scholarly journals Peptidoglycan Recognition by Wheat Germ Agglutinin. A View by NMR

2019 ◽  
Vol 14 (5) ◽  
pp. 1934578X1984924 ◽  
Author(s):  
Khouzaima el Biari ◽  
Ángel Gaudioso ◽  
M. Carmen Fernández-Alonso ◽  
Jesús Jiménez-Barbero ◽  
F. Javier Cañada

Wheat germ agglutinin (WGA) is a lectin composed of 4 homologous hevein domains. It has been shown that WGA binds N-acetyl glucosamine (GlcNAc)-related oligosaccharides and has applications as commercial reagent to detect glycans containing such modified residues. Peptidoglycan (PGN), the main component of the bacterial cell wall, is a polymeric material made of repeating disaccharide units of GlcNAc- N-acetylmuramic acid cross-linked with short polypeptide fragments. Wheat germ agglutinin is able to bind bacterial cells, a phenomenon that could correlate with its plant-defense capacities, but there is no information at the molecular level about how WGA binds to the PGN. Herein, we present structural data on the binding of a short PGN fragment to WGA by means of saturation transfer difference nuclear magnetic resonance studies. The results show that the GlcNAc residue establishes the major contacts with WGA, followed by the N-acetylmuramic acid residue. In contrast, the peptide moiety displays minor contacts at the binding site.

2015 ◽  
Vol 119 (44) ◽  
pp. 14076-14085 ◽  
Author(s):  
R. Ravikanth Reddy ◽  
Bandaru V. N. Phani Kumar ◽  
Ganesh Shanmugam ◽  
Balaraman Madhan ◽  
Asit B. Mandal

2021 ◽  
Vol 8 ◽  
Author(s):  
Ridvan Nepravishta ◽  
Serena Monaco ◽  
Marco Distefano ◽  
Roberto Rizzo ◽  
Paola Cescutti ◽  
...  

Biofilms confine bacterial cells within self-produced matrices, offering advantages such as protection from antibiotics and entrapment of nutrients. Polysaccharides are major components in these macromolecular assemblies, and their interactions with other chemicals are of high relevance for the benefits provided by the biofilm 3D molecular matrix. NMR is a powerful technique for the study and characterization of the interactions between molecules of biological relevance. In this study, we have applied multifrequency saturation transfer difference (STD) NMR and DOSY NMR approaches to elucidate the interactions between the exopolysaccharide produced by Burkholderia multivorans C1576 (EpolC1576) and the antibiotics kanamycin and ceftadizime. The NMR strategies presented here allowed for an extensive characterization at an atomic level of the mechanisms behind the implication of the EpolC1576 in the recalcitrance phenomena, which is the ability of bacteria in biofilms to survive in the presence of antibiotics. Our results suggest an active role for EpolC1576 in the recalcitrance mechanisms toward kanamycin and ceftadizime, though through two different mechanisms.


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

2006 ◽  
Vol 6 (9) ◽  
pp. 2959-2966 ◽  
Author(s):  
Na Zhang ◽  
Qineng Ping ◽  
Guihua Huang ◽  
Xiuzhen Han ◽  
Yanna Cheng ◽  
...  

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.


2017 ◽  
Vol 95 (12) ◽  
pp. 937-947 ◽  
Author(s):  
M. Hinzmann ◽  
M. Lopes-Lima ◽  
F. Cerca ◽  
A. Correia ◽  
J. Machado ◽  
...  

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.


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