M.J.

Organotin hydrides add across the carbon---nitrogen double bond of aryl isocyanates (tin---nitrogen bond formation) and hexyl isocyanate (tin---carbon bond formation) and across the carbon---sulfur double bond of phenyl isothiocyanate (tin---sulfur bond formation) to afford in excellent yield 1:1

Radiation enhances shelf life of Nendra bananas without changing the lectin content of raw and steamed Nendra banana

International Nuclear Information System (INIS)

Coelho, Neil Renault; Nivas, Shashikiran; D'Souza, L.

2016-01-01

Our study shows that the shelf life of bananas is increased with low doses of radiation (300 Gy, 400 Gy, 500 Gy). However, there is no decrease in the lectin content. This improves the keeping quality of nendra bananas without affecting their lectin content. Hence, radiation can be used safely for the bananas distributed to HIV children. The present study was also to compare the lectin content of raw and steamed Nendra bananas with the gamma irradiated bananas

Structural characterization of coagulant Moringa oleifera Lectin and its effect on hemostatic parameters.

Science.gov (United States)

Luz, Luciana de Andrade; Silva, Mariana Cristina Cabral; Ferreira, Rodrigo da Silva; Santana, Lucimeire Aparecida; Silva-Lucca, Rosemeire Aparecida; Mentele, Reinhard; Oliva, Maria Luiza Vilela; Paiva, Patricia Maria Guedes; Coelho, Luana Cassandra Breitenbach Barroso

2013-07-01

Lectins are carbohydrate recognition proteins. cMoL, a coagulant Moringa oleifera Lectin, was isolated from seeds of the plant. Structural studies revealed a heat-stable and pH resistant protein with 101 amino acids, 11.67 theoretical pI and 81% similarity with a M. oleifera flocculent protein. Secondary structure content was estimated as 46% α-helix, 12% β-sheets, 17% β-turns and 25% unordered structures belonging to the α/β tertiary structure class. cMoL significantly prolonged the time required for blood coagulation, activated partial thromboplastin (aPTT) and prothrombin times (PT), but was not so effective in prolonging aPTT in asialofetuin presence. cMoL acted as an anticoagulant protein on in vitro blood coagulation parameters and at least on aPTT, the lectin interacted through the carbohydrate recognition domain. Copyright © 2013 Elsevier B.V. All rights reserved.

Net Fluorescein Flux Across Corneal Endothelium Strongly Suggests Fluid Transport is due to Electro-osmosis.

Science.gov (United States)

Sanchez, J M; Cacace, V; Kusnier, C F; Nelson, R; Rubashkin, A A; Iserovich, P; Fischbarg, J

2016-08-01

We have presented prior evidence suggesting that fluid transport results from electro-osmosis at the intercellular junctions of the corneal endothelium. Such phenomenon ought to drag other extracellular solutes. We have investigated this using fluorescein-Na2 as an extracellular marker. We measured unidirectional fluxes across layers of cultured human corneal endothelial (HCE) cells. SV-40-transformed HCE layers were grown to confluence on permeable membrane inserts. The medium was DMEM with high glucose and no phenol red. Fluorescein-labeled medium was placed either on the basolateral or the apical side of the inserts; the other side carried unlabeled medium. The inserts were held in a CO2 incubator for 1 h (at 37 °C), after which the entire volume of the unlabeled side was collected. After that, label was placed on the opposite side, and the corresponding paired sample was collected after another hour. Fluorescein counts were determined with a (Photon Technology) DeltaScan fluorometer (excitation 380 nm; emission 550 nm; 2 nm bwth). Samples were read for 60 s. The cells utilized are known to transport fluid from the basolateral to the apical side, just as they do in vivo in several species. We used 4 inserts for influx and efflux (total: 20 1-h periods). We found a net flux of fluorescein from the basolateral to the apical side. The flux ratio was 1.104 ± 0.056. That difference was statistically significant (p = 0.00006, t test, paired samples). The endothelium has a definite restriction at the junctions. Hence, an asymmetry in unidirectional fluxes cannot arise from osmosis, and can only point instead to paracellular solvent drag. We suggest, once more, that such drag is due to electro-osmotic coupling at the paracellular junctions.

Safety testing of GM-rice expressing PHA-E lectin using a new animal test design

DEFF Research Database (Denmark)

Poulsen, Morten; Schrøder, Malene; Wilcks, Andrea

2007-01-01

The 90-day animal study is the core study for the safety assessment of genetically modified foods in the SAFOTEST project. The model compound tested in the 90-day study was a rice variety expressing the kidney bean Phaseolus vulgaris lectin agglutinin E-form (PHA-E lectin). Female Wistar rats were...... safety testing of genetically modified foods....

Polycaprolactone/maltodextrin nanocarrier for intracellular drug delivery: formulation, uptake mechanism, internalization kinetics, and subcellular localization.

Science.gov (United States)

Korang-Yeboah, Maxwell; Gorantla, Yamini; Paulos, Simon A; Sharma, Pankaj; Chaudhary, Jaideep; Palaniappan, Ravi

2015-01-01

Prostate cancer (PCa) disease progression is associated with significant changes in intracellular and extracellular proteins, intracellular signaling mechanism, and cancer cell phenotype. These changes may have direct impact on the cellular interactions with nanocarriers; hence, there is the need for a much-detailed understanding, as nanocarrier cellular internalization and intracellular sorting mechanism correlate directly with bioavailability and clinical efficacy. In this study, we report the differences in the rate and mechanism of cellular internalization of a biocompatible polycaprolactone (PCL)/maltodextrin (MD) nanocarrier system for intracellular drug delivery in LNCaP, PC3, and DU145 PCa cell lines. PCL/MD nanocarriers were designed and characterized. PCL/MD nanocarriers significantly increased the intracellular concentration of coumarin-6 and fluorescein isothiocyanate-labeled bovine serum albumin, a model hydrophobic and large molecule, respectively. Fluorescence microscopy and flow cytometry analysis revealed rapid internalization of the nanocarrier. The extent of nanocarrier cellular internalization correlated directly with cell line aggressiveness. PCL/MD internalization was highest in PC3 followed by DU145 and LNCaP, respectively. Uptake in all PCa cell lines was metabolically dependent. Extraction of endogenous cholesterol by methyl-β-cyclodextrin reduced uptake by 75%±4.53% in PC3, 64%±6.01% in LNCaP, and 50%±4.50% in DU145, indicating the involvement of endogenous cholesterol in cellular internalization. Internalization of the nanocarrier in LNCaP was mediated mainly by macropinocytosis and clathrin-independent pathways, while internalization in PC3 and DU145 involved clathrin-mediated endocytosis, clathrin-independent pathways, and macropinocytosis. Fluorescence microscopy showed a very diffused and non-compartmentalized subcellular localization of the PCL/MD nanocarriers with possible intranuclear localization and minor colocalization in

Immunotoxicological studies of genetically modified rice expressing PHA-E lectin or Bt toxin in Wistar rats

DEFF Research Database (Denmark)

Kroghsbo, Stine; Madsen, Charlotte Bernhard; Poulsen, Morten

2008-01-01

As part of the SAFOTEST project the immunmodulating effect of Cry1Ab protein from Bacillus thuringiensis (Bt) and PHA-E lectin from kidney bean (Phaseolus vulgaris erythroagglutinin) was examined in 28- and 90-day feeding studies in Wistar rats. PHA-E lectin was chosen as positive control. Rats...

Mannose-binding lectin impairs Leptospira activity through the inhibitory effect on the motility of cell.

Science.gov (United States)

Xu, Jun; Guo, Yijie; Nakamura, Shuichi; Islam, Md Shafiqul; Tomioka, Rintaro; Yoneyama, Hiroshi; Isogai, Emiko

2015-02-01

Mannose-binding lectin (MBL) plays key role in lectin pathway of innate immunity, and shows the ability of triggering opsonization intermediately. Substantial increase in the serum level of MBL has been confirmed during leptospirosis, which caused by a pathogenic spirochete, Leptospira. Leptospira has a fascinating locomotion pattern, which simultaneously gyrating and swimming forward, such motility enables that Leptospira is difficult to be captured by immune cells if without any assistance. In this study, the effect of mannose-binding lectin to Leptospira was quantitatively investigated by measuring some kinematic parameters, to discover the mechanism behind MBL-mediated immune responses during leptospiral infection. The results showed that mannose-binding lectin is capable of inhibiting the motility of Leptospira by transforming free swimming cells to tumbled rotating cells, resulted in the increase number of rotating cells. Otherwise, decrease in rotation rate of rotating cell has been observed. However, the swimming speed of swimming Leptospira cells showed no observable change under the effect of MBL. The inhibitory effect were only valid in a relatively short period, Leptospira cells regained their original motility after 2 h. This raises an interesting topic that Leptospira is somehow able to escape from the inhibitory effect of MBL by dragging such unfavorable molecules toward to the cell end and eventually throwing it out. The inhibitory effect of MBL on the motility of Leptospira is expected to provide a new insight into lectin pathway. Copyright © 2015 Elsevier GmbH. All rights reserved.

Correlation of quinone reductase activity and allyl isothiocyanate formation among different genotypes and grades of horseradish roots.

Science.gov (United States)

Ku, Kang-Mo; Jeffery, Elizabeth H; Juvik, John A; Kushad, Mosbah M

2015-03-25

Horseradish (Armoracia rusticana) is a perennial crop and its ground root tissue is used in condiments because of the pungency of the glucosinolate (GS)-hydrolysis products allyl isothiocyanate (AITC) and phenethyl isothiocyanate (PEITC) derived from sinigrin and gluconasturtiin, respectively. Horseradish roots are sold in three grades: U.S. Fancy, U.S. No. 1, and U.S. No. 2 according to the USDA standards. These grading standards are primarily based on root diameter and length. There is little information on whether root grades vary in their phytochemical content or potential health promoting properties. This study measured GS, GS-hydrolysis products, potential anticancer activity (as quinone reductase inducing activity), total phenolic content, and antioxidant activities from different grades of horseradish accessions. U.S. Fancy showed significantly higher sinigrin and AITC concentrations than U.S. No. 1 ,whereas U.S. No. 1 showed significantly higher concentrations of 1-cyano 2,3-epithiopropane, the epithionitrile hydrolysis product of sinigrin, and significantly higher total phenolic concentrations than U.S. Fancy.

Knowledge-based modeling of a legume lectin and docking of the carbohydrate ligand: the Ulex europaeus lectin I and its interaction with fucose.

Science.gov (United States)

Gohier, A; Espinosa, J F; Jimenez-Barbero, J; Carrupt, P A; Pérez, S; Imberty, A

1996-12-01

Ulex europaeus isolectin I is specific for fucose-containing oligosaccharide such as H type 2 trisaccharide alpha-L-Fuc (1-->2) beta-D-Gal (1-->4) beta-D-GlcNAc. Several legume lectins have been crystallized and modeled, but no structural data are available concerning such fucose-binding lectin. The three-dimensional structure of Ulex europaeus isolectin I has been constructed using seven legume lectins for which high-resolution crystal structures were available. Some conserved water molecules, as well as the structural cations, were taken into account for building the model. In the predicted binding site, the most probable locations of the secondary hydroxyl groups were determined using the GRID method. Several possible orientations could be determined for a fucose residue. All of the four possible conformations compatible with energy calculations display several hydrogen bonds with Asp-87 and Ser-132 and a stacking interaction with Tyr-220 and Phe-136. In two orientations, the O-3 and O-4 hydroxyl groups of fucose are the most buried ones, whereas two other, the O-2 and O-3 hydroxyl groups are at the bottom of the site. Possible docking modes are also studied by analysis of the hydrophobic and hydrophilic surfaces for both the ligand and the protein. The SCORE method allows for a quantitative evaluation of the complementarity of these surfaces, on the basis of molecular lipophilicity calculations. The predictions presented here are compared with known biochemical data.

Effects of plant lectin from cobra lily, Arisaema curvatum Kunth on development of melon fruit fly, Bactrocera cucurbitae (Coq.).

Science.gov (United States)

Singh, Kuljinder; Kaur, Manpreet; Rup, Pushpinder J; Singh, Jatinder

2008-11-01

The lectin from tubers of cobra lily, Arisaema curvatum Kunth was purified by affinity chromatography using asialofetuin-linked amino activated porous silica beads. The concentration dependent effect of lectin was studied on second instar larvae (64-72 hr) of Bactrocera cucurbitae (Coq.). The treatment not only resulted in a significant reduction in the percentage pupation and emergence of the adults from treated larvae but it also prolonged the remaining larval development period. A very low LC50 value, 39 mgl(-1) of lectin was obtained on the basis of adult emergence using probit analysis. The activity of three hydrolase enzymes (esterases, acid and alkaline phosphatases), one oxidoreductase (catalase) and one group transfer enzyme (GSTs: Glutathione S-transferases) was assayed in second instar larvae under the influence of the LC50 of lectin at increasing exposure intervals (0, 24, 48 and 72 hr). The Arisaema curvatum lectin significantly decreased the activity of all the enzymes except for esterases, where the activity increased as compared to control at all exposure intervals. The decrease in pupation and emergence as well as significant suppression in the activities of two hydrolases, one oxidoreductase and one GST enzyme in treated larvae of B. cucurbitae indicated that this lectin has anti-metabolic effect on the melon fruit fly larvae.

A comparative study of three different synthesis routes for hydrophilic fluorophore-doped silica nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Shahabi, Shakiba [University of Bremen, Advanced Ceramics (Germany); Treccani, Laura, E-mail: treccani@petroceramics.com [Petroceramics S.p.A., Kilometro Rosso Science Park (Italy); Rezwan, Kurosch [University of Bremen, Advanced Ceramics (Germany)

2016-01-15

The synthesis of fluorophore-doped silica nanoparticles (FDS NPs) with two conventional approaches, Stöber and microemulsion, as well as a novel amino acid-catalyzed seeds regrowth technique (ACSRT) is presented. The efficiency of each applied synthesis route toward incorporation of selected hydrophilic fluorophores, including rhodamine B isothiocyanate and fluorescein isothiocyanate, without and with an amine-containing crosslinker, into silica matrix was systematically studied. Our results clearly highlight the advantages of ACSRT to obtain FDS NPs with a remarkable encapsulation efficiency, high quantum yield, and enhanced stability against bleaching and dye leaking due to efficient embedding of the dyes inside silica network even without the amine-containing silane reagent. Moreover, evaluation of photostability of FDNPs internalized in human bone cells demonstrates the merits of ACSRT.

Galactose/N-acetylgalactosamine lectin: the coordinator of host cell ...

Indian Academy of Sciences (India)

Unknown

Involvement of the lectin ... tion of the extra-cellular matrix (DeMeester et al 1990). The goal of this review is to ... E. histolytica molecules discovered that bind these resi- dues are the ..... Fas-dependent, non-tumor necrosis factor alpha depen-.

SL15: A seminal plasma-derived lectin from the sperm of llama (Lama glama).

Science.gov (United States)

Zampini, Renato; Sequeira, Sabrina; Argañaraz, Martin E; Apichela, Silvana A

2017-07-01

The oviductal sperm reservoir of South American camelids is formed when sperm bind to N-acetylgalactosamine (GalNAc) on the surface of oviductal epithelium. The aim of this study was to characterize the GalNAc-binding proteins on llama sperm, and to establish their origin. Sperm-adsorbed proteins were extracted with 0.5 M KCl in Hepes-balanced salts. Sperm-adsorbed and seminal plasma proteins were then subjected to ligand blotting for their GalNAc affinity, and the labeled bands were identified by mass spectrometry. Three proteins were identified in seminal plasma versus only one in the sperm-adsorbed population; SL15, a seminal lectin, was common to both. SL15 is a homologue of Zymogen granule protein 16, homolog B-like, which belongs to the Jacalin-related lectin family. This lectin is likely presented to sperm via seminal plasma since epididymal sperm are not capable of binding GalNAc, whereas ejaculated sperm does, and its transcript was enriched predominantly in the prostate and bulbourethral glands. This is the first report of a seminal lectin in South American camelids that originates in the male reproductive tract, and is probably involved in sperm reservoir formation. © 2017 Wiley Periodicals, Inc.

Therapeutic Efficacy of Allyl Isothiocyanate Evaluated on N-Nitrosodiethylamine/Phenobarbitol induced Hepatocarcinogenesis in Wistar Rats

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G. Thiyagarajan

2010-07-01

Full Text Available N-nitrosodiethylamine (NDEA is a potential carcinogenic agent that induces liver cancer. To evaluate the chemotherapeutic effect of Allyl isothiocyanate in the experimental model, Wistar male rats were administered single dose of intraperitoneal (IP injection of NDEA. Two weeks after administration of NDEA, Phenobarbital at the concentration of 0.05% was incorporated in rat chow for up to 14 successive weeks to promote liver cancer. Allyl isothiocyanate (AITC (2mg/kg body weight in addition with 0.5ml of corn oil was given orally on a daily basis. At the end of this experimental period, the rats were sacrificed and the blood samples were taken for biochemical studies. The levels of the marker enzymes for liver function were measured in serum. The results of the biochemical studies showed that NDEA administration followed by phenobarbital induces macro and microscopic liver tumors that increase the levels of marker enzymes and decreases the level of antioxidant in the serum in addition to loss of body weight. Conclusively, the administration of AITC as therapeutic treatment for hepatocarcinoma has significantly reduced the tumor development and counteracted all the biochemical effects induced by NDEA.

Inhibition of human immunodeficiency virus 1 (HIV-1) and herpes simplex virus 1 (HSV-1) infectivity with a broad range of lectins

DEFF Research Database (Denmark)

Hansen, J E; Nielsen, C; Vestergaard, B F

1991-01-01

Five lectins with specificity for N- and O-linked oligosaccharides were examined for inhibition of HIV-1 and HSV-1 infectivity in vitro. HIV-1 isolate HTLVIIIB was preincubated with lectin and subsequently inoculated onto MT-4 cells. Lectins specific for N-linked oligosaccharides blocked HIV infe...

Development of new apple beverages rich in isothiocyanates by using extracts obtained from ultrasound-treated cauliflower by-products

DEFF Research Database (Denmark)

Amofa-Diatuo, Tracy; Anang, Daniel M.; Barba Orellana, Francisco Jose

2017-01-01

The objective of this study was to develop a new apple juice beverage enriched with isothiocyanates (ITC) - rich extracts obtained from cauliflower by-products. Ultrasound-assisted extraction (UAE) at different amplitudes (20-100%) and extraction times (0-10. min) at a frequency of 24. kHz was em......The objective of this study was to develop a new apple juice beverage enriched with isothiocyanates (ITC) - rich extracts obtained from cauliflower by-products. Ultrasound-assisted extraction (UAE) at different amplitudes (20-100%) and extraction times (0-10. min) at a frequency of 24. k......) and UAE (20%, 3. min), respectively. Moreover, the highest recovery of total phenolic compounds (TPC) (≈105. mg gallic acid equivalent (GAE)/L) μM) was found after UAE (100% amplitude, 3. min) of TPC from stems. ITC-rich extracts obtained from caulifower by-products at the optimum UAE conditions were...

Selective binding and transcytosis of Ulex europaeus 1 lectin by mouse Peyer's patch M-cells in vivo.

Science.gov (United States)

Clark, M A; Jepson, M A; Simmons, N L; Hirst, B H

1995-12-01

The in vivo interaction of the lectin Ulex europaeus agglutinin 1 with mouse Peyer's patch follicle-associated epithelial cells was studied in the mouse Peyer's patch gut loop model by immunofluorescence and electron microscopy. The lectin targets to mouse Peyer's patch M-cells and is rapidly endocytosed and transcytosed. These processes are accompanied by morphological changes in the M-cell microvilli and by redistribution of polymerised actin. The demonstration of selective binding and uptake of a lectin by intestinal M-cells in vivo suggests that M-cell-specific surface glycoconjugates might act as receptors for the selective adhesion/uptake of microorganisms.

Structural insights into the anti-HIV activity of the Oscillatoria agardhii agglutinin homolog lectin family.

Science.gov (United States)

Koharudin, Leonardus M I; Kollipara, Sireesha; Aiken, Christopher; Gronenborn, Angela M

2012-09-28

Oscillatoria agardhii agglutinin homolog (OAAH) proteins belong to a recently discovered lectin family. All members contain a sequence repeat of ~66 amino acids, with the number of repeats varying among different family members. Apart from data for the founding member OAA, neither three-dimensional structures, information about carbohydrate binding specificities, nor antiviral activity data have been available up to now for any other members of the OAAH family. To elucidate the structural basis for the antiviral mechanism of OAAHs, we determined the crystal structures of Pseudomonas fluorescens and Myxococcus xanthus lectins. Both proteins exhibit the same fold, resembling the founding family member, OAA, with minor differences in loop conformations. Carbohydrate binding studies by NMR and x-ray structures of glycan-lectin complexes reveal that the number of sugar binding sites corresponds to the number of sequence repeats in each protein. As for OAA, tight and specific binding to α3,α6-mannopentaose was observed. All the OAAH proteins described here exhibit potent anti-HIV activity at comparable levels. Altogether, our results provide structural details of the protein-carbohydrate interaction for this novel lectin family and insights into the molecular basis of their HIV inactivation properties.

Multiplicity of carbohydrate-binding sites in β-prism fold lectins ...

Indian Academy of Sciences (India)

PRAKASH KUMAR

cancer metastasis, embryogenesis, tissue development and mitogenic stimulation ... within the sequence exhibit reasonable correlation. The distribution of the ..... II fold lectins with known structure in complex with sugar. Sugars are shown in ...

Integrative Lifecourse and Genetic Analysis of Military Working Dogs

Science.gov (United States)

2013-10-01

FITC) and Alexa Fluor 647 (BD Biosciences), respectively. Secondary antibodies of either phycoerythrin (PE; 5 μL) or fluorescein isothiocyanate (FITC; 1...zone B cells [2]. Cytokines/cytokine receptors, Ig recognition , and antigen presented by APCs, dendritic cells, and/or macrophages can initiate...MetaMap is targeted at finding medical terms from a biomedical text, it leverages a combination of part-of- speech tagging, shallow parsing, and longest

Engineering of PA-IIL lectin from Pseudomonas aeruginosa – Unravelling the role of the specificity loop for sugar preference

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Imberty Anne

2007-06-01

Full Text Available Abstract Background Lectins are proteins of non-immune origin capable of binding saccharide structures with high specificity and affinity. Considering the high encoding capacity of oligosaccharides, this makes lectins important for adhesion and recognition. The present study is devoted to the PA-IIL lectin from Pseudomonas aeruginosa, an opportunistic human pathogen capable of causing lethal complications in cystic fibrosis patients. The lectin may play an important role in the process of virulence, recognizing specific saccharide structures and subsequently allowing the bacteria to adhere to the host cells. It displays high values of affinity towards monosaccharides, especially fucose – a feature caused by unusual binding mode, where two calcium ions participate in the interaction with saccharide. Investigating and understanding the nature of lectin-saccharide interactions holds a great potential of use in the field of drug design, namely the targeting and delivery of active compounds to the proper site of action. Results In vitro site-directed mutagenesis of the PA-IIL lectin yielded three single point mutants that were investigated both structurally (by X-ray crystallography and functionally (by isothermal titration calorimetry. The mutated amino acids (22–23–24 triad belong to the so-called specificity binding loop responsible for the monosaccharide specificity of the lectin. The mutation of the amino acids resulted in changes to the thermodynamic behaviour of the mutants and subsequently in their relative preference towards monosaccharides. Correlation of the measured data with X-ray structures provided the molecular basis for rationalizing the affinity changes. The mutations either prevent certain interactions to be formed or allow formation of new interactions – both of afore mentioned have strong effects on the saccharide preferences. Conclusion Mutagenesis of amino acids forming the specificity binding loop allowed

Signalling through C-type lectin receptors: shaping immune responses

NARCIS (Netherlands)

Geijtenbeek, Teunis B. H.; Gringhuis, Sonja I.

2009-01-01

C-type lectin receptors (CLRs) expressed by dendritic cells are crucial for tailoring immune responses to pathogens. Following pathogen binding, CLRs trigger distinct signalling pathways that induce the expression of specific cytokines which determine T cell polarization fates. Some CLRs can induce

Alternate gram staining technique using a fluorescent lectin.

Science.gov (United States)

Sizemore, R K; Caldwell, J J; Kendrick, A S

1990-01-01

Fluorescence-labeled wheat germ agglutinin binds specifically to N-acetylglucosamine in the outer peptidoglycan layer of gram-positive bacteria. The peptidoglycan layer of gram-negative bacteria is covered by a membrane and is not labeled by the lectin. By exploiting this phenomenon, an alternative Gram staining technique has been developed. Images PMID:1697149

Tetranectin, a trimeric plasminogen-binding C-type lectin

DEFF Research Database (Denmark)

Holtet, T L; Graversen, Jonas Heilskov; Clemmensen, I

1997-01-01

-linking analysis and SDS-PAGE to be a homo-trimer in solution as are other known members of the collectin family of C-type lectins. Biochemical evidence is presented showing that an N-terminal domain encoded within exons 1 and 2 of the tetranectin gene is necessary and sufficient to govern subunit trimerization....

Evaluation of glycophenotype in breast cancer by quantum dot-lectin histochemistry

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Andrade CG

2013-12-01

Full Text Available Camila G Andrade,1 Paulo E Cabral Filho,2 Denise PL Tenório,3 Beate S Santos,4 Eduardo IC Beltrão,1 Adriana Fontes,2 Luiz B Carvalho Jr1 1Keizo Asami Immunopathology Laboratory, 2Biophysics and Radiobiology Department, 3Fundamental Chemistry Department, 4Pharmaceutical Science Department, Federal University of Pernambuco, Recife, Pernambuco, Brazil Abstract: Cell surface glycoconjugates play an important role in differentiation/dedifferentiation processes and lectins are employed to evaluate them by several methodologies. Fluorescent probes are considered a valuable tool because of their ability to provide a particular view, and are more detailed and sensitive in terms of cell structure and molecular content. The aim of this study was to evaluate and compare the expression and distribution of glycoconjugates in normal human breast tissue, and benign (fibroadenoma, and malignantly transformed (invasive ductal carcinoma breast tissues. For this, we used mercaptosuccinic acid-coated Cadmium Telluride (CdTe quantum dots (QDs conjugated with concanavalin A (Con A or Ulex europaeus agglutinin I (UEA I lectins to detect α-D-glucose/mannose and L-fucose residues, respectively. The QD-lectin conjugates were evaluated by hemagglutination activity tests and carbohydrate inhibition assays, and were found to remain functional, keeping their fluorescent properties and carbohydrate recognition ability. Fluorescence images showed that different regions of breast tissue expressed particular types of carbohydrates. While the stroma was preferentially and intensely stained by QD-Con A, ductal cells were preferentially labeled by QD-UEA I. These results indicate that QD-lectin conjugates can be used as molecular probes and can help to elucidate the glycoconjugate profile in biological processes. Keywords: nanoparticles, concanavalin A, Ulex europaeus, carbohydrates, mammary tissues

Plant lectin can target receptors containing sialic acid, exemplified by podoplanin, to inhibit transformed cell growth and migration.

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Jhon Alberto Ochoa-Alvarez

Full Text Available Cancer is a leading cause of death of men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority of cancer deaths. Extracellular receptors modified by α2,3-sialic acids that promote this motility can serve as ideal chemotherapeutic targets. For example, the extracellular domain of the mucin receptor podoplanin (PDPN is highly O-glycosylated with α2,3-sialic acid linked to galactose. PDPN is activated by endogenous ligands to induce tumor cell motility and metastasis. Dietary lectins that target proteins containing α2,3-sialic acid inhibit tumor cell growth. However, anti-cancer lectins that have been examined thus far target receptors that have not been identified. We report here that a lectin from the seeds of Maackia amurensis (MASL with affinity for O-linked carbohydrate chains containing sialic acid targets PDPN to inhibit transformed cell growth and motility at nanomolar concentrations. Interestingly, the biological activity of this lectin survives gastrointestinal proteolysis and enters the cardiovascular system to inhibit melanoma cell growth, migration, and tumorigenesis. These studies demonstrate how lectins may be used to help develop dietary agents that target specific receptors to combat malignant cell growth.

An acetylation site in lectin domain modulates the biological activity of polypeptide GalNAc-transferase-2

DEFF Research Database (Denmark)

Zlocowski, Natacha; Lorenz, Virginia; Bennett, Eric Paul

2013-01-01

Abstract Polypeptide GalNAc-transferases (ppGalNAc-Ts) are a family of enzymes that catalyze the initiation of mucin-type O-glycosylation. All ppGalNAc-T family members contain a common (QXW)3 motif which is present in R-type lectin group. Acetylation site K521 is part of the QKW motif of ß......-trefoil in the lectin domain of ppGalNAc-T2. We used a combination of acetylation and site-directed mutagenesis approaches to examine the functional role of K521 in ppGalNAc-T2. Binding assays of non-acetylated and acetylated forms of the mutant ppGalNAc-T2K521Q to various naked and aGalNAc-glycosylated mucin peptides...... indicated that degree of interaction of lectin domain with aGalNAc depends on the peptide sequence of mucin. Studies of inhibitory effect of various carbohydrates on interactions of ppGalNAc-T2 with MUC1aGalNAc indicate that point K521Q mutation enhance the carbohydrate specificity of lectin domain for aGalNAc...

MCL and mincle: C-type lectin receptors that sense damaged self and pathogen associated molecular patterns

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Mark B Richardson

2014-06-01

Full Text Available MCL (macrophage C-type lectin and mincle (macrophage inducible C-type lectin comprise part of an extensive repertoire of pattern recognition receptors with the ability to sense damage associated and pathogen associated molecular patterns. In this review we cover the discovery and molecular characterization of these C-type lectin receptors, and highlight recent advances in the understanding of their roles in orchestrating the response of the immune system to bacterial and fungal infection, and damaged self. We also discuss the identification and structure-activity relationships of activating ligands, particularly trehalose dimycolate (TDM and related mycobacterial glycolipids, which have significant potential in the development of TH1/TH17 vaccination strategies.

Isolation and Molecular Characterization of Two Lectins from Dwarf Elder (Sambucus ebulus L. Blossoms Related to the Sam n1 Allergen

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Tomas Girbes

2013-10-01

Full Text Available Sambucus species contain a number of lectins with and without antiribosomal activity. Here, we show that dwarf elder (Sambucus ebulus L. blossoms express two D-galactose-binding lectins that were isolated and purified by affinity chromatography and gel filtration. These proteins, which we named ebulin blo (A-B toxin and SELblo (B-B lectin—blo from blossoms—were subjected to molecular characterization and analysis by MALDI-TOF mass spectrometry and tryptic peptide fingerprinting. Both lectins share a high degree of amino acid sequence homology with Sambucus lectins related to the Sam n1 allergen. Ebulin blo, but not SELblo, was highly toxic by nasal instillation to mice. Overall, our results suggested that both lectins would belong to an allergen family exemplified by Sam n1 and could trigger allergy responses. Furthermore, they raise a concern about ebulin blo toxicity.

Extrinsic functions of lectin domains in O-N-acetylgalactosamine glycan biosynthesis

DEFF Research Database (Denmark)

Lorenz, Virginia; Ditamo, Yanina; Cejas, Romina B

2016-01-01

during O-GalNAc glycan biosynthesis. The presence of lectin domain T3lec or T4lec during ppGalNAc-T2 and ppGalNAc-T3 catalytic reaction had a clear inhibitory effect on GalNAc-T activity. Interaction of T3lec or T4lec with ppGalNAc-T2 catalytic domain was not mediated by carbohydrate. T3lec, but not T2......Glycan biosynthesis occurs mainly in Golgi. Molecular organization and functional regulation of this process are not well understood. We evaluated the extrinsic effect of lectin domains (β-trefoil fold) of polypeptide GalNAc-transferases (ppGalNAc-Ts) on catalytic activity of glycosyltransferases...

Effect of the lectin of Bauhinia variegata and its recombinant isoform on surgically induced skin wounds in a murine model.

Science.gov (United States)

Neto, Luiz Gonzaga do Nascimento; Pinto, Luciano da Silva; Bastos, Rafaela Mesquita; Evaristo, Francisco Flávio Vasconcelos; Vasconcelos, Mayron Alves de; Carneiro, Victor Alves; Arruda, Francisco Vassiliepe Sousa; Porto, Ana Lúcia Figueiredo; Leal, Rodrigo Bainy; Júnior, Valdemiro Amaro da Silva; Cavada, Benildo Sousa; Teixeira, Edson Holanda

2011-11-07

Lectins are a structurally heterogeneous group of highly specific carbohydrate-binding proteins. Due to their great biotechnological potential, lectins are widely used in biomedical research. The purpose of the present study was to evaluate the healing potential of the lectin of Bauhinia variegata (nBVL) and its recombinant isoform (rBVL-1). Following surgical creation of dorsal skin wounds, seven groups of mice were submitted to topical treatment for 12 days with lectin, D-galactose, BSA and saline. The animals were anesthetized and euthanized on POD 2, 7 and 12 in order to evaluate the healing potential of each treatment. The parameters considered included wound size, contraction rate, epithelialization rate and histopathological findings. Wound closure was fastest in animals treated with rBVL-1 (POD 7). nBVL was more effective than the controls. All skin layers were reconstructed and keratin deposition increased. Our findings indicate that the lectin of Bauhinia variegata possesses pro-healing properties and may be employed in the treatment of acute skin wounds.

Separation and Enrichment of Lectin from Zihua Snap-Bean (Phaseolus vulgaris Seeds by PEG 600–Ammonium Sulfate Aqueous Two-Phase System

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Bin Jiang

2017-09-01

Full Text Available A fast and efficient method based on a polyethylene glycol (PEG 600/(NH42SO4 aqueous two-phase system for extracting lectin from Zihua snap-bean (Phaseolus vulgaris seeds was established. According to a Box–Behnken design (BBD, involving four factors at three levels each subjected to analysis of variance (ANOVA and response surface analysis, the protein recovery and the purification factor of lectin in the top phase were used as the response values of the variance analysis to acquire the multivariate quadratic regression model. SDS–PAGE electrophoresis and the hemagglutination test were used to detect the distribution of lectin in the aqueous two-phase system (ATPS. The obtained data indicated that lectin was preferentially partitioned into the PEG-rich phase, and the ATPS, composed of 15% (NH42SO4 (w/w, 18% PEG 600 (w/w, 0.4 g/5 g NaCl and 1 mL crude extract, showed good selectivity for lectin when the pH value was 7.5. Under the optimal conditions, most of the lectin was assigned to the top phase in the ATPS, and the hemagglutination activity of the purified lectin in the top phase was 3.08 times that of the crude extract. Consequently, the PEG 600/(NH42SO4 aqueous two-phase system was an effective method for separating and enriching lectin directly from the crude extract of Zihua snap-bean seeds.

Synthesis of Rhodamines from Fluoresceins Using Pd-Catalyzed C–N Cross-Coupling

Science.gov (United States)

2011-01-01

A unified, convenient, and efficient strategy for the preparation of rhodamines and N,N′-diacylated rhodamines has been developed. Fluorescein ditriflates were found to undergo palladium-catalyzed C–N cross-coupling with amines, amides, carbamates, and other nitrogen nucleophiles to provide direct access to known and novel rhodamine derivatives, including fluorescent dyes, quenchers, and latent fluorophores. PMID:22091952

Structural basis of carbohydrate recognition by lectin II from Ulex europaeus, a protein with a promiscuous carbohydrate-binding site.

Science.gov (United States)

Loris, R; De Greve, H; Dao-Thi, M H; Messens, J; Imberty, A; Wyns, L

2000-08-25

Protein-carbohydrate interactions are the language of choice for inter- cellular communication. The legume lectins form a large family of homologous proteins that exhibit a wide variety of carbohydrate specificities. The legume lectin family is therefore highly suitable as a model system to study the structural principles of protein-carbohydrate recognition. Until now, structural data are only available for two specificity families: Man/Glc and Gal/GalNAc. No structural data are available for any of the fucose or chitobiose specific lectins. The crystal structure of Ulex europaeus (UEA-II) is the first of a legume lectin belonging to the chitobiose specificity group. The complexes with N-acetylglucosamine, galactose and fucosylgalactose show a promiscuous primary binding site capable of accommodating both N-acetylglucos amine or galactose in the primary binding site. The hydrogen bonding network in these complexes can be considered suboptimal, in agreement with the low affinities of these sugars. In the complexes with chitobiose, lactose and fucosyllactose this suboptimal hydrogen bonding network is compensated by extensive hydrophobic interactions in a Glc/GlcNAc binding subsite. UEA-II thus forms the first example of a legume lectin with a promiscuous binding site and illustrates the importance of hydrophobic interactions in protein-carbohydrate complexes. Together with other known legume lectin crystal structures, it shows how different specificities can be grafted upon a conserved structural framework. Copyright 2000 Academic Press.

Complementary Roles of the Classical and Lectin Complement Pathways in the Defense against Aspergillus fumigatus

DEFF Research Database (Denmark)

Rosbjerg, Anne; Genster, Ninette; Pilely, Katrine

2016-01-01

Aspergillus fumigatus infections are associated with a high mortality rate for immunocompromised patients. The complement system is considered to be important in protection against this fungus, yet the course of activation is unclear. The aim of this study was to unravel the role of the classical......, lectin, and alternative pathways under both immunocompetent and immunocompromised conditions to provide a relevant dual-perspective on the response against A. fumigatus. Conidia (spores) from a clinical isolate of A. fumigatus were combined with various human serum types (including serum deficient...... complement on A. fumigatus, but required classical and/or lectin pathway for initiation. In normal human serum, this initiation came primarily from the classical pathway. However, with a dysfunctional classical pathway (C1q-deficient serum), lectin pathway activated complement and mediated opsonophagocytosis...

Cancer Biomarker Discovery: Lectin-Based Strategies Targeting Glycoproteins

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David Clark

2012-01-01

Full Text Available Biomarker discovery can identify molecular markers in various cancers that can be used for detection, screening, diagnosis, and monitoring of disease progression. Lectin-affinity is a technique that can be used for the enrichment of glycoproteins from a complex sample, facilitating the discovery of novel cancer biomarkers associated with a disease state.

Expression of Pinellia pedatisecta Lectin Gene in Transgenic Wheat Enhances Resistance to Wheat Aphids

OpenAIRE

Xiaoliang Duan; Qiling Hou; Guoyu Liu; Xiaomeng Pang; Zhenli Niu; Xiao Wang; Yufeng Zhang; Baoyun Li; Rongqi Liang

2018-01-01

Wheat aphids are major pests during the seed filling stage of wheat. Plant lectins are toxic to sap-sucking pests such as wheat aphids. In this study, Pinellia pedatisecta agglutinin (ppa), a gene encoding mannose binding lectin, was cloned, and it shared 92.69% nucleotide similarity and 94% amino acid similarity with Pinellia ternata agglutinin (pta). The ppa gene, driven by the constitutive and phloem-specific ribulose bisphosphate carboxylase small subunit gene (rbcs) promoter in pBAC-rbcs...

Morphological Specifications of the Bird Schistosome Cercariae and Surface Carbohydrates as Receptors for Lectins

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I Moebedi

2007-04-01

Full Text Available Background: To determine the morphological specifications of the bird schistosomes cercaria from Lymnaea gedrosiana and to detect the surface carbohydrates as receptors for host lectins in the host-parasite relationship systems such as avian schistosomiasis and human cercarial dermatitis. Methods: One hundred ninety two snails collected from Dezful areas in Khuzestan Province, in the south west of Iran, during 2005-2006 were examined for cercariae using shedding and crushing methods. In addition, surface carbohydrates on the cercariae were detected by lentil (Lens culinaris lectins. Results: From the total number of Lymnaea gedrosiana, which examined for bird schistosomes cercaria, 9(4% snails were found to be infected with furcocercus cercaria of the bird schistosomes (probably Gigantobilharzia sp.. Mannose monosaccharide CH2OH (CHOH4CHO as surface carbohydrate was also detected on the cercariae. Conclusion: Mannose carbohydrate on these cercariae may be used as receptor by lectins.

Identification of structural and secretory lectin-binding glycoproteins of normal and cancerous human prostate.

Science.gov (United States)

Lad, P M; Cooper, J F; Learn, D B; Olson, C V

1984-12-07

We have utilized the technique of lectin-loading of SDS gels with iodinated concanavalin A and wheat germ agglutinin to identify glycoproteins in prostatic and seminal fluids as well as in prostate tissue fractions. The following subunits which bound both lectins were detected: (a) 50, 43 and 38 kDa subunits common to prostatic and seminal fluids, and an additional 55 kDa subunit which predominates only in prostatic fluid; (b) 78, 55, 50 and 43 kDa subunits in prostatic tissue cytosol and (c) 195, 170, 135, 116 and 95 kDa subunits present in the particulate fractions of prostatic tissue. Immunoblotting using specific rabbit antibodies revealed the 50 kDa band to be prostatic acid phosphatase and the 38 kDa band to be prostate-specific antigen. Interestingly, antibodies directed toward prostatic acid phosphatase were found to cross-react with the 43 kDa band. Fractionation on sucrose gradients showed that several of these particulate glycoproteins were associated with a vesicle fraction enriched in adenylate cyclase activity, implying that they are plasma membrane glycoproteins. Comparison of soluble and particulate fractions of normal and cancerous tissue homogenates was made by densitometric scanning of autoradiograms of lectin-loaded gels. Similar relative intensities of lectin-binding were obtained for corresponding proteins in normal and cancerous tissue fractions. Also, immunoblotting showed no differences in prostatic acid phosphatase or prostate-specific antigen between normal and cancerous soluble homogenate fractions. Our results suggest that major lectin-binding proteins are conserved in the transition from normal to cancerous tissue. These results may be useful in developing a multiple-marker profile of metastatic prostate cancer and for the design of imaging agents, such as monoclonal antibodies, to prominent soluble and particulate prostate glycoproteins.

Carbohydrate/glycan-binding specificity of legume lectins in respect to their proposed biological functions

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Márcio Viana Ramos

2000-01-01

Full Text Available The lectins, proteins which specifically recognize carbohydrate moieties, have been extensively studied in many biochemical and structural aspects in order to establish the molecular basis of this non-catalytic event. On the other hand, their clinical and agricultural potentials have been growing fast. Although lectins, mainly those from legume plants, had been investigated for biological properties, studies about the physiological functions of lectins are scarce in literature. Therefore, despite the accumulated data on lectins (as proteins, the role played by these signalizing molecules is poorly discussed. In the light of our accumulated results on legume lectins, specially those obtained from plants belonging to the Diocleinae sub-tribe and available data in literature, we discuss here the main hypothesis of their functions according to their carbohydrate/glycan-binding specificity.As lectinas, proteinas que especificamente reconhecem estruturas que contém carboidratos, têm sido extensivamente estudadas em muitos aspectos bioquímicos e estruturais, objetivando estabelecer as bases moleculares deste evento não-catalítico. Por outro lado, os potenciais clínicos e agriculturais destas proteínas têm crescido rapidamente. Embora as lectinas, principalmente aquelas de legumes tenham sido bastante investigadas em suas propriedades biológicas, estudos sobre as funcões fisiológicas de lectinas são escassos na literatura. Além disto, a despeito da quantidade de dados acumulados sobre lectinas (como proteínas, o papel desempenhado por estas moléculas de sinalização é pobremente discutido. Valendo-se de nossos estudos sobre lectinas de leguminosas, principalmente da sub-tribo Diocleinae, e outros dados presentes na literatura, discutimos aqui, as principais hipóteses de suas funções com base na especificidade por carboidratos e glicanos complexos.

Inactivation and fragmentation of lectin from Bothrops leucurus snake venom by gamma irradiation

Science.gov (United States)

Nunes, E. S.; Souza, M. A. A.; Vaz, A. F. M.; Coelho, L. C. B. B.; Aguiar, J. S.; Silva, T. G.; Guarnieri, M. C.; Melo, A. M. M. A.; Oliva, M. L. V.; Correia, M. T. S.

2012-04-01

Gamma radiation alters the molecular structure of biomolecules and is able to mitigate the action of snake venoms and their isolated toxins. The effect of γ-radiation on the folding of Bothrops lecurus venom lectin was measured by a hemagglutinating assay, intrinsic and bis-ANS fluorescence. Intrinsic and bis-ANS fluorescence analyses indicated that irradiation caused unfolding followed by aggregation of the lectin. Our results suggest that irradiation can lead to significant changes in the protein structure, which may promote the loss of its binding property and toxic action.

Binding properties of a blood group Le(a+) active sialoglycoprotein, purified from human ovarian cyst, with applied lectins.

Science.gov (United States)

Wu, A M; WU, J H; Watkins, W M; Chen, C P; Tsai, M C

1996-06-07

Studies on the structures and binding properties of the glycoproteins, purified from human ovarian cyst fluids, will aid the understanding of the carbohydrate alterations occurring during the biosynthesis of blood group antigens and neoplasm formation. These glycoproteins can also serve as important biological materials to study blood group A, B, H, Le(a), Le(b), Le(x), Le(y), T and Tn determinants, precursor type I and II sequences and cold agglutinin I and i epitopes. In this study, the binding property of a cyst glycoprotein from a human blood group Le(a+) nonsecretor individual, that contains an unusually high amount (18%) of sialic acid (HOC 350) was characterized by quantitative precipitin assay with a panel of lectins exhibiting a broad range of carbohydrate-binding specificities. Native HOC 350 reacted well only with three out of nineteen lectins tested. It precipitated about 80% of Ricinus communis (RCA1), 50% of Triticum vulgaris (WGA) and 37% of Bauhinia purpurea aba (BPA) agglutinins, respectively. However, its asialo product had dramatically enhanced reactivity and reacted well with many I/II (Gal beta1 --> 3/4GcNAc), T(Gal beta1 --> 3GalNAc) and Tn(GaNIAc alphaI --> Ser/Thr) active lectins. It bound best to Jacalin, BPA, and abrin-a and completely precipitated all the lectins added. Asialo-HOC 350 also reacted strongly with Wistaria floribunda, Abrus precatorius agglutinin, ricin and RCA1 and precipitated over 75% of the lectin nitrogen added, and moderately with Arachis hypogaea, Maclura pomifera, WGA, Vicia viosa-B4, Codium fragile tomentosoides and Ulex europaeus-II. But native HOC 350 and its asialo product reacted not at all or poorly with Dolichos biflorus, Helix pomatia, Lotus tetra-gonolobus, Ulex europaeus-I, Lens culinaris lectins and Con A. The lectin-glycoform interactions through bioactive sugars were confirmed by precipitin inhibition assay. Mapping the precipitation profiles of the interactions have led to the conclusion that HOC 350

A label-free fluorescence biosensor for highly sensitive detection of lectin based on carboxymethyl chitosan-quantum dots and gold nanoparticles

International Nuclear Information System (INIS)

Liu, Ziping; Liu, Hua; Wang, Lei; Su, Xingguang

2016-01-01

In this work, we report a novel label-free fluorescence “turn off-on” biosensor for lectin detection. The highly sensitive and selective sensing system is based on the integration of carboxymethyl chitosan (CM-CHIT), CuInS_2 quantum dots (QDs) and Au nanoparticles (NPs). Firstly, CuInS_2 QDs featuring carboxyl groups were directly synthesized via a hydrothermal synthesis method. Then, the carboxyl groups on the CuInS_2 QDs surface were interacted with the amino groups (−NH_2), carboxyl groups (−COOH) and hydroxyl groups (−OH) within CM-CHIT polymeric chains via electrostatic interactions and hydrogen bonding to form CM-CHIT-QDs assemblies. Introduction of Au NPs could quench the fluorescence of CM-CHIT-QDs through electron and energy transfer. In the presence of lectin, lectin could bind exclusively with CM-CHIT-QDs by means of specific multivalent carbohydrate-protein interaction. Thus, the electron and energy transfer process between CM-CHIT-QDs and Au NPs was inhibited, and as a result, the fluorescence of CM-CHIT-QDs was effectively “turned on”. Under the optimum conditions, there was a good linear relationship between the fluorescence intensity ratio I/I_0 (I and I_0 were the fluorescence intensity of CM-CHIT-QDs-Au NPs in the presence and absence of lectin, respectively) and lectin concentration in the range of 0.2–192.5 nmol L"−"1, And the detection limit could be down to 0.08 nmol L"−"1. Furthermore, the proposed biosensor was employed for the determination of lectin in fetal bovine serum samples with satisfactory results. - Graphical abstract: A label-free fluorescence biosensor for highly sensitive detection of lectin based on the integration of carboxymethyl chitosan, CuInS_2 quantum dots and gold nanoparticles. - Highlights: • A label-free near-infrared fluorescence “turn off-on” biosensor for detection of lectin was established. • The highly sensitive biosensor was based on the inner filter effect of Au NPs on CM

A label-free fluorescence biosensor for highly sensitive detection of lectin based on carboxymethyl chitosan-quantum dots and gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Liu, Ziping; Liu, Hua; Wang, Lei; Su, Xingguang, E-mail: suxg@jlu.edu.cn

2016-08-17

In this work, we report a novel label-free fluorescence “turn off-on” biosensor for lectin detection. The highly sensitive and selective sensing system is based on the integration of carboxymethyl chitosan (CM-CHIT), CuInS{sub 2} quantum dots (QDs) and Au nanoparticles (NPs). Firstly, CuInS{sub 2} QDs featuring carboxyl groups were directly synthesized via a hydrothermal synthesis method. Then, the carboxyl groups on the CuInS{sub 2} QDs surface were interacted with the amino groups (−NH{sub 2}), carboxyl groups (−COOH) and hydroxyl groups (−OH) within CM-CHIT polymeric chains via electrostatic interactions and hydrogen bonding to form CM-CHIT-QDs assemblies. Introduction of Au NPs could quench the fluorescence of CM-CHIT-QDs through electron and energy transfer. In the presence of lectin, lectin could bind exclusively with CM-CHIT-QDs by means of specific multivalent carbohydrate-protein interaction. Thus, the electron and energy transfer process between CM-CHIT-QDs and Au NPs was inhibited, and as a result, the fluorescence of CM-CHIT-QDs was effectively “turned on”. Under the optimum conditions, there was a good linear relationship between the fluorescence intensity ratio I/I{sub 0} (I and I{sub 0} were the fluorescence intensity of CM-CHIT-QDs-Au NPs in the presence and absence of lectin, respectively) and lectin concentration in the range of 0.2–192.5 nmol L{sup −1}, And the detection limit could be down to 0.08 nmol L{sup −1}. Furthermore, the proposed biosensor was employed for the determination of lectin in fetal bovine serum samples with satisfactory results. - Graphical abstract: A label-free fluorescence biosensor for highly sensitive detection of lectin based on the integration of carboxymethyl chitosan, CuInS{sub 2} quantum dots and gold nanoparticles. - Highlights: • A label-free near-infrared fluorescence “turn off-on” biosensor for detection of lectin was established. • The highly sensitive biosensor was based on the

Contents of Sulforaphane and Total Isothiocyanates, Antimutagenic Activity, and Inhibition of Clastogenicity in Pulp Juices from Cruciferous Plants

Czech Academy of Sciences Publication Activity Database

Totušek, J.; Tříska, Jan; Lefnerová, D.; Strohalm, J.; Vrchotová, Naděžda; Zendulka, O.; Průchová, J.; Chaloupková, J.; Novotná, P.; Houška, M.

2011-01-01

Roč. 29, č. 5 (2011), s. 548-556 ISSN 1212-1800 R&D Projects: GA MZe QF3287 Institutional research plan: CEZ:AV0Z60870520 Keywords : cruciferous vegetables * juice * antimutagenic effects * sulforaphane * isothiocyanates Subject RIV: GM - Food Processing Impact factor: 0.522, year: 2011

Lectin complement pathway gene profile of the donor and recipient does not influence graft outcome after kidney transplantation.

NARCIS (Netherlands)

Damman, J.; Kok, J.L.; Snieder, H.; Leuvenink, H.G.; Goor, H. van; Hillebrands, J.L.; Dijk, M.C.R.F. van; Hepkema, B.G.; Reznichenko, A.; Born, J. van den; Borst, M.H. de; Bakker, S.J.; Navis, G.J.; Ploeg, R.J.; Seelen, M.A.

2012-01-01

In kidney transplantation, complement activation was found to be induced by donor brain death, renal ischemia-reperfusion injury and allograft rejection. There are three known pathways of complement activation: the classical, lectin and the alternative pathway. The lectin complement pathway can be

Comparison of the interfacial properties of Eugenia uniflora and Triticum vulgaris lectins.

Science.gov (United States)

Andrade, Cesar A S; Oliveira, Maria D L; Santos-Magalhães, Nereide S; Correia, Maria T S; de Melo, Celso P

2009-01-01

We have investigated the interfacial and dielectric properties of EuniSL, a recently purified lectin obtained from seeds of Eugenia uniflora (EuniSL), through surface pressure (Pi) and surface potential (DeltaV) measurements of its floating monolayers at the 2.0lectins are strongly dependent upon the pH of bulk phase, in general terms EuniSL monolayers seem to be more structured than those of WGA. At the pH range investigated, the interfacial electric double layer values (Psi(0)) calculated from the surface potential are negative, both for EuniSL and WGA. While for EuniSL definite breakpoints in an otherwise linear dependence of Psi(0) and zeta-potential as a function of pH were detected at pH 6.5, similar changes were observed for WGA at pH 8.5, a value close to the isoelectric point (pI) of this lectin. We have then used electrical impedance spectroscopy to investigate the dielectric characteristics of aqueous solutions of the two lectins, assuming a simple Debye relaxation model, and determined the pI of EuniSL as 6.5. While it is well known that the pI of a protein dispersed as a Langmuir film can be determined by surface potential measurements, our results confirm the use of impedance spectroscopy as a valuable and convenient technique that allows the identification of the pI of proteins directly dispersed in aqueous solutions.

Lectin histochemistry of goblet cell sugar residues in the gut of the chick embryo and of the newborn.

Science.gov (United States)

Bryk, S G; Sgambati, E; Gheri Bryk, G

1999-04-01

The anlage of duodenum, ileum and colon were removed from chick embryos of day 8-21 of incubation and from 1-day-old chicks. A battery of seven different horseradish peroxidase-conjugated lectins (PNA, SBA, DBA, Con A, WGA, LTA and UEAI) was used to study the carbohydrate residues of the glycoconjugates in the goblet cells of the three parts of the intestine. The main results can be summarized as follows: differences in lectin binding were absent in the proximal and distal parts of the duodenum, ileum and colon. Lectin histochemistry showed differences among the three intestinal segments for the time of appearance of the oligosaccharides in the goblet mucus. In the colonic goblet cells of 1-day-old chicks, LTA and UEAI lectins showed two different types of linkage of alpha-L-fucose. This is the first demonstration of UEAI reactive sites in Gallus domesticus.

Role of aromatic amino acids in carbohydrate binding of plant lectins : Laser photo chemically induced dynamic nuclear polarization study of hevein domain-containing lectins

NARCIS (Netherlands)

Siebert, HC; vonderLieth, CW; Kaptein, R; Beintema, JJ; Dijkstra, K; vanNuland, N; Soedjanaatmadja, UMS; Rice, A; Vliegenthart, JFG; Wright, CS; Gabius, HJ

Carbohydrate recognition by lectins often involves the side chains of tyrosine, tryptophan, and histidine residues. These moieties are able to produce chemically induced dynamic nuclear polarization (CIDNP) signals after laser irradiation in the presence of a suitable radical pair-generating dye.

Determining the safety and suitability of fluorescein dye for characterization of skin ulcerations in cultured Nile tilapia (Oreochromis niloticus and African sharptooth catfish (Clarias gariepinus

Directory of Open Access Journals (Sweden)

Mai D. Ibrahem

2010-10-01

Full Text Available There is a need to identify the presence of lesions in fish skin as soon as they erupt. Fish skin lesions are either macroscopic (can be visualized by the naked eye or microscopic (difficult to detect with the naked eye. Skin wounds resulting in loss of the epithelium (superficial or deep ulcers are serious as they may interfere with osmoregulation and open portals for opportunistic pathogens. Herein, we report on the use of a fluorescein dye for the detection of skin ulcers that cannot be seen by the naked eye. Due to their importance in aquaculture endeavors in Egypt, this study focused on two indigenous species, the Nile tilapia (Oreochromis niloticus and the scale-less African sharptooth catfish (Clarias gariepinus. Fluorescein dye was tested for safety to fish without interfering with microbiological analysis. Parallel to the use of the flourescein dye, the detected ulcers were examined for the presence of bacteria or tissue alterations. Further, we experimentally induced the formation of skin ulcers in O. niloticus physically or by injecting Aeromons hydrophila, and then assessed the utility of fluorescein dye in detecting the induced skin lesions. Results obtained in this study demonstrated that fluorescein dye application is harmless to Nile tilapia at concentrations up to 0.5 mg fluorescein/ml water for up to 15 min. Indeed, a low dose of fluorescein (0.10 mg/ml for 5 min could identify very minute skin abrasions. We highly recommend the use of fluorescein dye for the evaluation of skin health in farmed fish species and the visualization of minute skin abrasions.

A reduced graphene oxide-based fluorescence resonance energy transfer sensor for highly sensitive detection of matrix metalloproteinase 2.

Science.gov (United States)

Xi, Gaina; Wang, Xiaoping; Chen, Tongsheng

2016-01-01

A novel fluorescence nanoprobe (reduced nano-graphene oxide [nrGO]/fluorescein isothiocyanate-labeled peptide [Pep-FITC]) for ultrasensitive detection of matrix metalloproteinase 2 (MMP2) has been developed by engineering the Pep-FITC comprising the specific MMP2 substrate domain (PLGVR) onto the surface of nrGO particles through non-covalent linkage. The nrGO was obtained by water bathing nano-graphene oxide under 90°C for 4 hours. After mixing the nrGO and Pep-FITC for 30 seconds, the fluorescence from Pep-FITC was almost completely quenched due to the fluorescence resonance energy transfer between fluorescein isothiocyanate (FITC) and nrGO. Upon cleavage of the amide bond between Leu and Gly in the Pep-FITC by protease-MMP2, the FITC bound to nrGO was separated from nrGO surface, disrupting the fluorescence resonance energy transfer process and resulting in fluorescence recovery of FITC. Under optimal conditions, the fluorescence recovery of nrGO/Pep-FITC was found to be directly proportional to the concentration of MMP2 within 0.02-0.1 nM. The detection limit of the nrGO/Pep-FITC was determined to be 3 pM, which is approximately tenfold lower than that of the unreduced carboxylated nano-graphene oxide/Pep-FITC probe.

Novel Fluorometric Method for the Determination of Production Rate and Steady-State Concentration of Photochemically Generated Superoxide Radical in Seawater Using 3',6'-(Diphenylphosphinyl)fluorescein.

Science.gov (United States)

Anifowose, Adebanjo Jacob; Takeda, Kazuhiko; Sakugawa, Hiroshi

2015-12-15

Superoxide radical (O2(•-)) is an important reactive oxygen species in seawater. Measurements of its production rates and steady-state concentrations generated by photochemical processes have been a Herculean task over the years. In this study, a probe - 3'6'-(diphenylphosphinyl)fluorescein (PF-1) - was used to trap photochemically generated O2(•-) in seawater, thereby yielding fluorescein. The fluorescein produced was measured by an isocratic fluorescence HPLC at excitation/emission wavelengths of 490/513 nm, respectively. The reaction rate constant of PF-1 with O2(•-) (kPF-1) was pH-dependent: (3.2-23.5) × 10(7) M(-1) s(-1) at pHTOT 7.65-8.50. By applying appropriate equations, both the production rate and the steady-state concentration of O2(•-) generated by photochemical reactions in the seawater were quantified. Under the optimized experimental conditions, fluorescein standards (3-50 nM) exhibited linearity in the seawater by HPLC. The photoformation of fluorescein, due to the reaction of PF-1 with the O2(•-) photochemically produced in the seawater, was linear within the 20 min irradiation. The detection limit of the fluorescein photoformation rate was 0.03 pM s(-1), defined as 3σ of the lowest standard fluorescein concentration per 20 min irradiation. Using this value, the yield of fluorescein, and the fraction of O2(•-) that reacted with PF-1 in the seawater, the detection limit of the O2(•-) photoformation rate was 1.78 pM s(-1). Superoxide measurements using the proposed method were relatively unaffected by the potential interfering species in seawater. Application of the proposed method to ten (10) seawater samples from the Seto Inland Sea, Japan, resulted in measured O2(•-) photoformation rates of 3.1-8.5 nM s(-1), with steady-state concentrations ranging (0.06-0.3) × 10(-10) M. The method is simple, requires no technical sample preparation, and can be used to analyze a large number of samples.

Distribution of Glycan Motifs at the Surface of Midgut Cells in the Cotton Leafworm (Spodoptera littoralis Demonstrated by Lectin Binding

Directory of Open Access Journals (Sweden)

Tomasz Walski

2017-12-01

Full Text Available Glycans are involved in many biological phenomena, including signal transduction, cell adhesion, immune response or differentiation. Although a few papers have reported on the role of glycans in the development and proper functioning of the insect midgut, no data are available regarding the localization of the glycan structures on the surface of the cells in the gut of insects. In this paper, we analyzed the spatial distribution of glycans present on the surface of the midgut cells in larvae of the cotton leafworm Spodoptera littoralis, an important agricultural pest insect worldwide. For this purpose, we established primary midgut cell cultures, probed these individual cells that are freely suspended in liquid medium with a selection of seven fluorescently labeled lectins covering a range of different carbohydrate binding specificities [mannose oligomers (GNA and HHA, GalNAc/Gal (RSA and SSA, GlcNAc (WGA and Nictaba and Neu5Ac(α-2,6Gal/GalNAc (SNA-I], and visualized the interaction of these lectins with the different zones of the midgut cells using confocal microscopy. Our analysis focused on the typical differentiated columnar cells with a microvillar brush border at their apical side, which are dominantly present in the Lepidopteran midgut and function in food digestion and absorption, and as well as on the undifferentiated stem cells that are important for midgut development and repair. Confocal microscopy analyses showed that the GalNAc/Gal-binding lectins SSA and RSA and the terminal GlcNAc-recognizing WGA bound preferentially to the apical microvillar zone of the differentiated columnar cells as compared to the basolateral pole. The reverse result was observed for the mannose-binding lectins GNA and HHA, as well as Nictaba that binds preferentially to GlcNAc oligomers. Furthermore, differences in lectin binding to the basal and lateral zones of the cell membranes of the columnar cells were apparent. In the midgut stem cells, GNA and

Natural isothiocyanates express antimicrobial activity against developing and mature biofilms of Pseudomonas aeruginosa.

Science.gov (United States)

Kaiser, Stefan J; Mutters, Nico T; Blessing, Brigitte; Günther, Frank

2017-06-01

The antimicrobial properties of natural isothiocyanates (ITCs) found in plants such as nasturtium (Tropaeolum majus) and horseradish (Armoracia rusticana), and the need of new chemotherapeutic options for treatment of infections caused by multidrug-resistant and biofilm-forming Gram-negative bacteria such as Pseudomonas aeruginosa (Pa), led us to evaluate the effects of three major ITCs, allylisothiocyanate (AITC), benzylisothiocyanate (BITC), and phenylethyl-isothiocyanate (PEITC), and a mixture (ITCM) adapted to the ITC composition after release of active components out of natural sources. Out of 105Pa isolates 27 isolates with increased biofilm formation were selected for testing. The effects of ITCs on Pa were evaluated regarding (1) planktonic bacterial proliferation, (2) biofilm formation, (3) metabolic activity in mature biofilms, and (4) synergism of ITCs and antibiotics. (1) Each ITC had anti-Pa activity. Mean minimum inhibitory concentrations (MICs) were (μg/ml, mean±standard deviation): AITC 103±6.9; BITC, 2145±249; PEITC 29,423±1652; and ITCM, 140±5. (2) Treating bacteria with PEITC and ITCM in concentrations below the MIC significantly inhibited biofilm formation. Particularly, ITCM reduced biofilm mass and bacterial proliferation. (3) ITCs significantly inhibited metabolic activity in mature biofilms. (4) Combining ITCs with meropenem synergistically increased antimicrobial efficacy on Pa biofilms. ITCs represent a promising group of natural anti-infective compounds with activity against Pa biofilms. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Quantitation and histochemical localization of galectin-1 and galectin-1-reactive glycoconjugates in fetal development of bovine organs.

Science.gov (United States)

Kaltner, H; Lips, K S; Reuter, G; Lippert, S; Sinowatz, F; Gabius, H J

1997-10-01

, kidney and liver demonstrate that the localization of the galectin and of lectin-reactive epitopes can show a similar distribution, as seen in liver and heart, with organ-typical quantitative changes of a rather similar staining profile (heart, kidney) or notable changes in the spatial distribution (liver) in the course of development. This report emphasizes the potential value of combined monitoring of the lectin and its potential in vivo ligands to contribute to eventually unravel organ-related function(s) of a tissue lectin.

Development of gastrointestinal surface. VIII. Lectin identification of carbohydrate differences

International Nuclear Information System (INIS)

Pang, K.Y.; Bresson, J.L.; Walker, W.A.

1987-01-01

Binding of microvillus membranes (MVM) from newborn and adult rats by concanavalin A (Con A), Ulex europaeus (UEA I), Dolichos bifluorus (DBA), and Triticum vulgaris (WGA) was examined to determine the availability of carbohydrate-containing sites for these lectins on the intestinal surface during development. Consistent patterns of differences in the reaction of MVM with these lectins were found. Con A and UEA had much higher reactivities to MVM of adult than newborn rats. 125 I-labeled-UEA gel overlay experiments revealed the abundance of UEA-binding sites in MVM of adult rat in contrast to the two binding sites in MVM of a newborn rat. DBA bound only to MVM of the adults, and very few binding sites were found in immature MVM. In contrast to these lectins, WGA binding was much higher in MVM of the newborns and decreased with maturation. Additional experiments on the age dependence of UEA and DBA reactivities revealed that the most striking changes occur in animals from 2 to 2 wk of age. In MVM from 2-wk-old rats, there were only 13.9% and < 0.2% of the adult binding capacities for UEA and DBA, respectively. By the time the animals were 4 wk old, the binding capacity for UEA had attained close to the level of the adults, whereas for DBA it reached 71.3% of the adult value. These results provide definite evidence of changes in the intestinal surface during perinatal development

Development of gastrointestinal surface. VIII. Lectin identification of carbohydrate differences

Energy Technology Data Exchange (ETDEWEB)

Pang, K.Y.; Bresson, J.L.; Walker, W.A.

1987-05-01

Binding of microvillus membranes (MVM) from newborn and adult rats by concanavalin A (Con A), Ulex europaeus (UEA I), Dolichos bifluorus (DBA), and Triticum vulgaris (WGA) was examined to determine the availability of carbohydrate-containing sites for these lectins on the intestinal surface during development. Consistent patterns of differences in the reaction of MVM with these lectins were found. Con A and UEA had much higher reactivities to MVM of adult than newborn rats. /sup 125/I-labeled-UEA gel overlay experiments revealed the abundance of UEA-binding sites in MVM of adult rat in contrast to the two binding sites in MVM of a newborn rat. DBA bound only to MVM of the adults, and very few binding sites were found in immature MVM. In contrast to these lectins, WGA binding was much higher in MVM of the newborns and decreased with maturation. Additional experiments on the age dependence of UEA and DBA reactivities revealed that the most striking changes occur in animals from 2 to 2 wk of age. In MVM from 2-wk-old rats, there were only 13.9% and < 0.2% of the adult binding capacities for UEA and DBA, respectively. By the time the animals were 4 wk old, the binding capacity for UEA had attained close to the level of the adults, whereas for DBA it reached 71.3% of the adult value. These results provide definite evidence of changes in the intestinal surface during perinatal development.

Step-By-Step In Vitro Mutagenesis: Lessons From Fucose-Binding Lectin PA-IIL.

Science.gov (United States)

Mrázková, Jana; Malinovská, Lenka; Wimmerová, Michaela

2017-01-01

Site-directed mutagenesis is a powerful technique which is used to understand the basis of interactions between proteins and their binding partners, as well as to modify these interactions. Methods of rational design that are based on detailed knowledge of the structure of a protein of interest are often used for preliminary investigations of the possible outcomes which can result from the practical application of site-directed mutagenesis. Also, random mutagenesis can be used in tandem with site-directed mutagenesis for an examination of amino acid "hotspots."Lectins are sugar-binding proteins which, among other functions, mediate the recognition of host cells by a pathogen and its adhesion to the host cell surface. Hence, lectins and their binding properties are studied and engineered using site-directed mutagenesis.In this chapter, we describe a site-directed mutagenesis method used for investigating the sugar binding pattern of the PA-IIL lectin from the pathogenic bacterium Pseudomonas aeruginosa. Moreover, procedures for the production and purification of PA-IIL mutants are described, and several basic methods for characterizing the mutants are discussed.

Capture of cell culture-derived influenza virus by lectins: strain independent, but host cell dependent.

Science.gov (United States)

Opitz, Lars; Zimmermann, Anke; Lehmann, Sylvia; Genzel, Yvonne; Lübben, Holger; Reichl, Udo; Wolff, Michael W

2008-12-01

Strategies to control influenza outbreaks are focused mainly on prophylactic vaccination. Human influenza vaccines are trivalent blends of different virus subtypes. Therefore and due to frequent antigenic drifts, strain independent manufacturing processes are required for vaccine production. This study verifies the strain independency of a capture method based on Euonymus europaeus lectin-affinity chromatography (EEL-AC) for downstream processing of influenza viruses under various culture conditions propagated in MDCK cells. A comprehensive lectin binding screening was conducted for two influenza virus types from the season 2007/2008 (A/Wisconsin/67/2005, B/Malaysia/2506/2004) including a comparison of virus-lectin interaction by surface plasmon resonance technology. EEL-AC resulted in a reproducible high product recovery rate and a high degree of contaminant removal in the case of both MDCK cell-derived influenza virus types demonstrating clearly the general applicability of EEL-AC. In addition, host cell dependency of EEL-AC was studied with two industrial relevant cell lines: Vero and MDCK cells. However, the choice of the host cell lines is known to lead to different product glycosylation profiles. Hence, altered lectin specificities have been observed between the two cell lines, requiring process adaptations between different influenza vaccine production systems.

Dynamic interplay between catalytic and lectin domains of GalNAc-transferases modulates protein O-glycosylation

DEFF Research Database (Denmark)

Lira-Navarrete, Erandi; de Las Rivas, Matilde; Compañón, Ismael

2015-01-01

the first crystal structures of complexes of GalNAc-T2 with glycopeptides that together with enhanced sampling molecular dynamics simulations demonstrate a cooperative mechanism by which the lectin domain enables free acceptor sites binding of glycopeptides into the catalytic domain. Atomic force microscopy......Protein O-glycosylation is controlled by polypeptide GalNAc-transferases (GalNAc-Ts) that uniquely feature both a catalytic and lectin domain. The underlying molecular basis of how the lectin domains of GalNAc-Ts contribute to glycopeptide specificity and catalysis remains unclear. Here we present...... and small-angle X-ray scattering experiments further reveal a dynamic conformational landscape of GalNAc-T2 and a prominent role of compact structures that are both required for efficient catalysis. Our model indicates that the activity profile of GalNAc-T2 is dictated by conformational heterogeneity...

[Studies on the location of eight lectins in breast carcinoma].

Science.gov (United States)

Zheng, Z; Ji, Z M

1990-12-01

100 cases of breast carcinoma were studied with lectin affinitive histochemistry technology. The result showed that Ricinus comunis agglutinin (RCA1) was located in almost all intraductal carcinomas but one, while the positive rates in the other types were obviously low (P less than 0.05). The positive rate of Ulex europaeus agglutinin-I (UEA1) in well-differentiated types was higher than that in poorly-differentiated ones (P less than 0.05). The location of Peanut agglutinin (PNA), Bandeiraea Simplicifolia (BSL) and UEA1 in breast carcinomas exhibited some regularity and it might be useful in understanding the differentiation of breast carcinomas. No relationship between changes of the eight lectins and metastases in axillary lymph nodes was observed, but the authors considered that PNA-affinitive histochemistry was beneficial to the detection of micrometastases in lymph nodes.

Complement-mediated neutralization of dengue virus requires mannose-binding lectin

DEFF Research Database (Denmark)

Avirutnan, Panisadee; Hauhart, Richard E; Marovich, Mary A

2011-01-01

-dependent activation of the complement cascade neutralized insect cell-derived West Nile virus (WNV) in cell culture and restricted pathogenesis in mice. Here, we investigated the antiviral activity of MBL in infection by dengue virus (DENV), a related flavivirus. Using a panel of naïve sera from mouse strains...... with lower levels. Our studies suggest that allelic variation of MBL in humans may impact complement-dependent control of DENV pathogenesis. IMPORTANCE Dengue virus (DENV) is a mosquito-transmitted virus that causes a spectrum of clinical disease in humans ranging from subclinical infection to dengue...... hemorrhagic fever and dengue shock syndrome. Four serotypes of DENV exist, and severe illness is usually associated with secondary infection by a different serotype. Here, we show that mannose-binding lectin (MBL), a pattern recognition molecule that initiates the lectin pathway of complement activation...

Composition of extracts of airborne grain dusts: lectins and lymphocyte mitogens.

Science.gov (United States)

Olenchock, S A; Lewis, D M; Mull, J C

1986-01-01

Airborne grain dusts are heterogeneous materials that can elicit acute and chronic respiratory pathophysiology in exposed workers. Previous characterizations of the dusts include the identification of viable microbial contaminants, mycotoxins, and endotoxins. We provide information on the lectin-like activity of grain dust extracts and its possible biological relationship. Hemagglutination of erythrocytes and immunochemical modulation by antibody to specific lectins showed the presence of these substances in extracts of airborne dusts from barley, corn, and rye. Proliferation of normal rat splenic lymphocytes in vitro provided evidence for direct biological effects on the cells of the immune system. These data expand the knowledge of the composition of grain dusts (extracts), and suggest possible mechanisms that may contribute to respiratory disease in grain workers. PMID:3709474

Sugar residues content and distribution in atrophic and hyperplastic postmenopausal human endometrium: lectin histochemistry.

Science.gov (United States)

Gheri, G; Bryk, S G; Taddei, G; Moncini, D; Noci, I

1996-10-01

A lectin histochemical study was performed to investigate the glycoconjugate saccharidic moieties of the human postmenopausal endometrium (14 atrophic and 15 hyperplastic). For this purpose a battery of seven horseradish peroxidase-conjugated lectins (PNA, SBA, DBA, WGA, ConA, LTA and UEA I) was used. No differences in lectin binding between atrophic and hyperplastic endometria were observed. This investigation allowed us to provide a basic picture of the oligosaccharidic distribution in postmenopausal endometria. The data on the saccharidic distribution at the postmenopausal endometria showed a large amount of sugar residues at all the investigated sites, i.e. the lining and glandular epithelium, the stroma and the vessels (capillary and large vessels). Furthermore, at the endometrial lining epithelium, at the glands and at the wall of the blood vessels of some postmenopausal women the presence of alpha-L-fucosyl residues which bind via alpha (1-6) linkage to penultimate glucosaminyl residues and/or difucosylated oligosaccharides was demonstrated for the first time.

Effects of indian coral tree, Erythrina indica lectin on eggs and larval development of melon fruit fly, Bactrocera cucurbitae.

Science.gov (United States)

Singh, Kuljinder; Kaur, Manpreet; Rup, Pushpinder J; Singh, Jatinder

2009-07-01

Present study was undertaken to investigate the influence of D-galactose binding lectin from Erythrina indica Lam. on the eggs and second instar larvae (64-72 hr) of melon fruit fly, Bactrocera cucurbitae (Coquillett). The lectin from E. indica seeds was extracted and purified by affinity chromatography using asilofetuin linked porous amino activated silica beads. The effects of various concentrations (0, 125, 250, 500 and 1000 microg ml(-1)) of lectin were studied on freshly laid eggs (0-8 hr) of B. cucurbitae which showed non-significant reduction in percent hatching of eggs. However, the treatment of second instar larvae (64-72 hr) with various test concentrations (0, 25, 50, 100 and 200 microg ml(-1)) of lectin significantly reduced the percent pupation and percent emergence of B. cucurbitae depicting a negative correlation with the lectin concentration. The LC50 (81 microg ml(-1)) treatment significantly decreased the pupal weight. Moreover, the treatment of larvae had also induced a significant increase in the remaining development duration. The activity of three hydrolase enzymes (esterases, acid and alkaline phosphatases), one oxidoreductase (catalase) and one group transfer enzyme (glutathione S-transferases) was assayed in second instar larvae under the influence of LC50 concentration of lectin for three exposure intervals (24, 48 and 72 hr). It significantly suppressed the activity of all the enzymes after all the three exposure intervals except for esterases which increased significantly.

Benzyl isothiocyanate, a major component from the roots of Salvadora persica is highly active against Gram-negative bacteria.

Directory of Open Access Journals (Sweden)

Abier Sofrata

Full Text Available Plants produce a number of antimicrobial substances and the roots of the shrub Salvadora persica have been demonstrated to possess antimicrobial activity. Sticks from the roots of S. persica, Miswak sticks, have been used for centuries as a traditional method of cleaning teeth. Diverging reports on the chemical nature and antimicrobial repertoire of the chewing sticks from S. persica led us to explore its antibacterial properties against a panel of pathogenic or commensal bacteria and to identify the antibacterial component/s by methodical chemical characterization. S. persica root essential oil was prepared by steam distillation and solid-phase microextraction was used to sample volatiles released from fresh root. The active compound was identified by gas chromatography-mass spectrometry and antibacterial assays. The antibacterial compound was isolated using medium-pressure liquid chromatography. Transmission electron microscopy was used to visualize the effect on bacterial cells. The main antibacterial component of both S. persica root extracts and volatiles was benzyl isothiocyanate. Root extracts as well as commercial synthetic benzyl isothiocyanate exhibited rapid and strong bactericidal effect against oral pathogens involved in periodontal disease as well as against other Gram-negative bacteria, while Gram-positive bacteria mainly displayed growth inhibition or remained unaffected. The short exposure needed to obtain bactericidal effect implies that the chewing sticks and the essential oil may have a specific role in treatment of periodontal disease in reducing Gram-negative periodontal pathogens. Our results indicate the need for further investigation into the mechanism of the specific killing of Gram-negative bacteria by S. persica root stick extracts and its active component benzyl isothiocyanate.

Cereal n-glycoproteins enrichment by lectin affinity monolithic chromatography

Czech Academy of Sciences Publication Activity Database

Flodrová, Dana; Bobálová, Janette; Laštovičková, Markéta

2016-01-01

Roč. 44, č. 2 (2016), s. 286-297 ISSN 0133-3720 R&D Projects: GA ČR(CZ) GPP503/12/P395 Institutional support: RVO:68081715 Keywords : barley * wheat * glycoprotein * mass spectrometry * lectin chromatography Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.496, year: 2016

Fungal lectin MpL enables entry of protein drugs into cancer cells and their subcellular targeting.

Science.gov (United States)

Å Urga, Simon; Nanut, Milica Perišić; Kos, Janko; Sabotič, Jerica

2017-04-18

Lectins have been recognized as promising carrier molecules for targeted drug delivery. They specifically bind carbohydrate moieties on cell membranes and trigger cell internalization. Fungal lectin MpL (Macrolepiota procera lectin) does not provoke cancer cell cytotoxicity but is able to bind aminopeptidase N (CD13) and integrin α3β1, two glycoproteins that are overexpressed on the membrane of tumor cells. Upon binding, MpL is endocytosed in a clathrin-dependent manner and accumulates initially in the Golgi apparatus and, finally, in the lysosomes. For effective binding and internalization a functional binding site on the α-repeat is needed. To test the potential of MpL as a carrier for delivering protein drugs to cancer cells we constructed fusion proteins consisting of MpL and the cysteine peptidase inhibitors cystatin C and clitocypin. The fused proteins followed the same endocytic route as the unlinked MpL. Peptidase inhibitor-MpL fusions impaired both the intracellular degradation of extracellular matrix and the invasiveness of cancer cells. MpL is thus shown in vitro to be a lectin that can enable protein drugs to enter cancer cells, enhance their internalization and sort them to lysosomes and the Golgi apparatus.

Effect of the Lectin of Bauhinia variegata and Its Recombinant Isoform on Surgically Induced Skin Wounds in a Murine Model

Directory of Open Access Journals (Sweden)

Rodrigo Bainy Leal

2011-11-01

Full Text Available Lectins are a structurally heterogeneous group of highly specific carbohydrate-binding proteins. Due to their great biotechnological potential, lectins are widely used in biomedical research. The purpose of the present study was to evaluate the healing potential of the lectin of Bauhinia variegata (nBVL and its recombinant isoform (rBVL-1. Following surgical creation of dorsal skin wounds, seven groups of mice were submitted to topical treatment for 12 days with lectin, D-galactose, BSA and saline. The animals were anesthetized and euthanized on POD 2, 7 and 12 in order to evaluate the healing potential of each treatment. The parameters considered included wound size, contraction rate, epithelialization rate and histopathological findings. Wound closure was fastest in animals treated with rBVL-1 (POD 7. nBVL was more effective than the controls. All skin layers were reconstructed and keratin deposition increased. Our findings indicate that the lectin of Bauhinia variegata possesses pro-healing properties and may be employed in the treatment of acute skin wounds.

Two Chitotriose-Specific Lectins Show Anti-Angiogenesis, Induces Caspase-9-Mediated Apoptosis and Early Arrest of Pancreatic Tumor Cell Cycle.

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Ruby Singh

Full Text Available The antiproliferative activity of two chito-specific agglutinins purified from Benincasa hispida (BhL and Datura innoxia (DiL9 of different plant family origin was investigated on various cancer cell lines. Both lectins showed chitotriose specificity, by inhibiting lectin hemagglutinating activity. On further studies, it was revealed that these agglutinins caused remarkable concentration-dependent antiproliferative effect on human pancreatic cancerous cells but not on the normal human umbilical vein endothelial cells even at higher doses determined using MTT assay. The GI50 values were approximately 8.4 μg ml(-1 (0.247 μM and 142 μg ml(-1 (14.8 μM for BhL and DiL9, respectively, against PANC-1 cells. The growth inhibitory effect of these lectins on pancreatic cancer cells were shown to be a consequence of lectin cell surface binding and triggering G0/G1 arrest, mitochondrial membrane depolarization, sustained increase of the intracellular calcium release and the apoptotic signal is amplified by activation of caspases executing cell death. Interestingly, these lectins also showed anti-angiogenic activity by disrupting the endothelial tubulogenesis. Therefore, we report for the first time two chito-specific lectins specifically binding to tumor glycans; they can be considered to be a class of molecules with antitumor activity against pancreatic cancer cells mediated through caspase dependent mitochondrial apoptotic pathway.

Neurogenic plasma exudation mediates grain dust-induced tissue injury in vivo.

Science.gov (United States)

Gao, X P; Von Essen, S; Rubinstein, I

1997-02-01

The purpose of this study was to determine whether an aqueous extract of grain sorghum dust (GDE) elicits neurogenic plasma exudation in the oral mucosa in vivo. Using intravital microscopy, we found that GDE elicited significant, concentration-dependent leaky site formation and an increase in clearance of fluorescein isothiocyanate-labeled dextran (FITC-dextran; mol mass 70 kDa) from the hamster cheek pouch (P grain sorghum dust elicits immediate oral mucosa inflammation in vivo.

Structural analysis and unique molecular recognition properties of a Bauhinia forficata lectin that inhibits cancer cell growth.

Science.gov (United States)

Lubkowski, Jacek; Durbin, Sarah V; Silva, Mariana C C; Farnsworth, David; Gildersleeve, Jeffrey C; Oliva, Maria Luiza V; Wlodawer, Alexander

2017-02-01

Lectins have been used at length for basic research and clinical applications. New insights into the molecular recognition properties enhance our basic understanding of carbohydrate-protein interactions and aid in the design/development of new lectins. In this study, we used a combination of cell-based assays, glycan microarrays, and X-ray crystallography to evaluate the structure and function of the recombinant Bauhinia forficata lectin (BfL). The lectin was shown to be cytostatic for several cancer cell lines included in the NCI-60 panel; in particular, it inhibited growth of melanoma cancer cells (LOX IMVI) by over 95%. BfL is dimeric in solution and highly specific for binding of oligosaccharides and glycopeptides with terminal N-acetylgalactosamine (GalNAc). BfL was found to have especially strong binding (apparent K d  = 0.5-1.0 nm) to the tumor-associated Tn antigen. High-resolution crystal structures were determined for the ligand-free lectin, as well as for its complexes with three Tn glycopeptides, globotetraose, and the blood group A antigen. Extensive analysis of the eight crystal structures and comparison to structures of related lectins revealed several unique features of GalNAc recognition. Of special note, the carboxylate group of Glu126, lining the glycan-binding pocket, forms H-bonds with both the N-acetyl of GalNAc and the peptide amido group of Tn antigens. Stabilization provided by Glu126 is described here for the first time for any GalNAc-specific lectin. Taken together, the results provide new insights into the molecular recognition of carbohydrates and provide a structural understanding that will enable rational engineering of BfL for a variety of applications. Structural data are available in the PDB under the accession numbers 5T50, 5T52, 5T55, 5T54, 5T5L, 5T5J, 5T5P, and 5T5O. © 2016 Federation of European Biochemical Societies.

Incident microalbuminuria and complement factor mannan-binding lectin-associated protein 19 in people with newly diagnosed type 1 diabetes

DEFF Research Database (Denmark)

Ostergaard, J A; Thiel, S; Hoffmann-Petersen, I T

2017-01-01

BACKGROUND: Evidence links the lectin pathway of complement activation to diabetic kidney disease. Upon carbohydrate-recognition by pattern-recognition molecules, e.g., mannan-binding lectin (MBL), the MBL-associated serine protease (MASP-2) is activated and initiates the complement cascade. The ...

Mitogenic Properties Of Lectin From Mucuna Sloanei Seed Extracts ...

African Journals Online (AJOL)

(p<0.05) increases in the values of the immunological parameters relative to those seen in the controls. This study, suggest that the isolated lectin from mucona sloanei seeds possesses mitogenic properties, and may be useful in the diagnosis and treatment of certain diseases such as blood typing disorders and obesity.

Bias in the absorption coefficient determination of a fluorescent dye, standard reference material 1932 fluorescein solution

International Nuclear Information System (INIS)

DeRose, Paul C.; Kramer, Gary W.

2005-01-01

The absorption coefficient of standard reference material[registered] (SRM[registered]) 1932, fluorescein in a borate buffer solution (pH=9.5) has been determined at λ=488.0, 490.0, 490.5 and 491.0 nm using the US national reference UV/visible spectrophotometer. The purity of the fluorescein was determined to be 97.6% as part of the certification of SRM 1932. The solution measured was prepared gravimetrically by diluting SRM 1932 with additional borate buffer. The value of the absorption coefficient was corrected for bias due to fluorescence that reaches the detector and for dye purity. Bias due to fluorescence was found to be on the order of -1% for both monochromatic and polychromatic (e.g., diode-array based) spectrophotometers

Comparative study of anti-angiogenic activities of luteolin, lectin and lupeol biomolecules.

Science.gov (United States)

Ambasta, Rashmi K; Jha, Saurabh Kumar; Kumar, Dhiraj; Sharma, Renu; Jha, Niraj Kumar; Kumar, Pravir

2015-09-18

Angiogenesis is a hallmark feature in the initiation, progression and growth of tumour. There are various factors for promotion of angiogenesis on one hand and on the other hand, biomolecules have been reported to inhibit cancer through anti-angiogenesis mechanism. Biomolecules, for instance, luteolin, lectin and lupeol are known to suppress cancer. This study aims to compare and evaluate the biomolecule(s) like luteolin, lupeol and lectin on CAM assay and HT-29 cell culture to understand the efficacy of these drugs. The biomolecules have been administered on CAM assay, HT-29 cell culture, cell migration assay. Furthermore, bioinformatics analysis of the identified targets of these biomolecules have been performed. Luteolin has been found to be better in inhibiting angiogenesis on CAM assay in comparison to lupeol and lectin. In line with this study when biomolecules was administered on cell migration assay via scratch assay method. We provided evidence that Luteolin was again found to be better in inhibiting HT-29 cell migration. In order to identify the target sites of luteolin for inhibition, we used software analysis for identifying the best molecular targets of luteolin. Using software analysis best target protein molecule of these biomolecules have been identified. VEGF was found to be one of the target of luteolin. Studies have found several critical point mutation in VEGF A, B and C. Hence docking analysis of all biomolecules with VEGFR have been performed. Multiple allignment result have shown that the receptors are conserved at the docking site. Therefore, it can be concluded that luteolin is not only comparatively better in inhibiting blood vessel in CAM assay, HT-29 cell proliferation and cell migration assay rather the domain of VEGFR is conserved to be targeted by luteolin, lupeol and lectin.

Characterization of the yam tuber storage proteins from Dioscorea batatas exhibiting unique lectin activities.

Science.gov (United States)

Gaidamashvili, Mariam; Ohizumi, Yuki; Iijima, Shinichiro; Takayama, Tomo; Ogawa, Tomohisa; Muramoto, Koji

2004-06-18

Four major proteins designated DB1, DB2, DB3, and DB4 were isolated and characterized from the yam tuber Dioscorea batatas. The ratios of their yields were 20:50:20:10. DB1 was a mannose-binding lectin (20 kDa) consisting of 10-kDa subunits and was classified as the monocot mannose-binding lectin family. DB2, accounting for 50% of the total protein, was the storage protein, commonly called dioscorins consisting of a 31-kDa subunit. On the basis of amino acid sequence, DB2 was classified to be dioscorin A. DB3 was a maltose-binding lectin, having an apparent molecular mass of 120 kDa and composed of a 66-kDa subunit and two 31-kDa subunits (DB3S). The 66-kDa subunit was further composed of two 31-kDa subunits (DB3L) cross-linked by disulfide bonds. DB3L and DB3S (242 and 241 amino acid residues, respectively) were homologous with each other with 72% sequence identity. They showed a sequence homology to dioscorin B and dioscorin A from Dioscorea alata, with 90 and 93% identity, respectively, and to carbonic anhydrase from Arabidopsis thaliana with about 45% identity. DB3S had one intrachain disulfide bond located at Cys(28)-Cys(187), whereas DB3L had one interchain disulfide bond (Cys(40)-Cys(40)') in addition to the intrachain disulfide bond (Cys(28)-Cys(188)) to form a 66-kDa subunit. DB1 and DB3 agglutinated rabbit erythrocytes at 2.7 and 3.9 microg/ml, respectively. Despite the structural homology between DB2 and DB3, DB2 had no lectin activity. The 66-kDa subunit itself revealed the full hemagglutinating activity of DB3, indicating that DB3L but not DB3S was responsible for the activity. The hemagglutinating activity of DB3 required Ca(2+) ions and was exclusively inhibited by maltose and oligomaltoses (e.g. maltopentaose and maltohexaose) but not by d-glucose. DB3 could not be classified into any known plant lectin family. DB4 was a chitinase, homologous to an acidic chitinase from Dioscorea japonica. DB1, DB2, and DB3 did not show any activity of carbonic

Changes in cell surface structure by viral transformation studied by binding of lectins differing in sugar specificity.

Science.gov (United States)

Tsuda, M; Kurokawa, T; Takeuchi, M; Sugino, Y

1975-10-01

Changes in cell surface structure by viral transformation were studied by examining changes in the binding of various lectins differing in carbohydrate specificities. Binding of lectins was assayed directly using cells grown in coverslips. The following 125I-lectins were used: Concanavalin-A (specific for glucose and mannose), wheat germ agglutinin (specific for N-acetylglucosamine), castor bean agglutinin (specific for galactose), Wistaria floribunda agglutinin (specific for N-acetylgalactosamine), and soybean agglutinin (specific for N-acetyl-galactosamine). Cells for a clone, SS7, transformed by bovine adenovirus type-3, were found to bind 5 to 6 times more Wistaria floribunda agglutinin than the normal counterpart cells (clone C31, from C3H mouse kidney). In contrast, the binding of soybean agglutinin, which has a sugar specificity similar to Wistaria floribunda agglutinin, to normal and transformed cells was similar. The binding of wheat germ agglutinin and castor bean agglutinin, respectively, to normal and transformed cells was also similar. However, normal cells bound twice as much concanavalin-A as transformed cells. Only half as much Wistaria floribunda agglutinin was bound to transformed cells when they had been dispersed with EDTA. These changes in the number of lectin binding sites on transformation are thought to reflect alteration of the cell surface structure. The amount of lectins bound per cell decreased with increase in cell density, especially in the case of binding of Wistaria floribunda agglutinin to normal cells.

Microgramma vacciniifolia (Polypodiaceae) fronds contain a multifunctional lectin with immunomodulatory properties on human cells.

Science.gov (United States)

de Siqueira Patriota, Leydianne Leite; Procópio, Thamara Figueiredo; de Santana Brito, Jéssica; Sebag, Virginie; de Oliveira, Ana Patrícia Silva; de Araújo Soares, Ana Karine; Moreira, Leyllane Rafael; de Albuquerque Lima, Thâmarah; Soares, Tatiana; da Silva, Túlio Diego; Paiva, Patrícia Maria Guedes; de Lorena, Virgínia Maria Barros; de Melo, Cristiane Moutinho Lagos; de Albuquerque, Lidiane Pereira; Napoleão, Thiago Henrique

2017-10-01

In this study, we report the purification and characterization of a multifunctional lectin (MvFL) from Microgramma vacciniifolia fronds as well as its immunomodulatory properties on human peripheral blood mononuclear cells (PBMCs). MvFL (pI 4.51; 54kDa) is a glycoprotein able to inhibit trypsin activity and that has sequence similarities (32% coverage) with a plant RNA-binding protein. Hemagglutinating activity of MvFL was not altered by heating at 100°C for 30min, but was reduced in alkaline pH (8.0 and 9.0). Fluorimetric analyses showed that this lectin did not undergo marked conformational changes when heated. However, the MvFL conformation changed depending on the pH. MvFL at 6.25-25μg/mL was not cytotoxic to lymphocytes present among PBMCs. The PBMCs incubated for 24h with the lectin (12.5μg/mL) showed increased TNF-α, IFN-γ, IL-6, IL-10, and nitric oxide production. MvFL also stimulated T lymphocytes from PBMCs to differentiate into CD8 + cells. The activation (indicated by CD28 expression) of these cells was also stimulated. In conclusion, MvFL is a heat-stable and multifunctional protein, with both lectin and trypsin inhibitor activities, and capable of inducing predominantly a Th1 response in human PBMCs as well as activation and differentiation of T lymphocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

Circulating mannan-binding lectin, M-, L-, H-ficolin and collectin-liver-1 levels in patients with acute liver failure

DEFF Research Database (Denmark)

Laursen, Tea Lund; Sandahl, Thomas D; Støy, Sidsel

2015-01-01

BACKGROUND & AIMS: The complement system is activated in liver diseases including acute liver failure (ALF); however, the role of the lectin pathway of complement has scarcely been investigated in ALF. The pathway is initiated by soluble pattern recognition molecules: mannan-binding lectin (MBL),...

The photostability of the commonly used biotin-4-fluorescein probe.

Science.gov (United States)

Haack, Richard A; Swift, Kerry M; Ruan, Qiaoqiao; Himmelsbach, Richard J; Tetin, Sergey Y

2017-08-15

Biotin-4-fluorescein (B4F) is a commonly used fluorescent probe for studying biotin-(strept)avidin interactions. During a characterization study of an anti-biotin antibody, using B4F as the probe, we noticed a discrepancy in the expected and experimentally determined number of biotin binding sites. Analytical testing showed that the biotin moiety in the probe undergoes a photosensitized oxidation to produce a mixture of biotin sulfoxides which has the potential to impact the quantitation of binding sites using this fluorescent probe. Copyright © 2017 Elsevier Inc. All rights reserved.

Three-dimensional structure of lectin from Dioclea violacea and comparative vasorelaxant effects with Dioclea rostrata

Energy Technology Data Exchange (ETDEWEB)

Rocha, B.A.M.; Bezerra, M.J.B.; Bezerra, G.A.; Alencar, K.L.L.; Nascimento, K.S.; Naganao, C.S.; Sampaio, A.H.; Cavada, B.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Delatorre, P. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Rodrigues, N.V.; Pires, A.F.; Assreuy, A.M.S. [Universidade Estadual do Ceara (UECE), Fortaleza, CE (Brazil); Marins, J.L. [Universidade Federal de Pelotas (UFPel), Pelotas, RS (Brazil)

2012-07-01

Full text: Lectins are a structural heterogeneous group of proteins possessing at least one non-catalytic domain that binds reversibly to a specific mono or oligosaccharide. Diocleinae lectins exhibit glucose/mannose monosaccharide binding specificity and studies of their chemical and physicochemical properties revealed a high degree of identity in their amino acid sequences and three dimensional structures. This study investigated structural/functional relationships between lectins obtained from Dioclea violacea (DVL) and Dioclea rostrata (DRL). The purified lectin (DVL) was solubilized in 20 mM Tris-HCl pH 7.6 with 5 mM CaCl{sub 2} and MnCl{sub 2} buffer and incubated during one hour before the crystallization experiments with the ligand X-Man (5-bromo-4-chloro-3-indolyl-{alpha}-D-mannose) at 3 mM. Crystals of DVL grew in condition 33 of Crystal Screen I (4M Sodium formate) and belong to the orthorhombic space group I222. The structure of DVL at 2.6 resolution was obtained by molecular replacement using the coordinates of DRL (PDB code 2ZBJ), after the last refinement the structure presented R factor of 0.23 and R free of 0.27. The crystal structures reveal differences between them and could be related to relaxant activity. The conformation of residues HIS51, HIS131 and GLU205 and others positioned at CRD lead to different lectin binding activities. In fact, the pocket in DVL is small and deep and promotes weak interaction with carbohydrates, while DRL pocket is large and shallow, allowing strong interaction between CRD and sugars. This can explain why DVL and DRL elicited different degrees of aorta relaxation showing maximal effects of 43 % and 96 %, respectively. (author)

Fluorescein isothiocyanate (FITC)-Dextran Extravasation as a Measure of Blood-Brain Barrier Permeability

Science.gov (United States)

Natarajan, Reka; Northrop, Nicole

2017-01-01

The blood-brain barrier (BBB) is formed in part by vascular endothelial cells that constitute the capillaries and microvessels of the brain. The function of this barrier is to maintain homeostasis within the brain microenvironment and buffer the brain from changes in the periphery. A dysfunction of the BBB would permit circulating molecules and pathogens typically restricted to the periphery to enter the brain and interfere with normal brain function. As increased permeability of the BBB is associated with several neuropathologies, it is important to have a reliable and sensitive method that determines BBB permeability and the degree of BBB disruption. A detailed protocol is presented for assessing the integrity of the BBB by transcardial perfusion of a 10,000 Da FITC labeled dextran molecule and its visualization to determine the degree of extravasation from brain microvessels. PMID:28398646

Carbohydrate Microarray on Glass: a Tool for Carbohydrate-Lectin Interactions

NARCIS (Netherlands)

Tetala, K.K.R.; Giesbers, M.; Visser, G.M.; Sudhölter, E.J.R.; Beek, van T.A.

2007-01-01

A simple method to immobilize carbohydrates on a glass surface to obtain a carbohydrate microarray is described. The array was used to study carbohydrate-lectin interactions. The glass surface was modified with aldehyde terminated linker groups of various chain lengths. Coupling of carbohydrates

Preoperative mannan-binding lectin pathway and prognosis in colorectal cancer

DEFF Research Database (Denmark)

Ytting, Henriette; Christensen, Ib Jarle; Jensenius, Jens Christian

2005-01-01

PURPOSE: Deficiency of the mannan-binding lectin (MBL) pathway of innate immunity is associated with increased susceptibility to infections. In patients with colorectal cancer (CRC), postoperative infection is associated with poor prognosis. The aim of the present study was to evaluate (1...

Functionality screen of streptavidin mutants by non-denaturing SDS-PAGE using biotin-4-fluorescein.

Science.gov (United States)

Humbert, Nicolas; Ward, Thomas R

2008-01-01

Site-directed mutagenesis or directed evolution of proteins often leads to the production of inactive mutants. For streptavidin and related proteins, mutations may lead to the loss of their biotin-binding properties. With high-throughput screening methodologies in mind, it is imperative to detect, prior to the high-density protein production, the bacteria that produce non-functional streptavidin isoforms. Based on the incorporation of biotin-4-fluorescein in streptavidin mutants present in Escherichia coli bacterial extracts, we detail a functional screen that allows the identification of biotin-binding streptavidin variants. Bacteria are cultivated in a small volume, followed by a rapid treatment of the cells; biotin-4-fluorescein is added to the bacterial extract and loaded on an Sodium Dodecyl Sulfate Poly-Acrylamide Gel Electrophoresis (SDS-PAGE) under non-denaturing conditions. Revealing is performed using a UV transilluminator. This screen is thus easy to implement, cheap and requires only readily available equipment.

Macrophage galactose-type C-type lectin receptor for DC targeting of antitumor glycopeptide vaccines

DEFF Research Database (Denmark)

Nuti, M; Zizzari, I; Napoletano, C

2011-01-01

e13528 Background: Dendritic cells (DCs) are the most potent antigen presenting cells and are employed in cancer vaccination. Several receptors are being studied in order to identif strategies to increase DCs activating capacity. The C-type lectin macrophage galactose type C-type lectin (MGL...... of IFNg and IL-2 secretion by both CD8 and CD4 T cells. CONCLUSIONS: These results demonstrate that MGL engagement profoundly affects DC plasticity inducing and directing a Th1 immune response. Moreover, MGL receptor expressed on human DC can be targeted by glycopeptide based vaccines with adjuvant...

Lysophosphatidic acid stimulates thrombomodulin lectin-like domain shedding in human endothelial cells

International Nuclear Information System (INIS)

Wu Hualin; Lin ChiIou; Huang Yuanli; Chen, Pin-Shern; Kuo, Cheng-Hsiang; Chen, Mei-Shing; Wu, G.C.-C.; Shi, G.-Y.; Yang, H.-Y.; Lee Hsinyu

2008-01-01

Thrombomodulin (TM) is an anticoagulant glycoprotein highly expressed on endothelial cell surfaces. Increased levels of soluble TM in circulation have been widely accepted as an indicator of endothelial damage or dysfunction. Previous studies indicated that various proinflammatory factors stimulate TM shedding in various cell types such as smooth muscle cells and epithelial cells. Lysophosphatidic acid (LPA) is a bioactive lipid mediator present in biological fluids during endothelial damage or injury. In the present study, we first observed that LPA triggered TM shedding in human umbilical vein endothelial cells (HUVECs). By Cyflow analysis, we showed that the LPA-induced accessibility of antibodies to the endothelial growth factor (EGF)-like domain of TM is independent of matrix metalloproteinases (MMPs), while LPA-induced TM lectin-like domain shedding is MMP-dependent. Furthermore, a stable cell line expressing TM without its lectin-like domain exhibited a higher cell proliferation rate than a stable cell line expressing full-length TM. These results imply that LPA induces TM lectin-like domain shedding, which might contribute to the exposure of its EGF-like domain for EGF receptor (EGFR) binding, thereby stimulating subsequent cell proliferation. Based on our findings, we propose a novel mechanism for the exposure of TM EGF-like domain, which possibly mediates LPA-induced EGFR transactivation

Synthesis, crystal structure, and photoluminescence of a lithium isothiocyanate compound with 18-crown-6

Energy Technology Data Exchange (ETDEWEB)

Fu, Shan; Fu, Bo; Zhao, Zhen; Liu, Xi [Chongqing Normal Univ. (China). Chongqing Key Lab. of Inorganic Functional Materials

2018-04-01

The investigation of the supramolecular interactions between the lithium isothiocyanate salt and 18-crown-6 (18C-6) in commercial tetrahydrofuran leads to the formation of a lithium compound, LiNCS(H{sub 2}O)(18C-6) (1). In the crystal structure the asymmetric unit contains two similar LiNCS(H{sub 2}O)(18C-6) molecules. Solid-state photoluminescence experiments have shown that compound 1 emits violet luminescence, and its possible emission mechanism was investigated in detail based on theoretical calculations.

Comparison of the nature of interactions of two sialic acid specific lectins Saraca indica and Sambucus nigra with N-acetylneuraminic acid by spectroscopic techniques

Energy Technology Data Exchange (ETDEWEB)

Singha, Shuvendu [Department of Natural Science, West Bengal University of Technology, Kolkata 700064 (India); Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700032 (India); Bose, Partha P. [Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844101 (India); Ganguly, Tapan [School of Laser Science and Engineering, Jadavpur University, Jadavpur, Kolkata 700032 (India); Campana, Patricia T. [Escola de Artes, Ciências e Humanidades, Universidade de São Paulo, 03828-000 São Paulo (Brazil); Ghosh, Rina [Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700032 (India); Chatterjee, Bishnu P., E-mail: cbishnup@gmail.com [Department of Natural Science, West Bengal University of Technology, Kolkata 700064 (India)

2015-04-15

The present paper deals with the isolation and purification of a new sialic acid binding lectin from the seed integument of Saraca indica (Ashok) and the purified lectin was designated Saracin II. Comparative studies on the interactions of saracin II and another sialic acid specific lectin Sambucus nigra agglutinin (SNA) with N-acetylneuraminic acid (NANA) were made using UV–vis absorption, steady state and time resolved fluorescence along with circular dichroism (CD) spectroscopy to reveal the nature and mechanisms of binding of these two lectins with NANA. The experimental observations obtained from UV–vis, steady state and time resolved fluorescence measurements demonstrated that SNA–NANA system formed relatively stronger ground state complex than saracin II–NANA pair. CD measurements further substantiated the propositions made from steady state and time resolved spectroscopic investigations. It was inferred that during interaction of SNA with NANA, the lectin adopted a relatively looser conformation with the extended polypeptide structures leading to the exposure of the hydrophobic cavities which favoured stronger binding with NANA. - Highlights: • Of the two lectins, stronger binding of SNA with NANA is observed. • Full exposure of the hydrophobic cavities of SNA favors the stronger interactions. • Saracin II can be used for the new generation of lectin based-therapeutics.

Label-free detection of glycoproteins by the lectin biosensor down to attomolar level using gold nanoparticles

Science.gov (United States)

Bertok, Tomas; Sediva, Alena; Katrlik, Jaroslav; Gemeiner, Pavol; Mikula, Milan; Nosko, Martin; Tkac, Jan

2016-01-01

We present here an ultrasensitive electrochemical biosensor based on a lectin biorecognition capable to detect concentrations of glycoproteins down to attomolar (aM) level by investigation of changes in the charge transfer resistance (Rct) using electrochemical impedance spectroscopy (EIS). On polycrystalline gold modified by an aminoalkanethiol linker layer, gold nanoparticles were attached. A Sambucus nigra agglutinin was covalently immobilised on a mixed self-assembled monolayer formed on gold nanoparticles and finally, the biosensor surface was blocked by poly(vinylalcohol). The lectin biosensor was applied for detection of sialic acid containing glycoproteins fetuin and asialofetuin. Building of a biosensing interface was carefully characterised by a broad range of techniques such as electrochemistry, EIS, atomic force microscopy, scanning electron microscopy and surface plasmon resonance with the best performance of the biosensor achieved by application of HS-(CH2)11-NH2 linker and gold nanoparticles with a diameter of 20 nm. The lectin biosensor responded to an addition of fetuin (8.7% of sialic acid) with sensitivity of (338 ± 11) Ω decade-1 and to asialofetuin (≤ 0.5% of sialic acid) with sensitivity of (109 ± 10) Ω decade-1 with a blank experiment with oxidised asialofetuin (without recognisable sialic acid) revealing sensitivity of detection of (79 ± 13) Ω decade-1. These results suggest the lectin biosensor responded to changes in the glycan amount in a quantitative way with a successful validation by a lectin microarray. Such a biosensor device has a great potential to be employed in early biomedical diagnostics of diseases such as arthritis or cancer, which are connected to aberrant glycosylation of protein biomarkers in biological fluids. PMID:23601864

Serum levels of mannan-binding lectin in chickens prior to and during experimental infection with avian infectious bronchitis virus

DEFF Research Database (Denmark)

Juul-Madsen, H.R.; Munch, M.; Handberg, Kurt

2003-01-01

Mannan-binding lectin (MBL) is a glycoprotein and a member of the C-type lectin super family, the collectin family, and the acute phase protein family. The MBL exerts its function by directly binding to microbial surfaces through its carbohydrate recognition domains, followed by direct opsonizati...

Mannose-binding lectin (MBL2) and ficolin-2 (FCN2) polymorphisms in patients on peritoneal dialysis with staphylococcal peritonitis

NARCIS (Netherlands)

Meijvis, Sabine C. A.; Herpers, Bjorn L.; Endeman, Henrik; de Jong, Ben; van Hannen, Erik; van Velzen-Blad, Heleen; Krediet, Raymond T.; Struijk, Dirk G.; Biesma, Douwe H.; Bos, Willem Jan W.

Background. Mannose-binding lectin (MBL) and ficolin-2 (FCN) are activators of the lectin pathway of complement and act as primary defences against infection. Single-nucleotide polymorphisms (SNPs) in the MBL2 and FCN2 genes influence the functionality of the proteins. Both proteins are capable of

The immunomodulatory effect of plant lectins: a review with emphasis on ArtinM properties.

Science.gov (United States)

Souza, Maria A; Carvalho, Fernanda C; Ruas, Luciana P; Ricci-Azevedo, Rafael; Roque-Barreira, Maria Cristina

2013-10-01

Advances in the glycobiology and immunology fields have provided many insights into the role of carbohydrate-protein interactions in the immune system. We aim to present a comprehensive review of the effects that some plant lectins exert as immunomodulatory agents, showing that they are able to positively modify the immune response to certain pathological conditions, such as cancer and infections. The present review comprises four main themes: (1) an overview of plant lectins that exert immunomodulatory effects and the mechanisms accounting for these activities; (2) general characteristics of the immunomodulatory lectin ArtinM from the seeds of Artocarpus heterophyllus; (3) activation of innate immunity cells by ArtinM and consequent induction of Th1 immunity; (4) resistance conferred by ArtinM administration in infections with intracellular pathogens, such as Leishmania (Leishmania) major, Leishmania (Leishmania) amazonensis, and Paracoccidioides brasiliensis. We believe that this review will be a valuable resource for more studies in this relatively neglected area of research, which has the potential to reveal carbohydrate targets for novel prophylactic and therapeutic strategies.

Concentration- and Time-Dependent Effects of Isothiocyanates Produced from Brassicaceae Shoot Tissues on the Pea Root Rot Pathogen Aphanomyces euteiches

NARCIS (Netherlands)

Hossain, S.; Bergkvist, G.; Berglund, K.; Glinwood, R.; Kabouw, P.; Martensson, A.; Persson, P.

2014-01-01

Isothiocyanates (ITCs) hydrolyzed from glucosinolates (GSLs) in Brassicaceae tissue are toxic to soil organisms. In this study, the effect of aliphatic and aromatic ITCs from hydrated dry Brassicaceae shoot tissues on the mycelium and oospores of the pea root rot pathogen Aphanomyces euteiches was

Human surfactant protein D: SP-D contains a C-type lectin carbohydrate recognition domain.

Science.gov (United States)

Rust, K; Grosso, L; Zhang, V; Chang, D; Persson, A; Longmore, W; Cai, G Z; Crouch, E

1991-10-01

Lung surfactant protein D (SP-D) shows calcium-dependent binding to specific saccharides, and is similar in domain structure to certain members of the calcium-dependent (C-type) lectin family. Using a degenerate oligomeric probe corresponding to a conserved peptide sequence derived from the amino-terminus of the putative carbohydrate binding domain of rat and bovine SP-D, we screened a human lung cDNA library and isolated a 1.4-kb cDNA for the human protein. The relationship of the cDNA to SP-D was established by several techniques including amino-terminal microsequencing of SP-D-derived peptides, and immunoprecipitation of translation products of transcribed mRNA with monospecific antibodies to SP-D. In addition, antibodies to a synthetic peptide derived from a predicted unique epitope within the carbohydrate recognition domain of SP-D specifically reacted with SP-D. DNA sequencing demonstrated a noncollagenous carboxy-terminal domain that is highly homologous with the carboxy-terminal globular domain of previously described C-type lectins. This domain contains all of the so-called "invariant residues," including four conserved cysteine residues, and shows high homology with the mannose-binding subfamily of C-type lectins. Sequencing also demonstrated an amino-terminal collagenous domain that contains an uninterrupted sequence of 59 Gly-X-Y triplets and that also contains the only identified consensus for asparagine-linked oligosaccharides. The studies demonstrate that SP-D is a member of the C-type lectin family, and confirm predicted structural similarities to conglutinin, SP-D, and the serum mannose binding proteins.

Mannose-Binding Lectin Binds to Amyloid Protein and Modulates Inflammation