Mammalian spermatozoa have a surface covered with glycocalyx, consisting of heterogeneous glycoproteins and glycolipids. This complexity arises from diverse monosaccharides, distinct linkages, various isomeric glycans, branching levels, and saccharide sequences. The glycocalyx is synthesized by spermatozoa developing in the testis, and its subsequent alterations during their transit through the epididymis are a critical process for the sperm acquisition of fertilizing ability. In this study, we performed detailed analysis of the glycocalyx on the sperm surface of bull spermatozoa in relation to individual parts of the epididymis using a wide range (24) of lectins with specific carbohydrate binding preferences. Fluorescence analysis of intact sperm isolated from the bull epididymides was complemented by Western blot detection of protein extracts from the sperm plasma membrane fractions. Our experimental results revealed predominant sequential modification of bull sperm glycans with N-acetyllactosamine (LacNAc), followed by subsequent sialylation and fucosylation in a highly specific manner. Additionally, variations in the lectin detection on the sperm surface may indicate the acquisition or release of glycans or glycoproteins. Our study is the first to provide a complex analysis of the bull sperm glycocalyx modification during epididymal maturation.

• Klíčová slova
• cattle, epididymis, glycan, lectin, plasma membrane, sperm surface, spermatozoa,
• MeSH
• epididymis * metabolismus   cytologie   MeSH
• glykokalyx * metabolismus   MeSH
• glykoproteiny metabolismus   MeSH
• lektiny * metabolismus   MeSH
• polysacharidy metabolismus   MeSH
• skot MeSH
• spermie * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• glykoproteiny MeSH
• lektiny * MeSH
• polysacharidy MeSH

Sialic acids are negatively charged carbohydrates that are components of saccharide chains covalently linked to macromolecules. Sialylated glycoproteins are important for most biological processes, including reproduction, where they are associated with spermatogenesis, sperm motility, immune responses, and fertilization. Changes in the glycoprotein profile or sialylation in glycoproteins are likely to affect the quality of ejaculate. The aim of this study was to determine differences in the degree of sialylation between normozoospermic ejaculates and ejaculates with a pathological spermiogram using two lectins, Sambucus nigra (SNA) and Maackia amurensis (MAL II/MAA) recognizing α-2,6 or α-2,3 linkage of Sia to galactosyl residues. Our results show a close relationship between seminal plasma (SP) sialoproteins and the presence of anti-sperm antibodies in the ejaculate, apoptotic spermatozoa, and ejaculate quality. Using mass spectrometry, we identified SP sialoproteins such as, semenogelins, glycodelin, prolactin-inducible protein, lactotransferrin, and clusterin that are associated with spermatozoa and contribute to the modulation of the immune response and sperm apoptosis. Our findings suggest a correlation between the degree of SP glycoprotein sialylation and the existence of possible pathological states of spermatozoa and reproductive organs. Glycoproteins sialylation represents a potential parameter reflecting the overall quality of ejaculate and could potentially be utilised in diagnostics.

• Klíčová slova
• Anti-sperm antibodies, Apoptosis, Ejaculate quality, Glycoprotein, Human,
• MeSH
• analýza spermatu metody   MeSH
• apoptóza MeSH
• ejakulace MeSH
• glykodelin metabolismus   MeSH
• glykoproteiny metabolismus   MeSH
• klusterin metabolismus   MeSH
• kyseliny sialové metabolismus   MeSH
• laktoferrin metabolismus   MeSH
• lektiny metabolismus   chemie   MeSH
• lidé MeSH
• motilita spermií MeSH
• proteiny semenné plazmy metabolismus   MeSH
• sekreční proteiny semenných váčků metabolismus   MeSH
• sperma * metabolismus   chemie   MeSH
• spermie * metabolismus   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• glykodelin MeSH
• glykoproteiny MeSH
• klusterin MeSH
• kyseliny sialové MeSH
• laktoferrin MeSH
• lektiny MeSH
• PAEP protein, human MeSH Prohlížeč
• proteiny semenné plazmy MeSH
• sekreční proteiny semenných váčků MeSH
• seminal vesicle-specific antigen MeSH Prohlížeč

Prostate cancer (PCa) is the second most common cancer. In this paper, the isolation and properties of exosomes as potential novel liquid biopsy markers for early PCa liquid biopsy diagnosis are investigated using two prostate human cell lines, i.e., benign (control) cell line RWPE1 and carcinoma cell line 22Rv1. Exosomes produced by both cell lines are characterised by various methods including nanoparticle-tracking analysis, dynamic light scattering, scanning electron microscopy and atomic force microscopy. In addition, surface plasmon resonance (SPR) is used to study three different receptors on the exosomal surface (CD63, CD81 and prostate-specific membrane antigen-PMSA), implementing monoclonal antibodies and identifying the type of glycans present on the surface of exosomes using lectins (glycan-recognising proteins). Electrochemical analysis is used to understand the interfacial properties of exosomes. The results indicate that cancerous exosomes are smaller, are produced at higher concentrations, and exhibit more nega tive zeta potential than the control exosomes. The SPR experiments confirm that negatively charged α-2,3- and α-2,6-sialic acid-containing glycans are found in greater abundance on carcinoma exosomes, whereas bisecting and branched glycans are more abundant in the control exosomes. The SPR results also show that a sandwich antibody/exosomes/lectins configuration could be constructed for effective glycoprofiling of exosomes as a novel liquid biopsy marker.

• Klíčová slova
• exosomes, microscopy techniques, nanoparticle tracking analysis, prostate cancer, self-assembled monolayer, surface plasmon resonance,
• MeSH
• exozómy * chemie   MeSH
• karcinom * metabolismus   patologie   MeSH
• lektiny analýza   metabolismus   MeSH
• lidé MeSH
• polysacharidy analýza   metabolismus   MeSH
• tekutá biopsie MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• lektiny MeSH
• polysacharidy MeSH

Activation of the lectin pathway of the complement system, as demonstrated by elevated levels of mannan-binding lectin proteins (MBL), contributes to vascular pathology in type 1 diabetes (T1D). Vascular complications are greatest in T1D individuals with concomitant insulin resistance (IR), however, whether IR amplifies activiation of the lectin pathway in T1D is unknown. We pooled pretreatment data from two RCTs and performed a cross-sectional analysis on 46 T1D individuals. We employed estimated glucose disposal rate (eGDR), a validated IR surrogate with cut-points of: <5.1, 5.1-8.7, and > 8.7 mg/kg/min to determine IR status, with lower eGDR values conferring higher degrees of IR. Plasma levels of MBL-associated proteases (MASP-1, MASP-2, and MASP-3) and their regulatory protein MAp44 were compared among eGDR classifications. In a subset of 14 individuals, we assessed change in MASPs and MAp44 following improvement in IR. We found that MASP-1, MASP-2, MASP-3, and MAp44 levels increased in a stepwise fashion across eGDR thresholds with elevated MASPs and MAp44 levels conferring greater degrees of IR. In a subset of 14 patients, improvement in IR was associated with significant reductions in MASPs, but not MAp44, levels. In conclusion, IR in T1D amplifies levels of MASP-1/2/3 and their regulator MAp44, and improvement of IR normalizes MASP-1/2/3 levels. Given that elevated levels of these proteins contribute to vascular pathology, amplification of the lectin pathway of the complement system may offer mechanistic insight into the relationship between IR and vascular complications in T1D.

• Klíčová slova
• complement, insulin resistance, mannan-binding lectin-associated serine proteases, type 1 diabetes,
• MeSH
• diabetes mellitus 1. typu * MeSH
• inzulinová rezistence * MeSH
• komplement MeSH
• lektin vázající mannosu * MeSH
• lektiny metabolismus   MeSH
• lidé MeSH
• průřezové studie MeSH
• serinové proteasy asociované s proteinem vázajícím mannosu metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• komplement MeSH
• lektin vázající mannosu * MeSH
• lektiny MeSH
• serinové proteasy asociované s proteinem vázajícím mannosu MeSH

Trisaccharides bind to their interaction partners-lectins relatively weakly, which makes detection of their complexes challenging. In this work, we show that an osmolyte presence improves the distinguishing complexes of lectin Sambucus nigra with trisialyllactoses with various binding affinities. The addition of osmolyte, non-binding sugar mannose significantly improved the precision of binding experiments performed using chronopotentiometric stripping at the electrode surface and fluorescence analysis in solution. Osmolytes minimized nonspecific interactions between binding sugar and lectin. Obtained findings can be utilized in any in vitro methods studying interactions of carbohydrates, respectively their conjugates with proteins. The study of carbohydrate interactions appears important since they play essential roles in a variety of biological processes including carcinogenesis.

• Klíčová slova
• Chronopotentiometric stripping, Impedance C-t curves, Lectin SNA−1 interactions, Osmolytes, Sialylated trisaccharides, Water arrangement,
• MeSH
• bez černý * chemie   metabolismus   MeSH
• cukry MeSH
• lektiny * metabolismus   MeSH
• trisacharidy metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cukry MeSH
• lektiny * MeSH
• trisacharidy MeSH

Many patients with immunoglobulin A nephropathy (IgAN) progress to kidney failure even with optimal supportive care. An improved understanding of the pathophysiology of IgAN in recent years has led to the investigation of targeted therapies with acceptable tolerability that may address the underlying causes of IgAN or the pathogenesis of kidney injury. The complement system-particularly the lectin and alternative pathways of complement-has emerged as a key mediator of kidney injury in IgAN and a possible target for investigational therapy. This review will focus on the lectin pathway. The examination of kidney biopsies has consistently shown glomerular deposition of mannan-binding lectin (1 of 6 pattern-recognition molecules that activate the lectin pathway) together with IgA1 in up to 50% of patients with IgAN. Glomerular deposition of pattern-recognition molecules for the lectin pathway is associated with more severe glomerular damage and more severe proteinuria and hematuria. Emerging research suggests that the lectin pathway may also contribute to tubulointerstitial fibrosis in IgAN and that collectin-11 is a key mediator of this association. This review summarizes the growing scientific and clinical evidence supporting the role of the lectin pathway in IgAN and examines the possible therapeutic role of lectin pathway inhibition for these patients.

• Klíčová slova
• IgA nephropathy, complement, glomerulonephritis,
• MeSH
• glomerulus patologie   MeSH
• IgA nefropatie * patologie   MeSH
• imunoglobulin A metabolismus   MeSH
• ledviny patologie   MeSH
• lektiny metabolismus   MeSH
• lidé MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• imunoglobulin A MeSH
• lektiny MeSH

Carbohydrate-binding proteins from pathogenic bacteria and fungi have been shown to be implicated in various pathological processes, where they interact with glycans present on the surface of the host cells. These interactions are part of the initial processes of infection of the host and are very important to study at the atomic level. Here, we report the room temperature neutron structures of PLL lectin from Photorhabdus laumondii in its apo form and in complex with deuterated L-fucose, which is, to our knowledge, the first neutron structure of a carbohydrate-binding protein in complex with a fully deuterated carbohydrate ligand. A detailed structural analysis of the lectin-carbohydrate interactions provides information on the hydrogen bond network, the role of water molecules, and the extent of the CH-π stacking interactions between fucose and the aromatic amino acids in the binding site.

• Klíčová slova
• Photorhabdus, carbohydrate-binding, carbohydrates, fully deuterated L-fucose, lectin, ligand binding, neutron macromolecular crystallography (NMX), neutron structure, perdeuteration, stacking interaction,
• MeSH
• bakteriální proteiny chemie   metabolismus   MeSH
• fukosa chemie   metabolismus   MeSH
• lektiny chemie   metabolismus   MeSH
• Photorhabdus chemie   MeSH
• vazba proteinů MeSH
• vodík chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální proteiny MeSH
• fukosa MeSH
• lektiny MeSH
• vodík MeSH

The monolayer character of two-dimensional materials predestines them for application as active layers of sensors. However, their inherent high sensitivity is always accompanied by a low selectivity. Chemical functionalization of two-dimensional materials has emerged as a promising way to overcome the selectivity issues. Here, we demonstrate efficient graphene functionalization with carbohydrate ligands-chitooligomers, which bind proteins of the lectin family with high selectivity. Successful grafting of a chitooligomer library was thoroughly characterized, and glycan binding to wheat germ agglutinin was studied by a series of methods. The results demonstrate that the protein quaternary structure remains intact after binding to the functionalized graphene, and that the lectin can be liberated from the surface by the addition of a binding competitor. The chemoenzymatic assay with a horseradish peroxidase conjugate also confirmed the intact catalytic properties of the enzyme. The present approach thus paves the way towards graphene-based sensors for carbohydrate-lectin binding.

• Klíčová slova
• 2D materials, carbohydrate, graphene, sensor, wheat germ agglutinin,
• MeSH
• grafit chemie   MeSH
• křenová peroxidasa MeSH
• kvarterní struktura proteinů MeSH
• lektiny analýza   metabolismus   MeSH
• polysacharidy chemie   metabolismus   MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• grafit MeSH
• křenová peroxidasa MeSH
• lektiny MeSH
• polysacharidy MeSH

O-methylation is an unusual sugar modification with a function that is not fully understood. Given its occurrence and recognition by lectins involved in the immune response, methylated sugars were proposed to represent a conserved pathogen-associated molecular pattern. We describe the interaction of O-methylated saccharides with two β-propeller lectins, the newly described PLL2 from the entomopathogenic bacterium Photorhabdus laumondii, and its homologue PHL from the related human pathogen Photorhabdus asymbiotica. The crystal structures of PLL2 and PHL revealed up to 10 out of 14 potential binding sites per protein subunit to be occupied with O-methylated structures. The avidity effect strengthens the interaction by 4 orders of magnitude. PLL2 and PHL also interfere with the early immune response by modulating the production of reactive oxygen species and phenoloxidase activity. Since bacteria from Photorhabdus spp. have a complex life cycle involving pathogenicity towards different hosts, the involvement of PLL2 and PHL might contribute to the pathogen overcoming insect and human immune system defences in the early stages of infection. DATABASES: Structural data are available in PDB database under the accession numbers 6RG2, 6RGG, 6RFZ, 6RG1, 6RGU, 6RGW, 6RGJ, and 6RGR.

• Klíčová slova
• Photorhabdus, O-methylation, lectin, phenoloxidase, reactive oxygen species,
• MeSH
• bakteriální proteiny chemie   metabolismus   MeSH
• cukry metabolismus   MeSH
• gramnegativní bakteriální infekce imunologie   metabolismus   mikrobiologie   MeSH
• hemocyty imunologie   metabolismus   MeSH
• hemolymfa imunologie   metabolismus   MeSH
• imunita imunologie   MeSH
• imunitní systém imunologie   metabolismus   MeSH
• interakce hostitele a patogenu imunologie   MeSH
• lektiny chemie   metabolismus   MeSH
• lidé MeSH
• metylace MeSH
• můry MeSH
• Photorhabdus imunologie   metabolismus   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální proteiny MeSH
• cukry MeSH
• lektiny MeSH

Burkholderia pseudomallei and Chromobacterium violaceum are bacteria of tropical and subtropical soil and water that occasionally cause fatal infections in humans and animals. Microbial lectins mediate the adhesion of organisms to host cells, which is the first phase in the development of infection. Here we report the discovery of two novel lectins from the above-mentioned bacteria - BP39L and CV39L. The crystal structures revealed that the lectins possess a seven-bladed β-propeller fold. Functional studies conducted on a series of oligo- and polysaccharides confirmed the preference of BP39L for mannosylated saccharides and CV39L for rather more complex polysaccharides with a monosaccharide preference for β-l-fucose. The presented data indicate that the proteins belong to a currently unknown family of lectins.

• Klíčová slova
• Burkholderia pseudomallei, Chromobacterium violaceum, Lectin, Protein structure, Seven-bladed β-propeller fold,
• MeSH
• bakteriální proteiny metabolismus   MeSH
• Burkholderia pseudomallei metabolismus   MeSH
• Chromobacterium metabolismus   MeSH
• fukosa metabolismus   MeSH
• lektiny metabolismus   MeSH
• lidé MeSH
• monosacharidy metabolismus   MeSH
• polysacharidy metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• fukosa MeSH
• lektiny MeSH
• monosacharidy MeSH
• polysacharidy MeSH