scholarly journals Glycan-decorated HPMA copolymers as high-affinity lectin ligands

2017 ◽  
Vol 8 (17) ◽  
pp. 2647-2658 ◽  
Author(s):  
P. Bojarová ◽  
P. Chytil ◽  
B. Mikulová ◽  
L. Bumba ◽  
R. Konefał ◽  
...  
Keyword(s):  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Binding Affinities ◽  
High Affinity ◽  
Hpma Copolymers ◽  
Hydroxypropyl Methacrylamide

New conjugates of N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers tethered with chitooligosaccharidic epitopes of varying lengths are potent ligands of wheat germ agglutinin, reaching subnanomolar binding affinities.

Immobilized wheat germ agglutinin separates small oligosaccharides derived from poly-N-acetyllactosaminoglycans of embryonal carcinoma cells

1988 ◽  
Vol 66 (5) ◽  
pp. 449-453 ◽  
Author(s):  
Ossi Renkonen ◽  
Pekka Mäkinen ◽  
Karl Hård ◽  
Jari Helin ◽  
Leena Penttilä
Keyword(s):  
Chromatographic Separation ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Embryonal Carcinoma ◽  
Carcinoma Cells ◽  
Binding Affinities ◽  
Embryonal Carcinoma Cells ◽  
Small Column ◽  
Teratocarcinoma Cells ◽  
Weak Binding

Five pure oligosaccharides derived from poly-N-acetyllactosaminoglycans of teratocarcinoma cells were chromatographed on immobilized wheat germ agglutinin (WGA). Three of them, Galβ1-4GlcNAc, GlcNAcβ1-3Gal, and GlcNAcβ1-3Galβ1-4GlcNAc, revealed only weak binding, but GlcNAcβ1-6Galβ1-4GlcNAc was bound moderately and GlcNAcβ1-6Gal was bound quite strongly. The differences in the binding affinities were large enough to allow chromatographic separation of the five oligosaccharides into three distinct fractions in a small column of WGA–agarose.

scholarly journals High-affinity multivalent wheat germ agglutinin ligands by one-pot click reaction

2012 ◽  
Vol 8 ◽  
pp. 819-826 ◽  
Author(s):  
Henning S G Beckmann ◽  
Heiko M Möller ◽  
Valentin Wittmann
Keyword(s):  
Molecular Modeling ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Click Reaction ◽  
One Pot ◽  
High Affinity ◽  
Reference Ligand ◽  
Molecular Modeling Studies ◽  
Nanomolar Range

A series of six mono-, di-, and trivalent N,N’-diacetylchitobiose derivatives was conveniently prepared by employing a one-pot procedure for Cu(II)-catalyzed diazo transfer and Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC) starting from commercially available amines. These glycoclusters were probed for their binding potencies to the plant lectin wheat germ agglutinin (WGA) from Triticum vulgaris by an enzyme-linked lectin assay (ELLA) employing covalently immobilized N-acetylglucosamine (GlcNAc) as a reference ligand. IC50 values were in the low micromolar/high nanomolar range, depending on the linker between the two disaccharides. Binding enhancements β up to 1000 for the divalent ligands and 2800 for a trivalent WGA ligand, compared to N,N’-diacetylchitobiose as the corresponding monovalent ligand, were observed. Molecular modeling studies, in which the chitobiose moieties were fitted into crystallographically determined binding sites of WGA, correlate the binding enhancements of the multivalent ligands with their ability to bind to the protein in a chelating mode. The best WGA ligand is a trivalent cluster with an IC50 value of 220 nM. Calculated per mol of contained chitobiose, this is the best WGA ligand known so far.

Failure of 6D1 or Exposure of Platelets to ADP to Affect Agglutination Induced by Wheat Germ Agglutinin

1989 ◽  
Vol 62 (02) ◽  
pp. 815 ◽  
Author(s):  
Marjorie B Zucker ◽  
Robert A Grant ◽  
Evelyn A Mauss
Keyword(s):  
Wheat Germ Agglutinin ◽  
Wheat Germ

Synthesis and Photoproperties of a Substituted Zinc(II) Phthalocyanine-N-(2-hydroxypropyl)methacrylamide Copolymer Conjugate

1993 ◽  
Vol 58 (10) ◽  
pp. 2321-2336 ◽  
Author(s):  
Zhong-wei Gu ◽  
John D. Spikes ◽  
Pavla Kopečková ◽  
Jindřich Kopeček
Keyword(s):  
Organic Solvents ◽  
Water Soluble ◽  
Lower Probability ◽  
Hpma Copolymer ◽  
Polymeric Derivative ◽  
Oxygen Generation ◽  
Hpma Copolymers ◽  
Hydroxypropyl Methacrylamide ◽  
Polymeric Carriers ◽  
Thiol Proteinases

In cancer photodynamic therapy (PDT), improved efficiency of photosensitizer delivery to tumors may be obtained by binding them to targetable water soluble polymeric carriers. However, attachment of photosensitizers to Macromolecular carriers may alter their spectral and photosensitizing properties. In this study, a new monosubstituted phthalocyanine derivative, N-glycyl zinc(II) 4,9,16,23-tetraaminophthalocyanine (G-TAPC-Zn) was synthesized by the reaction of zinc(II) 4,9,16,23-tetraaminophthalocyanine (TAPC-Zn) with N-tert-butoxycarbonyl-glycine N'-hydroxybenzotriazole ester followed by deprotection of the tert-butoxycarbonyl (BOC) group. G-TAPC-Zn contains an aliphatic amino group suitable for attachment to water soluble polymeric carriers. By aminolysis of a polymeric precursor, an N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer containing oligopeptide (GFLG) side-chains terminated in p-nitrophenyl ester groups, with G-TAPC-Zn a polymeric derivative of the latter (P-GFLGG-TAPC-Zn) was synthesized. Spectral data indicated that in aqueous solutions P-GFLGG-TAPC-Zn formed aggregates. The degree of aggregation decreased with increasing concentration of detergents or organic solvents in buffer solutions. Consequently, the release of the drug from carrier catalyzed by thiol proteinases, papain or cathepsin B, took place only in the presence of detergents or organic solvents, i.e., under conditions with a lower probability of aggregate formation. Binding of G-TAPC-Zn to HPMA copolymers decreased the quantum yield of singlet oxygen generation from 0.24 to 0.063 and significantly increased its resistance to photobleaching.

Transport Characteristics of Wheat Germ Agglutinin-Modified Insulin-Liposomes and Solid Lipid Nanoparticles in a Perfused Rat Intestinal Model

2006 ◽  
Vol 6 (9) ◽  
pp. 2959-2966 ◽  
Author(s):  
Na Zhang ◽  
Qineng Ping ◽  
Guihua Huang ◽  
Xiuzhen Han ◽  
Yanna Cheng ◽  
...  
Keyword(s):  
Solid Lipid Nanoparticles ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Serum Insulin ◽  
Lipid Nanoparticles ◽  
Solid Lipid ◽  
Mucosal Absorption ◽  
Perfusion Experiment ◽  
Absorption Sites

Wheat germ agglutinin (WGA) modified liposomes and solid lipid nanoparticles (SLNs) were evaluated for improving intestinal absorption of insulin. In an in situ local intestinal perfusion experiment, formulations containing 100 IU/kg insulin were administered to the duodenum, jejunum, and ileum of fasted rats. As hypothesized, ileum was the best intestinal location for the absorption of insulin-containing liposomes. Serum insulin concentrations decreased for the various formulations in different absorption sites according to the following trends: Duodenum > ileum > jejunum for WGA-modified insulin-containing liposomes; duodenum > jejunum > ileum for WGA-modified insulin-containing SLNs; ileum > jejunum > duodenum for insulin-containing liposomes; ileum > duodenum > jejunum for insulin-containing SLNs; and duodenum ≥ ileum > jejunum for aqueous solution of insulin. These results imply that the nanoparticle type and delivery site were important factors with respect to increasing the bioavailability of insulin following oral administration. The proteolytic degradation as well as the epithelial permeability were primary determinants influcing insulin mucosal absorption.

Identification of distinct haemocyte populations from the freshwater bivalves swan mussel (Anodonta cygnea) and duck mussel (Anodonta anatina) using wheat-germ agglutinin

2017 ◽  
Vol 95 (12) ◽  
pp. 937-947 ◽  
Author(s):  
M. Hinzmann ◽  
M. Lopes-Lima ◽  
F. Cerca ◽  
A. Correia ◽  
J. Machado ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Transmission Microscopy ◽  
Anodonta Cygnea ◽  
Functional Studies ◽  
Lectin Staining ◽  
Surface Staining ◽  
Cytological Features ◽  
Freshwater Bivalves

Haemocytes play a major role in molluscs immunity. Functional studies are, however, impaired by limited available experimental tools to identify and sort distinct haemocyte populations. Therefore, using nonlethal methods, we aimed at evaluating whether lectin staining combined with flow cytometry could be used to distinguish circulating haemocyte populations from two freshwater bivalves of the family Unionidae, the duck mussel (Anodonta anatina (L., 1758)) and the swan mussel (Anodonta cygnea (L., 1758)). Based on classical classification, haemocytes were distinguished as granulocytes and hyalinocytes and cytological features were visualized using transmission microscopy and staining techniques. Size, granularity, viability, and surface staining using lectins as specific probes were analysed by flow cytometry and fluorescence microscopy. The microscopic proportions of granulocytes and hyalinocytes significantly differed, being of 70% and 30% for A. cygnea and of 85% and 15% for A. anatina, respectively. Two haemocyte populations were sorted by flow cytometry based on size and granularity and confirmed as granulocytes and hyalinocytes. Interestingly, two different granulocyte populations could be further discriminated in A. cygnea according to their binding affinity to wheat-germ agglutinin (WGA), whereas granulocytes of A. anatina all stained similarly. Our results show that WGA labelling combined with flow cytometry can be used to better discriminate Anodonta haemocyte populations and obtain purified populations for functional studies.

scholarly journals Cross-Linking Effects Dictate the Preference of Galectins to Bind LacNAc-Decorated HPMA Copolymers

2021 ◽  
Vol 22 (11) ◽  
pp. 6000
Author(s):  
Sara Bertuzzi ◽  
Ana Gimeno ◽  
Ane Martinez-Castillo ◽  
Marta G. Lete ◽  
Sandra Delgado ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lectin Binding ◽  
Building Blocks ◽  
Cryo Electron Microscopy ◽  
Hpma Copolymers ◽  
Hydroxypropyl Methacrylamide ◽  
Galectin 3 ◽  
Nmr Methods ◽  
The Individual ◽  
Statistical Effects

The interaction of multi-LacNAc (Galβ1-4GlcNAc)-containing N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers with human galectin-1 (Gal-1) and the carbohydrate recognition domain (CRD) of human galectin-3 (Gal-3) was analyzed using NMR methods in addition to cryo-electron-microscopy and dynamic light scattering (DLS) experiments. The interaction with individual LacNAc-containing components of the polymer was studied for comparison purposes. For Gal-3 CRD, the NMR data suggest a canonical interaction of the individual small-molecule bi- and trivalent ligands with the lectin binding site and better affinity for the trivalent arrangement due to statistical effects. For the glycopolymers, the interaction was stronger, although no evidence for forming a large supramolecule was obtained. In contrast, for Gal-1, the results indicate the formation of large cross-linked supramolecules in the presence of multivalent LacNAc entities for both the individual building blocks and the polymers. Interestingly, the bivalent and trivalent presentation of LacNAc in the polymer did not produce such an increase, indicating that the multivalency provided by the polymer is sufficient for triggering an efficient binding between the glycopolymer and Gal-1. This hypothesis was further demonstrated by electron microscopy and DLS methods.

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