Literatura académica sobre el tema "Lectins"
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Artículos de revistas sobre el tema "Lectins"
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Ogilvie, Mary L., JoAnn Wilson Byl, and T. Kent Gartner. "Platelet Aggregation Is Stimulated by Lactose-lnhibitable Snake Venom Lectins." Thrombosis and Haemostasis 62, no. 02 (1989): 704–7. http://dx.doi.org/10.1055/s-0038-1646887.
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SummaryFive lactose-specific lectins from snake venoms were tested for the ability to stimulate the aggregation of human platelets. Three of the lectins, bushmaster (Lachesis muta), cottonmouth (Aricistrodon piscivorous leukostoma) and rattlesnake (Crotalus atrox) lectins, consistently stimulated secretion and aggregation. Thrombolectin (Bothrops atrox) occasionally caused aggregation. Copperhead (Agkistrodon contortrix contortrix) lectin did not by itself cause platelet aggregation. Lactose, a specific inhibitor of hemagglutination mediated by these lectins was a potent inhibitor of lectin-induced aggregation. Antiserum specific for bushmaster lectin inhibited aggregation by bushmaster lectin. In contrast, the same antiserum and anti-cottonmouth lectin serum enhanced aggregation by low levels of the other lectins.A variety of substances were assayed in the aggregometer for the ability to inhibit aggregation in response to these lectins. Both secretion and aggregation were inhibited by PGI2 and PGEx. Furthermore, lectin-induced aggregation was completely blocked by trifluoperazine and partially blocked by indomethacin. Monoclonal antibodies specific for GP IIb/IIIa (AP2, A2A9, LJP5, LJCP8) but not monoclonals directed against other platelet membrane proteins (API and AP3) inhibited lectin-induced aggregation. The peptide Arg-Gly-Asp-Ser but not Arg-Ala-Asp-Ser was a potent inhibitor of aggregation.
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Kothari, Sajani, Rebecca Heineman, and Rene Harrison. "Optimizing Lectin Staining Methodology to Assess Glycocalyx Composition of Legionella-Infected Cells." Undergraduate Research in Natural and Clinical Science and Technology (URNCST) Journal 7, no. 7 (July 17, 2023): 1–10. http://dx.doi.org/10.26685/urncst.490.
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Introduction: Legionella is a gram-negative bacterium that replicates intracellularly within macrophages. Legionella utilizes effector proteins to hijack ER-Golgi vesicle trafficking to sustain proliferation in its intracellular niche. Legionella has a considerable influence on O-glycosylation but not N-glycosylation events in the Golgi of infected cells. This research aims to optimize the use of fluorescent lectins, which are proteins that bind carbohydrates, to effectively label host-cell glycocalyx during Legionella infection. Methods: Epifluorescence imaging or flow cytometry were used to optimize the lectin staining methodology. We noted that the most effective conditions for lectin-labeling were when live HeLa cells were incubated with lectins diluted in Hank’s balanced salt solution (HBSS) with 3% Bovine serum albumin (BSA) for 10-30 minutes at 4 °C. Results: Incubating suspended cells with lectins necessitated smaller lectin concentrations, whereas lectin labeling of adherent cells required considerably larger concentrations. Wheat germ agglutinin (WGA) lectin mean fluorescence intensity (MFI) was concentration-dependent, but Concanavalin A (ConA) and Maclura pomifera (MPA) MFIs did not alter substantially with increasing lectin concentrations. Discussion: The optimal lectin concentration required was lectin-specific and based on whether the lectin fluorescence was assessed using flow cytometry or epifluorescence. Furthermore, the use of phosphate-buffered saline (PBS) for lectin dilution, cell permeabilization for intracellular labelling, and incubation of lectins in fixed cells reduced productive labelling of lectins on cell surfaces because it inhibited the lectin's ability to effectively bind the associated carbohydrate structure. Conclusion: Further research using diverse lectins on U937 macrophages is necessary to reach a definitive conclusion on the effect of Legionella on the overall host-cell glycocalyx composition during infection of these relevant immune cells.
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Bonnardel, François, Julien Mariethoz, Serge Pérez, Anne Imberty, and Frédérique Lisacek. "LectomeXplore, an update of UniLectin for the discovery of carbohydrate-binding proteins based on a new lectin classification." Nucleic Acids Research 49, no. D1 (November 11, 2020): D1548—D1554. http://dx.doi.org/10.1093/nar/gkaa1019.
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Abstract Lectins are non-covalent glycan-binding proteins mediating cellular interactions but their annotation in newly sequenced organisms is lacking. The limited size of functional domains and the low level of sequence similarity challenge usual bioinformatics tools. The identification of lectin domains in proteomes requires the manual curation of sequence alignments based on structural folds. A new lectin classification is proposed. It is built on three levels: (i) 35 lectin domain folds, (ii) 109 classes of lectins sharing at least 20% sequence similarity and (iii) 350 families of lectins sharing at least 70% sequence similarity. This information is compiled in the UniLectin platform that includes the previously described UniLectin3D database of curated lectin 3D structures. Since its first release, UniLectin3D has been updated with 485 additional 3D structures. The database is now complemented by two additional modules: PropLec containing predicted β-propeller lectins and LectomeXplore including predicted lectins from sequences of the NBCI-nr and UniProt for every curated lectin class. UniLectin is accessible at https://www.unilectin.eu/
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Lakhtin, M., V. Lakhtin, V. Alyoshkin, and S. Afanasyev. "Lectins of beneficial microbes: system organisation, functioning and functional superfamily." Beneficial Microbes 2, no. 2 (June 1, 2011): 155–65. http://dx.doi.org/10.3920/bm2010.0014.
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In this review our last results and proposals with respect to general aspects of lectin studies are summarised and compared. System presence, organisation and functioning of lectins are proposed, and accents on beneficial symbiotic microbial lectins studies are presented. The proposed general principles of lectin functioning allows for a comparison of lectins with other carbohydrate-recognition systems. A new structure-functional superfamily of symbiotic microbial lectins is proposed and its main properties are described. The proposed superfamily allows for extended searches of the biological activities of any microbial member. Prospects of lectins of beneficial symbiotic microorganisms are discussed.
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Melgarejo, Luz Marina, Nohora Vega, and Gerardo Pérez. "Isolation and characterization of novel lectins from Canavalia ensiformis DC and Dioclea grandiflora Mart. ex Benth. seeds." Brazilian Journal of Plant Physiology 17, no. 3 (September 2005): 315–24. http://dx.doi.org/10.1590/s1677-04202005000300006.
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Two lectins were isolated from Canavalia ensiformis and Dioclea grandiflora seeds. Gel filtration produced a fraction corresponding to Con A or D. grandiflora lectin while erythroagglutination assays revealed a distinct fraction presenting a lectin that agglutinates human red blood cells (RBCs) but not rabbit RBCs. Hydrophobic interaction chromatography showed that the latter fraction yielded a protein that readily agglutinates human erythrocytes; the lectin was also purified by affinity chromatography on Lac-Sepharose showing similar properties to that of the Phenyl-Sepharose-purified lectin. Despite minor differences (carbohydrate content or A1%1cm), the two lectins showed similar molecular properties in that they consisted of two non-covalently linked monomers having a Mr of 29-30 kDa and their pI values indicated that both lectins were slightly acidic proteins. The C. ensiformis lectin (CEL-II) and D. grandiflora lectin (DGL-II) specifically recognised the H-type 2 blood group (alpha-L-Fuc (1-2)-beta-D-Gal (1-4)-beta-D-GlcNAc-O-R), while binding to H-type 1, H-type 3, H-type 4, Leª or Le y was weaker. Carbohydrate inhibition of erythroagglutination showed that simple sugars were weakly recognised by the lectins, if at all. The N-terminal region presented a unique sequence hitherto found only in some Diocleinae lectins (designated type II). The overall results confirmed the existence of a second distinct lectin type, phylogenetically close to Diocleinae species. The data indicate a functional similarity among lectins of this type which possesses distinctive characteristics differentiating them from "classical" Man/Glc lectins.
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Ideo, Hiroko, Akiko Tsuchida, and Yoshio Takada. "Lectin-Based Approaches to Analyze the Role of Glycans and Their Clinical Application in Disease." International Journal of Molecular Sciences 25, no. 18 (September 23, 2024): 10231. http://dx.doi.org/10.3390/ijms251810231.
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Lectin-based approaches remain a valuable tool for analyzing glycosylation, especially when detecting cancer-related changes. Certain glycans function as platforms for cell communication, signal transduction, and adhesion. Therefore, the functions of glycans are important considerations for clinical aspects, such as cancer, infection, and immunity. Considering that the three-dimensional structure and multivalency of glycans are important factors for their function, their binding characteristics toward lectins provide vital information. Glycans and lectins are inextricably linked, and studies on lectins have also led to research on the roles of glycans. The applications of lectins are not limited to analysis but can also be used as drug delivery tools. Moreover, mammalian lectins are potential therapeutic targets because certain lectins change their expression in cancer, and lectin regulation subsequently regulates several molecules with glycans. Herein, we review lectin-based approaches for analyzing the role of glycans and their clinical applications in diseases, as well as our recent results.
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Van Holle, Sofie, and Els J. M. Van Damme. "Signaling through plant lectins: modulation of plant immunity and beyond." Biochemical Society Transactions 46, no. 2 (February 22, 2018): 217–33. http://dx.doi.org/10.1042/bst20170371.
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Lectins constitute an abundant group of proteins that are present throughout the plant kingdom. Only recently, genome-wide screenings have unraveled the multitude of different lectin sequences within one plant species. It appears that plants employ a plurality of lectins, though relatively few lectins have already been studied and functionally characterized. Therefore, it is very likely that the full potential of lectin genes in plants is underrated. This review summarizes the knowledge of plasma membrane-bound lectins in different biological processes (such as recognition of pathogen-derived molecules and symbiosis) and illustrates the significance of soluble intracellular lectins and how they can contribute to plant signaling. Altogether, the family of plant lectins is highly complex with an enormous diversity in biochemical properties and activities.
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Mewe, Marco, Denis Tielker, Robert Schönberg, Melitta Schachner, Karl-Erich Jaeger, and Udo Schumacher. "Pseudomonas aeruginosa lectins I and II and their interaction with human airway cilia." Journal of Laryngology & Otology 119, no. 8 (August 2005): 595–99. http://dx.doi.org/10.1258/0022215054516313.
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The bacterium Pseudomonas aeruginosa (PA) produces two carbohydrate binding lectins, designated PA lectin-I and lectin-II (PA-IL, PA-IIL). Both lectins are used by the bacterium to adhere to the glycocalyx of mammalian cells. In addition, the lectins immobilize ciliary beat. The kinetics of ciliary beat inhibition by each individual lectin have been analysed; however, their joint action on cilia has not been reported. Here we demonstrate that PA-IL and PA-IIL inhibit ciliary beat in a similar time-dependent manner. If applied simultaneously, ciliary beat inhibition after five hours of incubation was weaker than if each lectin was applied separately. Thus it can be hypothesized that the lectins compete for the same binding site(s) of the glycocalyx. Sugar inhibition experiments demonstrate that D-galactose and L-fucose inhibit both lectins, although clear preferences of D-galactose for PA-IL and of L-fucose for PA-IIL exist. These interactions have to be kept in mind when designing sugar-based therapies.
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Lesman-Movshovich, Efrat, Batia Lerrer, and Nechama Gilboa-Garber. "Blocking ofPseudomonas aeruginosalectins by human milk glycans." Canadian Journal of Microbiology 49, no. 3 (March 1, 2003): 230–35. http://dx.doi.org/10.1139/w03-027.
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The opportunistic human pathogen Pseudomonas aeruginosa produces a D-galactophilic (PA-IL) lectin and another lectin (PA-IIL) that binds L-fucose > D-arabinose > D-mannose in close association with its host-attacking factors. These lectins contribute to the virulence of P. aeruginosa by their involvement in the production, adhesion, and pathogenic effects of its biofilm on host cells. Therefore, they are considered targets for anti-Pseudomonas therapy. The present study compares their blocking by human milk samples with that of the plant lectin Con A. It demonstrates that human milk inhibits the hemagglutinating activities of the three lectins, with PA-IIL much more strongly inhibited than PA-IL or Con A. Using these lectins, Western blots of the milk samples accord with the hemagglutination inhibition data and disclose the distribution of the human milk glycoproteins that inhibit each lectin. The data of this paper reveal the high efficiency of human milk components in blocking the P. aeruginosa lectins and the usefulness of these lectins for detecting milk glycoprotein saccharides, which may protect the infant against infections.Key words: Pseudomonas aeruginosa, lectins, human milk, glycoproteins, Western blotting.
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Coelho, Luana Cassandra Breitenbach Barroso, Priscila Marcelino dos Santos Silva, Vera Lúcia de Menezes Lima, Emmanuel Viana Pontual, Patrícia Maria Guedes Paiva, Thiago Henrique Napoleão, and Maria Tereza dos Santos Correia. "Lectins, Interconnecting Proteins with Biotechnological/Pharmacological and Therapeutic Applications." Evidence-Based Complementary and Alternative Medicine 2017 (2017): 1–22. http://dx.doi.org/10.1155/2017/1594074.
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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.
Tesis sobre el tema "Lectins"
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Lucca, Rosemeire Aparecida da Silva de. "Propriedades físico-químicas da lectina KM+ monitoradas por dicroismo circular (CD) e fluorescência. Estimativa do conteúdo de estrutura secundaria por CD." Universidade de São Paulo, 1994. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-02042014-100315/.
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Uma nova lectina extraída da semente de Artocarpus integrifólia, denominada KM+ foi recentemente descrita. KM+ e haptotática para neutrófilos, promove a aglutinação de hemácias dos grupos A, B, 0, estimula a proliferação de linfócitos do baço de camundongos e liga-se em α D-manose, α metil manosidio e α D-glicose. Esta lectina é composta por quatro monômeros, com peso molecular de 13.150 daltons cada, unidos por interações não covalentes. KM+ contem 1,8% de carboidratos e apresentou quatro isoformas com pontos isoelétricos entre 4,2 e 5,2. Este trabalho teve como objetivos estudar modificações estruturais de KM+ em função de parâmetros como temperatura, força iônica, pH, agentes desnaturantes, ligação com D-manose, monitoradas por dicroísmo circular (CD) e fluorescência. CD também foi utilizado para estimar o conteúdo de estrutura secundaria de KM+, utilizando-se dois programas descritos na literatura: SSE (Secondary Structure Estimation), que utiliza o método dos mínimos quadrados para a estimativa da estrutura secundaria e obtenção dos espectros básicos, baseados nos dados cristalográficos de proteínas de .estrutura resolvida; CCA (Convex Constraint Analisys) que utiliza o algoritmo simplex e a partir dos espectros de CD das proteínas de referencia calcula os espectros das componentes básicas. Para a estimativa das frações de estrutura secundária o segundo método utiliza o programa Lincomb. Os espectros de CD foram registrados no intervalo de 185 a 260 nm. O conteúdo em estrutura secundária, estimado pelo programa SSE foi: 0% de α-hélice, 41% de folha β, 27% de volta β e 32,3 de estrutura desordenada; pelo programa CCA foi: 1% de α-hélice, 35% de folha β anti-paralela, 21% de volta β e/ou folha β paralela, 15% de contribuições de aromáticos e/ou ligações dissulfeto, 28% de estrutura desordenada. Os desvios médios quadráticos para os programas SSE e CCA foram 12% e 1%, respectivamente. Portanto a lectina KM+ é principalmente constituída por estruturas tipo folha β e tipo desordenada. A curva calculada pelo programa CCA foi mais bem estimada, pois tem o desvio médio quadrático 12 vezes menor que o do programa SSE. Este resultado, provavelmente ocorre devido aos seguintes fatores: (i) no programa CCA, o espectro da proteína a ser analisada e alinhado com os espectros das proteínas de referência, influenciando no calculo dos espectros básicos; (ii) maior número de proteínas com estrutura β no grupo de referência do programa CCA. A estabilidade de KM+ em função da temperatura tem comportamento diferente em tampão sódio fosfato (PBS) daquele observado em água. Em PBS, quando a amostra esta a 70°C, a forma do espectro de CD mostrou-se consistente com um espectro de proteína desnaturada. Comumente, um espectro de proteína desnaturada caracteriza-se pela perda da estrutura secundaria predominante e aumento da estrutura desordenada. Em água, também a 70°C, na região da estrutura β (216 nm) surge uma nova banda e na região da estrutura desordenada (195 nm) aparece uma banda com valores positivos mimetizando um espectro da estrutura α-hélice. Esta diferença de comportamento pode ser devida à força iônica. A desorganização promovida na molécula de KM+ por cloreto de guanidina foi típica de desnaturação. o máximo da emissão de fluorescência, da KM+ em PBS pH 7,2, foi a 328 nm, característico de resíduos de triptofano protegidos do solvente. Este máximo mudou para 340 nm em pH 10,5. Este resultado indica mudanças no ambiente químico do triptofano neste pH. O deslocamento para a região do vermelho indica, que em pH. os resíduos de triptofano estio em maior contato com o solvente. O número de sitios ligantes de D-manose J)a molécula de KM+, foi estimado pela supressão da fluorescência promovida pelo D-manose. Esta estimativa foi baseada na suposição de que todos os sítios ligantes de D-manose estivessem próximos aos resíduos de triptofano. A relação encontrada foi de 2 moles de D-manose/mol de KM+<br>Recently a new lectin, KM+, isolated from Artocarpus integrifolia seeds was described. KM+ induces neutrophil migration, agglutination of human red blood cells, proliferation of mouse spleen cells and binding with monosacharides D-mannose, D-glicose and α-metil mannoside. This glycoprotein is composed of four monomers, assembled by non covalent bonds, has 500 aminoacids residues/mol, with a Molecular Weight of 52,000 Daltons and 1.8% of carbohydrates [27]. In this work structural changes of KM+ was studied as a function of temperature, pH, chemical denaturing agents as well as the binding with D-mannose. These changes were monitored by circular dichroism (CD) and fluorimetry. Circular Dichroism (CD) spectroscopy was used for the analysis of the secondary structure of KM+ in solution due do its capacity to indicate the presence and to estimate the proportion of α-helix, β-sheet, β-turn and unordered conformations. This measurent can be regarded as a function of the relative orientation of the chromophores responsible for their chiroptical activity. CD spectroscopy is also one of the methods of choice for monitorization of conformational changes in proteins as a function of solvents, pH, temperature, ionic strength and specific or non specific binding. Two programs which are in use for estimation of secondary structure: SSE, using the linear least squares method and CCA, using the simplex method, were evaluated in the present work. SSE uses a set of proteins with known X-ray data as the basis for evaluation while CCA uses only pure proteins experimental CD spectra. Fluorescence spectroscopy is very useful to monitore of protein conformational changes in solution due to the presence of intrinsic fluorophores. Fluorescence Measurements were performed at 25°C. Samples were excited at 280 nm and the emission was monitored in the range 290-450 nm. The maximum emission as a function of pH was at pH 7.0. The wavelength for maximum emission changed from 328 nm at pH 7.0 to 340 nm at pH 10.5. CD spectra were recorded over the range of 185 up to 260 nm. The Secondary structure content estimated by SSE program was: 0% α-helix, 41% β-sheet, 26% β-turn and 32% random with RMS of 12% and CCA program was: 1% α-helix, 35% antiparallel β-sheet, 21% β-turn and/or parallel B-sheet, 28% random, 15% aromatics contributions and dissulfide linkages with RMS of 1%. The fractions of secondary structure obtained when using CCA program were more consistent than those of SSE program. The simulation by CCA program was better probably due to its desconvolution of the spectral contribution of the common secondary structures using experimental CD curves of proteins. The stability of KM+, in PBS, as a function of temperature changes above 55°C but only at 70°C the shape of the CD spectrum is consistent with the loss of the native ordered secondary structure that should accompany protein unfolding. CD spectra of KM+ in water showed conformational changes as a function of temperature was not consistent with denaturated proteins. The unfolding of KM+ by GdnCl and SDS resulted in CD spectroscopic changes: consistent with the increased random structure and disappearance of beta sheet. Using the two denaturing agents together GdnCl and temperature, the denaturation was observed at lower decreased both GdnCl concentration and at lower temperature. The estimation of the number of binding sites for D-mannose was obtained through the fluorescence intensity decrease due to a quenching effect of D-mannose and showed that the stoichiometry of binding was 2 moles of D-mannoseimol of lectin
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Silva, Luana Maria Castelo Melo. "Efeito da lectina da alga marinha vermelha Pterocladiella capillace em feridas limpas induzidas em ratos." reponame:Repositório Institucional da UFC, 2012. http://www.repositorio.ufc.br/handle/riufc/18834.
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SILVA, Luana Maria Castelo Melo. Efeito da lectina da alga marinha vermelha Pterocladiella capillace em feridas limpas induzidas em ratos. 2012. 135 f. Tese (Doutorado em bioquímica)- Universidade Federal do Ceará, Fortaleza-CE, 2012.<br>Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-07-20T16:16:36Z
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Previous issue date: 2012<br>Based on the need for new formulations that are more efficient and on the properties provided by molecules derived from seaweed, it is believed that these can be effective in healing process. The lectin from the red seaweed Pterocladiella capillacea (PcL) and the polysaccharides of red algae Solieria filiformis (SfP) were initially analyzed in toxicity testing. PcL was applied to the paw edema test followed by measurement of myeloperoxidase (MPO). We evaluated the effect of the seaweed Pterocladiella capillacea lectin (PcL) and algal polysaccharides Solieria filiformis (SfP) in healing wounds in rats induced. Both molecules were submitted to microbiological tests and assayed for the effect on wound healing in wounds clean induced on the back of rats. SfP was used as a possible vehicle for the administration of PcL and compared to Carbopol 940 (C). The gels (0.9%) were analyzed rheological and then applied to the lesions during a treatment period of 10 days, using kollagenase ® as control. The healing process was evaluated on the size of the wounds, levels of MPO and histological analysis. The molecule SfP and PcL is not toxic for the parameters of body weight, organ and biochemical measurements. However, the histological analysis showed minor changes in liver and kidney. PcL (1, 3 and 9 mg / kg, i.v) reduced the edema induced by carrageenan and its inhibitor when administered with mucin was not possible to check the reduction of edema which was confirmed by measurement of MPO. The two molecules were used in microbiological assays and not inhibit growth of any microorganism tested and unable to use SfP as carbon source. The rheological analysis showed that the SfP used in the formulation of the gels (PcL+SfP and SfP) had the characteristic of a pseudoplastic. Macroscopic analysis of wounds showed a reduction in lesion area in the animals treated with PCL, PCL+SfP, PCL+C (53.5 and 60% respectively) on the sixth day of administration. In histological analysis, there was no severe inflammatory infiltrate in the tissues obtained until 4th day of administration of the gels (PcL and PcL+SfP, PcL+C) and Kollagenase® (positive control). On day 6, the untreated animals and those treated only with SfP showed inflammatory infiltrate. The measurement of MPO showed a reduction in the inflammatory process in the samples containing PcL, whose results corroborate the histological analysis. In conclusion, PcL aid in wound repair, suggesting its use as a possible future tool for the treatment of lesions. The biological and pharmacological role of lectins and polysaccharides of seaweed is part of a study area little explored, where a lot of knowledge should be invested since these biomolecules can be promising for the pharmaceutical industry.<br>Com base na necessidade de obter novas formulações mais eficientes e diante das propriedades apresentadas pelas moléculas oriundas de algas marinhas, acredita-se que estas possam ser eficazes no processo de cicatrização. A lectina da alga marinha vermelha Pterocladiella capillacea (PcL) e os polissacarídeos da alga vermelha Solieria filiformis (SfP) inicialmente foram analisados em ensaio de toxicidade. PcL foi aplicada no ensaio do edema de pata seguido da dosagem de mieloperoxidase (MPO). Avaliou-se o efeito da lectina da alga Pterocladiella capillacea (PcL) e os polissacarídeos das algas Solieria filiformis (SfP) na cicatrização de feridas induzidas em ratos. Ambas as moléculas foram submetidas a ensaios microbiológicos e analisadas quanto ao efeito no processo de cicatrização em feridas limpas induzidas no dorso de ratos. SfP foi utilizado como um possível veículo para a administração de PcL e comparado ao Carbopol 940 (C). Os géis (0,9%) foram submetidos a análise reológica e então aplicados nas lesões durante um período de tratamento de 10 (dez) dias, utilizando kollagenase® como controle. O processo de cicatrização foi avaliado quanto ao tamanho das feridas, dosagem de MPO e análise histológica. PcL e SfP não demonstraram toxicidade quanto aos parâmetros de peso corpóreo, órgãos e dosagens bioquímicas. Entretanto a análise histológica mostrou pequenas alterações no fígado e rim. PcL (1, 3 e 9 mg/kg, i.v.) reduziu o edema induzido por carragenana e quando administrada com seu inibidor mucina não foi possível verificar a redução do edema o qual foi confirmado pela dosagem de MPO. As duas moléculas foram aplicadas em ensaios microbiológicos e não inibiram o crescimento de nenhum micro-organismo testado, os quais também não foram capazes de utilizar SfP como fonte de carbono. A análise reológica mostrou que os SfP utilizados na formulação dos géis (PcL+SfP e SfP) apresentaram a característica de um pseudoplástico. A análise macroscópica das feridas mostrou uma redução da área da lesão nos animais tratados com PcL+SfP e PcL+C (53,5 e 60%, respectivamente) no sexto dia de administração. Na análise histológica, não foi observado infiltrado inflamatório acentuado nos tecidos obtidos até o 4º dia da administração dos géis (PcL+SfP e PcL+C) e Kollagenase® (controle positivo). No 6º dia, os animais não tratados e os tratados apenas com SfP mostraram infiltrado inflamatório. A dosagem de MPO demonstrou redução no processo inflamatório nas amostras contendo PcL, cujo resultado corrobora com a análise histológica. Em conclusão, PcL auxiliou no reparo de feridas, sugerindo seu uso futuro como uma possível ferramenta para o tratamento de lesões. O papel biológico e farmacológico das lectinas e polissacarídeos de algas marinhas faz parte de uma área de estudos ainda pouco explorada, onde muito conhecimento deverá ser investido visto que estas biomoléculas podem ser promissoras para a indústria farmacêutica.
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Oliveira, Wilian Rosário de. "Lectinas de Crotalaria spectabilis R.: isolamento, purificação e atividade aglutinante em Leptospira biflexa (saprófita) e L. interrogans (patogênica)." Instituto de Ciências da Saúde, 2014. http://repositorio.ufba.br/ri/handle/ri/23507.
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Dissertação Final- WILIAN OLIVEIRA.pdf: 1510952 bytes, checksum: 9058b21042c585177d09b07cc902395e (MD5)<br>CAPES<br>Lectinas são proteínas que se ligam especificamente a resíduos de açúcar e estão envolvidas no processo de reconhecimento celular e sinalização em diversas vias metabólicas. O objetivo deste estudo foi isolar, purificar e investigar a atividade biológica das lectinas de Crotalaria spectabilis R. quanto a sua capacidade de hemaglutinação e aglutinação das linhagens bacterianas: Leptospira biflexa e L. interrogans. Para extração das proteínas, as sementes foram moídas e suas células lisadas em solução NaCl 0,15 M. Após essa etapa, as proteínas foram precipitadas com acetona e sulfato de amônio, dialisadas, liofilizadas e purificadas por cromatografia de filtração e troca iônica. A quantificação proteica foi realizada pelo método de Bradford e o perfil eletroforético obtido por SDS-PAGE. Para testar a atividade biológica das lectinas foram utilizados ensaios de hemaglutinação bem como de aglutinação das linhagens bacterianas. Em nossos resultados, o método de precipitação proteica por acetona resultou em maior extração quando comparado ao método por sulfato de amônio. A lectina de C. spectabilis R. apresentou um peso molecular de 30 kDa e os ensaios de hemaglutinação foram positivos para a proteína. Assim, concluimos que nas sementes de C. spectabilis R. existem lectinas com capacidade de reconhecer receptores presentes na membrana de eritrócitos humanos e promover aglutinação celular. Por fim, as lectinas da planta C. spectabilis R. também foram capazes de aglutinar L. interrogans e L. biflexa, sendo esta reposta mais acentuada na linhagem patogênica.<br>Lectins are proteins that bind carbohydrate residues with affinity and are involved in the process of cell recognition and signaling in different metabolic pathways. The aim of this study was to isolate, purify and investigate the biological activity of the Crotalaria spectabilis R. lectins in terms of hemagglutination and agglutination capacity of the bacterial strains: Leptospira biflexa and L. interrogans. For protein extraction, the seeds were milled and their cells lysed in 0,15 M NaCl solution. After this step, the proteins were precipitated with acetone and ammonium sulfate, dialyzed, lyophilized and purified by filtration chromatography and ion exchange, respectively. Protein quantification was performed by the Bradford method and the electrophoretic profile by SDS-PAGE. For testing the biological activities of lectins, hemagglutination assays were used as well agglutination of the bacterial strains. In our results, protein precipitation method by acetone resulted in higher yield when compared to ammonium sulfate. The C. spectabilis R. lectin presented a molecular weight of 30 kDa and the hemagglutination assays were positives for the protein. Thus, we conclude that in the C. spectabilis R. seeds there are lectins with capacity to recognize receptors present in the human erythrocytes membrane and to promote cell agglutination. At last, the seed lectin C. spectabilis R. was also able to agglutinate L. interrogans and L. biflexa, this response being stronger in the pathogenic strain.
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Bibi, Rashda. "Synthèse de nouveaux dérivés osidiques pour le ciblage de lectines originales." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2012. http://www.theses.fr/2012ENCM0002.
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Les lectines spécifiques du rhamnose ont été découvertes comme nouvelle classe de lectines dans les années 1990. La plupart de ces lectines a été isolée à partir d'animaux aquatiques. Des récepteurs spécifiques du rhamnose sur les kératinocytes ont été découverts en 1991 quand les reconnaissances entre des glycoprotéines synthétiques incorporées dans des liposomes et des kératinocytes ont été étudiées. Nous avons synthétisé des nouveaux dérivés de rhamnose à cibler ces lectines<br>Rhamnose binding lectines were discovered as new class of lectines in 1990's. Most of these lectines has been isolated from aquatic animals. It was discovered in 1991 that rhamnose specific receptors may be present in human skin while studying the interaction between liposomes incorating synthesitic glycoproteins and keratinocytes. We have synthesized new derivatives of rhamnose to target these lectines
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Santos, Adriano dos [UNESP]. "Estudo da afinidade das proteínas rTgMIC1 e rTgMIC4 da Toxoplasma gondii com fetuína e asialofetuína utilizando técnica piezelétrica." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/92055.
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santos_a_me_araiq.pdf: 1458862 bytes, checksum: f7fe58d688854cba187d0f1e30f22ce7 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>As proteínas de micronema TgMIC1 e TgMIC4 (TgMICs) da Toxoplasma gondii fazem parte de um complexo proteico localizado na superfície do parasita responsável pelo processo de adesão e invasão celular. Os objetivos desse trabalho foram estudar dispositivos piezelétricos contendo em cada um, uma das MICs recombinantes (rTgMIC1 ou rTgMIC4) e utilizá‐los na determinação das constantes de afinidade entre elas com a fetuína e asialofetuína, empregando o modelo da Isoterma de Langmuir. Os dispositivos foram desenvolvidos por meio a abordagem de monocamadas automontadas (SAM) mista de tióis, utilizando solução etanólica contendo 2,5 mM de ácido 11‐mercaptoundecanóico (11‐MUA) e 7,5 mM de 6‐mercapto‐1‐hexanol (C6OH). A formação da SAM, realizada em temperatura ambiente por 12 h, foi monitorada pela técnica de Microbalança a Cristal de Quartzo com Fator Dissipativo (QCM‐D) e voltametria cíclica utilizando o par redox [FeII(CN)6]4‐/ FeIII(CN)6]3‐. Os resultados obtidos por ambas as técnicas evidenciaram a formação de SAM rígida e de elevado grau de cobertura superficial após cinética lenta em que processos de adsorção e organização dos tióis ocorreram simultaneamente. Para a imobilização das rTgMICs, solução aquosa contendo 10 mM de EDC (N‐etil‐N‐(dimetilaminopropil) carbodiimida) e 20 mM de NHS (N‐hidroxisuccinimida) foi utilizada para a ativação dos grupos carboxílicos presentes na SAM por 2 h, e o processo acompanhado por QCM‐D apresentou resultados compatíveis com aqueles encontrados na literatura. Pela mesma técnica, foi possível verificar que ambas as rTgMICs se imobilizam sobre o cristal de quartzo após sua incubação com solução 0,15 mg/mL de cada rTgMIC em tampão Tris‐HCl contendo 200 mM de NaCl...<br>The Toxoplasma gondii micronemal proteins TgMIC1 and TgMIC4 (TgMICs) are part of a protein complex located on the surface of the parasite responsible for the process of cellular adhesion and invasion. The goal of the present work was to study a piezoelectric device containing the recombinant MICs (rTgMIC1 or rTgMIC4) and use it in determining the affinity constants between the MICs with fetuin and asialofetuin, employing the Langmuir isotherm model. The devices were developed using the approach of self‐assembled monolayer (SAM) in ethanolic solution containing 2.5 mM of 11‐mercaptoundecanoic acid (11‐MUA) and 7.5 mM of 6‐mercaptohexanol (C6OH). The SAM formation, held at room temperature for 12 h, was monitored by the Quartz Crystal Microbalance technique with Dissipative Factor (QCM‐D) and cyclic voltammetry using the redox couple [FeII(CN)6]4‐/FeIII(CN) 6]3‐. The results obtained from both techniques showed the formation of a rigid and high surface degree coverage SAM after a slow kinetic process in which adsorption and organization of the thiols occur simultaneously. For the immobilization of rTgMICs, aqueous solution containing 10 mM EDC N‐ethyl‐N‐(dimethylaminopropyl) carbodiimide and 20 mM NHS (N‐hydroxysuccinimide) was used for 2 h, and the process followed by QCM‐D was consistent with those found in the literature. By the same technique it was found that both rTgMICs are immobilized on the quartz crystal after incubation whit solution 0.15 mg/mL of each rTgMIC in Tris‐HCl containing 200 mM NaCl (pH 8.0) for 2 h. Unlike the functionalization of the quartz crystal rTgMIC4, remaining adsorption sites were observed in the process using the rTgMIC1, wherein the blocking step using 0.1% gelatin solution for 2 h was required. Throughout the QCM‐D technique it was possible... (Complete abstract click electronic access below)
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Santos, Adriano dos. "Estudo da afinidade das proteínas "rTgMIC1" e "rTgMIC4" da Toxoplasma gondii com fetuína e asialofetuína utilizando técnica piezelétrica /." Araraquara : [s.n.], 2012. http://hdl.handle.net/11449/92055.
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Orientador: Paulo Roberto Bueno<br>Banca: Emanuel Carrilho<br>Banca: Maria Cristina Roque Antunes Barreira<br>Resumo: As proteínas de micronema TgMIC1 e TgMIC4 (TgMICs) da Toxoplasma gondii fazem parte de um complexo proteico localizado na superfície do parasita responsável pelo processo de adesão e invasão celular. Os objetivos desse trabalho foram estudar dispositivos piezelétricos contendo em cada um, uma das MICs recombinantes (rTgMIC1 ou rTgMIC4) e utilizá‐los na determinação das constantes de afinidade entre elas com a fetuína e asialofetuína, empregando o modelo da Isoterma de Langmuir. Os dispositivos foram desenvolvidos por meio a abordagem de monocamadas automontadas (SAM) mista de tióis, utilizando solução etanólica contendo 2,5 mM de ácido 11‐mercaptoundecanóico (11‐MUA) e 7,5 mM de 6‐mercapto‐1‐hexanol (C6OH). A formação da SAM, realizada em temperatura ambiente por 12 h, foi monitorada pela técnica de Microbalança a Cristal de Quartzo com Fator Dissipativo (QCM‐D) e voltametria cíclica utilizando o par redox [FeII(CN)6]4‐/ FeIII(CN)6]3‐. Os resultados obtidos por ambas as técnicas evidenciaram a formação de SAM rígida e de elevado grau de cobertura superficial após cinética lenta em que processos de adsorção e organização dos tióis ocorreram simultaneamente. Para a imobilização das rTgMICs, solução aquosa contendo 10 mM de EDC (N‐etil‐N‐(dimetilaminopropil) carbodiimida) e 20 mM de NHS (N‐hidroxisuccinimida) foi utilizada para a ativação dos grupos carboxílicos presentes na SAM por 2 h, e o processo acompanhado por QCM‐D apresentou resultados compatíveis com aqueles encontrados na literatura. Pela mesma técnica, foi possível verificar que ambas as rTgMICs se imobilizam sobre o cristal de quartzo após sua incubação com solução 0,15 mg/mL de cada rTgMIC em tampão Tris‐HCl contendo 200 mM de NaCl... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: The Toxoplasma gondii micronemal proteins TgMIC1 and TgMIC4 (TgMICs) are part of a protein complex located on the surface of the parasite responsible for the process of cellular adhesion and invasion. The goal of the present work was to study a piezoelectric device containing the recombinant MICs (rTgMIC1 or rTgMIC4) and use it in determining the affinity constants between the MICs with fetuin and asialofetuin, employing the Langmuir isotherm model. The devices were developed using the approach of self‐assembled monolayer (SAM) in ethanolic solution containing 2.5 mM of 11‐mercaptoundecanoic acid (11‐MUA) and 7.5 mM of 6‐mercaptohexanol (C6OH). The SAM formation, held at room temperature for 12 h, was monitored by the Quartz Crystal Microbalance technique with Dissipative Factor (QCM‐D) and cyclic voltammetry using the redox couple [FeII(CN)6]4‐/FeIII(CN) 6]3‐. The results obtained from both techniques showed the formation of a rigid and high surface degree coverage SAM after a slow kinetic process in which adsorption and organization of the thiols occur simultaneously. For the immobilization of rTgMICs, aqueous solution containing 10 mM EDC N‐ethyl‐N‐(dimethylaminopropyl) carbodiimide and 20 mM NHS (N‐hydroxysuccinimide) was used for 2 h, and the process followed by QCM‐D was consistent with those found in the literature. By the same technique it was found that both rTgMICs are immobilized on the quartz crystal after incubation whit solution 0.15 mg/mL of each rTgMIC in Tris‐HCl containing 200 mM NaCl (pH 8.0) for 2 h. Unlike the functionalization of the quartz crystal rTgMIC4, remaining adsorption sites were observed in the process using the rTgMIC1, wherein the blocking step using 0.1% gelatin solution for 2 h was required. Throughout the QCM‐D technique it was possible... (Complete abstract click electronic access below)<br>Mestre
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Destecroix, Harry. "Anthracene based synthetic lectins." Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.682557.
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Over the past 40 years there has been substantial interest in continuous glucose monitors (CGMs) for diabetes management. Much of the work has focused on the use of enzymes, lectins (carbohydrate binding proteins) or boronic acids as the sensing element, but instability and biocompatibility has hindered development. This has presented an 0pp0l1unity for supramolecular chemists to make synthetic lectins for glucose that respond in real time to glucose in the blood. However, carbohydrate recognition in water presents a challenge due to the hydromimetic nature of the substrate. Moreover, subtle structural differences between monosaccharides makes selectivity problematic. Despite these difficulties, our group has met with some success in designing synthetic lectins over the past decade. Recently we reported a simple monocyclic receptor An-L 34 for glucose which is accessible in only 5 steps with 23% overall yield. The receptor binds glucose with excellent selectivity over physiological blood glucose levels, displaying increases in fluorescence emission suggesting its potential as a CGM. We report the development of a series of receptors based on the new architecture. New synthetic procedures have provided access to asymmetrical systems that have highlighted the driving forces behind binding. 2nd and 3rd generation dendritic solubilising groups have been synthesised leading to receptors that are less prone to aggregation and with enhanced affinity for glucose and improved optical properties for sensing. The improvements are attributed to the interaction of the carboxylate groups with the sugar from the larger solubilising groups. Using this approach a new receptor with 100 fold selectivity for positively charged monosaccharide glucosamine has been demonstrated. The new generation systems have been screened in human blood plasma, with the 2nd generation systems showing enhancements in response to glucose. Furthermore work has started towards immobilisation of receptors for fibre optic sensing.
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Andersson, Pontus. "Comparison of Lectins and their suitability in Lectin Affinity Chromatography for isolation of Glycoproteins." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-417024.
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Virtually all extracellular proteins in humans are glycoproteins and likewise are many biopharmaceuticals. The glycosylation is directly correlated to biological function and stability of these proteins. The ability to isolate glycoproteins is thus of great importance in many applications. The most common isolation method for glycoproteins is affinity chromatography using lectins, a ubiquitous and versatile group of carbohydrate-binding proteins. The lectin Concanavalin A (ConA) has long been used for this purpose but suffers from undesired leakage into the eluate, causing an inquiry of alternative chromatography ligands or optimization of the ConA resin.In this study, a total of 20 different lectins, including ConA, were evaluated and compared in terms of suitability as ligands in affinity chromatography for glycoprotein isolation. The lectins’ binding to glycoproteins were studied, mainly through microtiter plate binding assays using a monoclonal IgG1 antibody and Conalbumin (Ovotransferrin). Further, sugar-specificities and potential eluting sugars for the lectins were examined through inhibition with eight different carbohydrates. Additionally, the glycoprotein binding and leakage of ConA columns were examined, and a potential leakagereducing treatment of ConA resin evaluated.ConA was found to be superior in binding to the investigated glycoproteins but exhibited a limited binding when immobilized to an agarose resin. This discrepancy is likely a consequence of structurally hidden glycans on the used glycoproteins and requirements of long residence time when used in a chromatographic setting. Binding competition with several sugars were investigated with a similar microtiter plate binding assay. This method displayed potential to predict the behaviour of sugars and their suitability as eluting agents in a chromatography column. The best eluting sugar for ConA was showed to be methylmannoside, ideally in combination with methylglucoside. Lastly, evaluation of ConA columns with a crosslinking glutaraldehyde-treatment showed that the ConA ligand leakage may be significantly reduced, although further studies and optimizations are needed.This study thus presents a repertoire of lectins and their differences in terms of glycoprotein-binding and sugar-specificity, as well as evaluations of ConA columns’ efficiency and potential leakage-prevention.
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Sousa, Bruno Lopes de. "CaracterizaÃÃo estrutural das formas silvestre e recombinante de uma lectina de sementes de Vatairea macrocarpa Benth e anÃlise das suas bases moleculares de ligaÃÃo ao antÃgeno Tn." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13196.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico<br>As lectinas consitem em uma classe diversificada de proteÃnas, capazes de reconhecer estruturas glicÃdicas de forma reversÃvel e com alta especificidade, no entanto sem alterar suas estruturas quÃmicas, participando de vÃrios processos celulares importantes. Dentre as diferentes famÃlias de lectinas, as isoladas a partir de leguminosas sÃo as mais extensivamente estudadas, havendo sido relatada a influÃncias dessas molÃculas sobre diversos processos patolÃgicos, incluindo a carcinogÃnese. NotÃveis propriedades antitumorais tÃm sido detectadas para algumas lectinas de leguminosas, resultantes da sua habilidade em induzir a morte celular ou a autofagia em cÃlulas cancerÃgenas, o que atraÃdo atenÃÃo para suas possiveis aplicaÃÃes biomÃdicas. AlÃm disso, algumas lectinas desse grupo especificas para galactose/N-acetil-D-galactosamina (Gal/GalNAc) tÃm se mostrado Ãteis como marcadores histoquÃmicos na pesquisa do cÃncer e a caracterizaÃÃo estrutural dessas lectinas em complexo com diferentes epÃtopos cancerÃgenos vem sendo realizada com sucesso. A lectina isolada a partir das sementes da leguminosa Vatairea macrocarpa (VML) à uma lectina bem caracterizada especÃfica para Gal/GalNAc capaz de reconhecer especificamente o antÃgeno Tn (GalNAc-α-O-Ser), naturalmente encontrado em O-mucinas presentes em diferentes tipos de cÃncer. As estruturas cristalogrÃficas para a VML em complexo com o antÃgeno Tn e GalNAc foram determinadas com resoluÃÃes de 1.4 e 1.7 Ã, respectivamente. A maioria das lectinas obtidas a partir de fontes naturais consiste em misturas de diferentes isoformas, uma caracterÃstica indesejada para aplicaÃÃes biomÃdicas. Com base nisso, uma construÃÃo recombinante para VML (rVML) foi expressa em Escherichia coli, sendo obtida de forma solÃvel em com alto rendimento. A estrutura cristalina para a rVML, bem como para seus complexos com o antÃgeno Tn, GalNAc e α-Lactose foram determinadas com resoluÃÃes de 1.7, 2.7, 2 e 1.8 Ã, respectivamente, apresentando a mesma estrutura geral e padrÃes de interaÃÃo que a lectina silvestre. Com o intuito de gerar um perfil comparativo entre a VML e outras lectinas de leguminosas capazes de reconhecer o antÃgeno Tn, foram realizadas anÃlises de docking molecular utilizando fragmentos de O-mucinas diferentemente decorados com o antÃgeno Tn. Esse perfil ressalta como alteraÃÃes sutis no elenco ou disposiÃÃo dos aminoÃcidos constituintes do sÃtio de ligaÃÃo a carboidrato, que talvez nÃo influenciem a capacidade de ligaÃÃo a monossacarÃdeo, podem impactar diretamente a habilidade dessas lectinas em reconhecer antÃgenos em condiÃÃes naturais. Adicionalmente aos jà caracterizados efeitos biolÃgicos relatados para VML, a similaridade entre sua estrutura e perfis de interaÃÃes quando comparadas a outras lectinas comumente utilizadas como marcadores histoquÃmicos (e.g., VVLB4 e SBA), sugerem fortemente a possÃvel utilizaÃÃo da VML como uma nova ferramenta na pesquisa do cÃncer. Esse trabalho consiste no primeiro relato de estruturas cristalogrÃficas para uma lectina de leguminosa especÃfica para Gal/GalNAc da tribo Dalbergieae.<br>Lectins are a very diverse class of proteins able to bind specific sugar structures reversibly and with high specificity, but without enzymatically modifying them, triggering several important cellular processes. Among the different lectin families, legume lectins are the most thoroughly studied and have been widely reported to exhibit a number of links to many pathological processes, including carcinogenesis. The remarkable anti-tumor properties of some legume lectins, resulting from their ability to induce programmed cell death and/or autophagocytosis in cancer cells have attracted much attention for biomedical applications. Moreover, a few galactose/N-acetylgalactosamine (Gal/GalNAc)-binding lectins from this group have proven to be useful markers for cancer histochemistry, and the structural characterization of these lectins bound to specific cancer epitopes has been carried out successfully. The seed lectin isolated from the legume tree Vatairea macrocarpa (VML) is a well characterized Gal/GalNAc-binding protein able to specifically recognize naturally occurring O-mucins presenting the carcinoma epitope Tn antigen (GalNAc-α-O-Ser). The crystal structures of VML in complex with Tn antigen and GalNAc have been determined at the resolution of 1.4 and 1.7 Ã, respectively. Unfortunately, most of lectins obtained from natural sources consist in a mixture of forms, which is an undesired feature for biomedical applications. Thus, the recombinant form of VML (rVML) was expressed in Escherichia coli, being obtained soluble and wih high yielding. The crystal structure for rVML, as well as for the complex with Tn antigen, GalNAc and α-Lactose have been determined at resolutions of 1.7, 2.7, 2 and 1.8 Ã, respectively, presenting the same overall structure and binding patterns as the wild lectin. Molecular docking analysis of this new structure and other Tn-binding legume lectins to O-mucin fragments differently decorated with this antigen provides a comparative binding profile among these proteins, stressing that subtle alterations that may not influence monosaccharide binding can, nonetheless, directly impact the ability of these lectins to recognize naturally occurring antigens. In addition to the specific biological effects of VML, the structural and binding similarities between it and other lectins commonly used as histological markers (e.g., VVLB4 and SBA) strongly suggest that VML can be used as a new tool for cancer research. This is the first report of crystal structures of a Gal/GalNAc-binding legume lectin from the Dalbergieae tribe.
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Howgego, Joshua David. "Synthetic lectins with novel selectivity." Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.573385.
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Carbohydrates are the most plentiful organic molecules on the surface of the earth and also some of the most complex. They are not just fuel sources, but also function as identifying markers for cells, on the surfaces of which they reside in the form of glycoconjugates. These identifying molecules are recognised by lectins; proteins which bind carbohydrates through non-covalent interactions. This recognition mediates a whole range of important biological processes, from fertilisation to infection with pathogens. 'Synthetic lectins' in the context of this thesis are artificially designed and synthesised organic receptor molecules. They bind sugars in aqueous environments through non-covalent interactions and as such may be considered biomimetic in the strictest sense. Synthetic lectins designed according to the 'temple' principles developed in the Davis group have so far been successful in binding sugars which have all their hydroxyl groups orientated equatorially, such as glucose. In this thesis the problem of how to design synthetic lectins for monosaccharides with less uniform distribution of functionality (for example mannose or galactose) is explored. To that end the synthesis of receptors 1 - 3 is described. Characterisation of the binding behaviour of these molecules reveals new patterns of selectivity; for example, disaccharides are bound in preference to monosaccharides. Receptor 4 shows a small but significant affinity for N-acetylneuraminic acid. This substrate is of widespread importance in physiological signalling, and few artificial receptors have previously bound this substrate in water through purely non-covalent interactions.
Libros sobre el tema "Lectins"
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Elumalai, Preetham, and Sreeja Lakshmi, eds. Lectins. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-7462-4.
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Hirabayashi, Jun, ed. Lectins. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-1292-6.
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Sharon, N., and H. Lis. Lectins. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7.
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Sharon, Nathan, and Halina Lis. Lectins. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6953-6.
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1923-, Lis H., ed. Lectins. 2nd ed. Dordrecht: Kluwer Academic Publishers, 2003.
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Elumalai, Preetham, Baskaralingam Vaseeharan, and Sreeja Lakshmi, eds. Aquatic Lectins. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-0432-5.
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Kenneth, Olden, and Parent James Brian, eds. Vertebrate lectins. New York: Van Nostrand Reinhold, 1987.
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1938-, Mirelman David, ed. Microbial lectins and agglutinins: Properties and biological activity. New York: Wiley, 1986.
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Gabius, Hans Joachim, and Sigrun Gabius, eds. Lectins and Cancer. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-76739-5.
Texto completoCapítulos de libros sobre el tema "Lectins"
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Sharon, N., and H. Lis. "Introduction." In Lectins, 1–5. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7_1.
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Sharon, N., and H. Lis. "Lectin resistant cells." In Lectins, 92–96. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7_10.
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Sharon, N., and H. Lis. "Functions in nature." In Lectins, 97–107. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7_11.
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Sharon, N., and H. Lis. "Epilogue." In Lectins, 108. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7_12.
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Sharon, N., and H. Lis. "History." In Lectins, 6–19. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7_2.
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Sharon, N., and H. Lis. "Occurrence and isolation." In Lectins, 20–25. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7_3.
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Sharon, N., and H. Lis. "Biological activities." In Lectins, 26–36. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7_4.
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Sharon, N., and H. Lis. "Carbohydrate specificity." In Lectins, 37–46. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7_5.
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Sharon, N., and H. Lis. "Molecular properties." In Lectins, 47–58. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7_6.
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Sharon, N., and H. Lis. "Three dimensional structures." In Lectins, 59–64. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-011-4846-7_7.
Texto completoActas de conferencias sobre el tema "Lectins"
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Goyal, Ayushi, Razia Sultana, Sarosh Saeed, Piyush Bhati, Varsha Kumawat, Rishabh Kumar, Neetu, et al. "Leveraging Antiviral Lectins for Developing Glycan-Based Vaccines by Employing Standard and AI-Driven Approaches." In 2025 International Conference on Cognitive Computing in Engineering, Communications, Sciences and Biomedical Health Informatics (IC3ECSBHI), 1533–38. IEEE, 2025. https://doi.org/10.1109/ic3ecsbhi63591.2025.10990882.
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Scheefers, H., A. Kobus, and R. Geyer. "CARBOHYDRATE COMPOSITION AND LECTIN BINDING AFFINITIES OF HUMAN PLACENTAL TISSUE FACTOR." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643737.
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Tissue factor (TF) is a widely distibuted membrane glycoprotein and the most potent trigger of bloodcoagulation. It serves as an essential cofactor for the activation of Factor IX and X by Factor Vll/VIIa.TF is a lipoprotein composed of a phospholipid portion and a glycosylated apoprotein (apo-TF). The procoagulant activity of bovine brain TF is inhibited bythe lectin Con A indicating that the carbohydrates of TF might play a functional role in its interactionwith Factor Vll/VIIa.In the present study apo-TF was purified from human placenta by repeated SDS-PAGE to a purity of 95%. The carbohydrates of apo-TF wereanalyzed by capillary gas- liquid-chromatography andmass-fragmentography. This analysis revealed that apo-TF contains about 16% (w/w) carbohydrate consistingof 50.4 mole% N-acetylglucosamine, 22.2 mole% mannose, 21.0 mole% galactose, 3.2 mole% fucose and 3.2 mole% N-acetylgalactosamine. Further information on the structure of the carbohydrate moieties of the apoTF was achieved by determining the binding affinities of the apo-TF to ten different lectins. For this purpose a semiquantitative spot lectino sorbent assaywas developed. This assay is based on the detection of peroxidase-labeled lectins after being bound to the carbohydrate moieties of apo-TF adsorbed onto a nitrocellulose membrane. Human placental apo-TF showed the strongest affinity to wheat germ agglutinin which specifically binds to N-acetylglucosamine and sialic acid residues.In contrast to bovine brain apo-TF, human placental apo-TF only weakly interacted with Con A, which is known to recognize mannosyl residues in mannose-rich, hybrid- and biantennary glycans,but not in tri- or tetraantennary oligosaccharides of the complex type. From the carbohydrate constituent analysis and from the lectin binding studies it can be concluded that human placental apo-TF carriesabout four N-linked higher branched oligosaccharide chains.
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Murarasu, Thomas, and Ludger Johannes. "Abstract 5772: Engineered lectins to treat cancer." In Proceedings: AACR Annual Meeting 2018; April 14-18, 2018; Chicago, IL. American Association for Cancer Research, 2018. http://dx.doi.org/10.1158/1538-7445.am2018-5772.
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Petrova, N. V., O. V. Gorshkov, A. R. Nazipova, and T. A. Gorshkova. "Differential expression of Nictaba lectins in flax plants." In IX Congress of society physiologists of plants of Russia "Plant physiology is the basis for creating plants of the future". Kazan University Press, 2019. http://dx.doi.org/10.26907/978-5-00130-204-9-2019-346.
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Alen’kina, S. A., and V. E. Nikitina. "Influence of Azospirillum lectins on a stress-dependent change in the content of low-molecular antioxidants in plants." In 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.019.
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It was shown that the lectins Azospirillum brasilense Sp7 (epiphyte) and Sp245 (endophyte) with different efficacy changed the content of ascorbate and glutathione in the initial period of exposure to CuSO4, CoSO4, ZnSO4, Pb(CH3COO)2 on the wheat seedling roots.
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Krull, U. J., R. S. Brown, E. T. Vandenberg, and B. D. Hougham. "Optical biosensors from chemical transduction by lectins and neural receptors." In Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 1988. http://dx.doi.org/10.1109/iembs.1988.95045.
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O'Connell, Kathleen M., Erin E. Gatrone, Anna A. Veldkamp, and John J. Lavigne. "Abstract 2013: SYNTHETIC LECTINS FOR THE DETERMINATION OF BREAST CANCER SUBTYPE." In Proceedings: AACR 106th Annual Meeting 2015; April 18-22, 2015; Philadelphia, PA. American Association for Cancer Research, 2015. http://dx.doi.org/10.1158/1538-7445.am2015-2013.
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Coêlho Bernardo, Lucas, and Nathalia Regina Galvão Silva. "An alternative for healing through the use of lectins: an overview." In MOL2NET 2018, International Conference on Multidisciplinary Sciences, 4th edition. Basel, Switzerland: MDPI, 2018. http://dx.doi.org/10.3390/mol2net-04-05516.
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Ma, Di, Yanjuan Li, and Dong Chen. "Predlectins-MLP: an improved predictor of cancer-lectins using mixed features." In ICBBT 2024: 2024 16th International Conference on Bioinformatics and Biomedical Technology, 96–101. New York, NY, USA: ACM, 2024. http://dx.doi.org/10.1145/3674658.3674675.
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Lakhtin, M., V. Lakhtin, S. Andina, S. Afanasiev, and V. Aleshkin. "343 Complement lectin system cofunctions to other protective pro-tein systems involving relationships between lectins and glycoconjugates against autoimmune and infectious diseases." In LUPUS 2017 & ACA 2017, (12th International Congress on SLE &, 7th Asian Congress on Autoimmunity). Lupus Foundation of America, 2017. http://dx.doi.org/10.1136/lupus-2017-000215.343.
Texto completoInformes sobre el tema "Lectins"
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Thompson, Paul R., and John J. Lavigne. Synthetic Lectins: New Tools for Detection and Management of Prostate Cancer. Fort Belvoir, VA: Defense Technical Information Center, August 2014. http://dx.doi.org/10.21236/ada612862.
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Lavigne, John J. Synthetic Lectins: New Tools for Detection and Management of Prostate Cancer. Fort Belvoir, VA: Defense Technical Information Center, August 2013. http://dx.doi.org/10.21236/ada591012.
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Sharon, Nathan, and Maarten Chrispeels. Improvement of the Nutritional Value of Legume Storage Proteins by Genetic Engineering: Studies with Legume Lectins. United States Department of Agriculture, October 1991. http://dx.doi.org/10.32747/1991.7604278.bard.
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Baliarsingh, Snigdha, and Bharat Bhusan Patnaik. Identification of Novel Lectins from Freshwater Prawn, Macrobrachium rosenbergii, and Expression Analysis in Response to Vibrio harveyi and M. rosenbergii nodavirus. Peeref, July 2022. http://dx.doi.org/10.54985/peeref.2207p9700127.
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Fluhr, Robert, and Maor Bar-Peled. Novel Lectin Controls Wound-responses in Arabidopsis. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7697123.bard.
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Innate immune responses in animals and plants involve receptors that recognize microbe-associated molecules. In plants, one set of this defense system is characterized by large families of TIR–nucleotide binding site–leucine-rich repeat (TIR-NBS-LRR) resistance genes. The direct interaction between plant proteins harboring the TIR domain with proteins that transmit and facilitate a signaling pathway has yet to be shown. The Arabidopsis genome encodes TIR-domain containing genes that lack NBS and LRR whose functions are unknown. Here we investigated the functional role of such protein, TLW1 (TIR LECTIN WOUNDRESPONSIVE1). The TLW1 gene encodes a protein with two domains: a TIR domain linked to a lectin-containing domain. Our specific aim in this proposal was to examine the ramifications of the TL1-glycan interaction by; A) The functional characterization of TL1 activity in the context of plant wound response and B) Examine the hypothesis that wounding induced specific polysaccharides and examine them as candidates for TL-1 interactive glycan compounds. The Weizmann group showed TLW1 transcripts are rapidly induced by wounding in a JA-independent pathway and T-DNA-tagged tlw1 mutants that lack TLW1 transcripts, fail to initiate the full systemic wound response. Transcriptome methodology analysis was set up and transcriptome analyses indicates a two-fold reduced level of JA-responsive but not JA-independent transcripts. The TIR domain of TLW1 was found to interact directly with the KAT2/PED1 gene product responsible for the final b-oxidation steps in peroxisomal-basedJA biosynthesis. To identify potential binding target(s) of TL1 in plant wound response, the CCRC group first expressed recombinant TL1 in bacterial cells and optimized conditions for the protein expression. TL1 was most highly expressed in ArcticExpress cell line. Different types of extraction buffers and extraction methods were used to prepare plant extracts for TL1 binding assay. Optimized condition for glycan labeling was determined, and 2-aminobenzamide was used to label plant extracts. Sensitivity of MALDI and LC-MS using standard glycans. THAP (2,4,6- Trihydroxyacetophenone) showed minimal background peaks at positive mode of MALDI, however, it was insensitive with a minimum detection level of 100 ng. Using LC-MS, sensitivity was highly increased enough to detect 30 pmol concentration. However, patterns of total glycans displayed no significant difference between different extraction conditions when samples were separated with Dionex ICS-2000 ion chromatography system. Transgenic plants over-expressing lectin domains were generated to obtain active lectin domain in plant cells. Insertion of the overexpression construct into the plant genome was confirmed by antibiotic selection and genomic DNA PCR. However, RT-PCR analysis was not able to detect increased level of the transcripts. Binding ability of azelaic acid to recombinant TL1. Azelaic acid was detected in GST-TL1 elution fraction, however, DHB matrix has the same mass in background signals, which needs to be further tested on other matrices. The major findings showed the importance of TLW1 in regulating wound response. The findings demonstrate completely novel and unexpected TIR domain interactions and reveal a control nexus and mechanism that contributes to the propagation of wound responses in Arabidopsis. The implications are to our understanding of the function of TIR domains and to the notion that early molecular events occur systemically within minutes of a plant sustaining a wound. A WEB site (http://genome.weizmann.ac.il/hormonometer/) was set up that enables scientists to interact with a collated plant hormone database.
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Spiegel, Yitzhak, Michael McClure, Itzhak Kahane, and B. M. Zuckerman. Characterization of the Phytophagous Nematode Surface Coat to Provide New Strategies for Biocontrol. United States Department of Agriculture, November 1995. http://dx.doi.org/10.32747/1995.7613015.bard.
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Chemical composition and biological role of the surface coat (SC) of the root-knot nematodes, Meloidogyne spp. are described. SC proteins of M. incognita race 3 infective juveniles (J2) were characterized by electrophoresis and western blotting of extracts from radioiodine and biotin-labelled nematodes. J2 labelled with radioiodine and biotin released 125I and biotin-labelled molecules into water after 20 hours incubation, indicating that SC proteins may be loosely attached to the nematode. Antiserum to the principal protein reacted with the surface of live J2 and with surface proteins previously separated by electrophoresis. Human red blood cells (HRBC) adhered to J2 of several tylenchid nematodes over the entire nematode body. HRBC adhered also to nylon fibers coated with SC extracted from M. javanica J2; binding was Ca++/Mg++ dependent, and decreased when the nylon fibers were coated with bovine serum albumin, or pre-incubated with fucose and mannose. These experiments support a working hypothesis that RBC adhesion involves carbohydrate moieties of HRBC and carbohydrate-recognition domain(s) (CRD) distributed on the nematode surface. To our knowledge, this is the first report of a surface CRD i the phylum Nematoda. Gold-conjugated lectins and neoglycoproteins combined with silver enhancement have been used for the detection of carbohydrates and CRD, respectively, on the SC of M. javanica J2. Biotin reagents were used to trace surface proteins, specifically, on live J2. The labile and transitory nature of the SC was demonstrated by the dynamics of HRBC adherence to detergent-treated J2, J2 at different ages or fresh-hatched J2 held at various temperatures. SC recovery was demonstrated also by a SDS-PAGE profile. Monoclonal antibodies developed to a cuticular protein of M. incognita J2 gave a slight, but significant reduction in attachment of Pasteuria penetrans spores. Spore attachment as affected by several enzymes was inconsistent: alcian blue, which specifically blocks sulfyl groups, had no afffect on spore attachment. Treatment with cationized ferritin alone or catonized ferritin following monoclonal antibody caused significant decreases in spore attachment. Those results suggest a role in attachment by negatively charged groups.
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Kraybill, William H. Lectin Enzyme Assay Detection of Viruses, Tissue Culture, and a Mycotoxin Simulant. Fort Belvoir, VA: Defense Technical Information Center, September 1988. http://dx.doi.org/10.21236/ada276469.
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Braunschweig, Adam B., Shudan Bian, and Han Xu. Carbohydrate Nanotechnology: Hierarchical Assemblies and Information Processing from Oligosaccharide-Synthetic Lectin Host-Guest. Fort Belvoir, VA: Defense Technical Information Center, September 2014. http://dx.doi.org/10.21236/ada612784.
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Wang, Xin. Synthesis and Characterization of Glyconanomaterials, and Their Applications in Studying Carbohydrate-Lectin Interactions. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.626.
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Deutscher, Susan. Radiolabeled Peptide Scaffolds for PET/SPECT - Optical in Vivo Imaging of Carbohydrate-Lectin Interactions. Office of Scientific and Technical Information (OSTI), September 2014. http://dx.doi.org/10.2172/1158790.
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