Structural and Functional Characterization of New Lipid Transfer Proteins with Chitin-Binding Properties: Insights from Protein Structure Prediction, Molecular Docking, and Antifungal Activity.

Faced with the emergence of multiresistant microorganisms that affect human health, microbial agents have become a serious global threat, affecting human health and plant crops. Antimicrobial peptides have attracted significant attention in research for the development of new microbial control agents. This work's goal was the structural characterization and analysis of antifungal activity of chitin-binding peptides from Capsicum baccatum and Capsicum frutescens seeds on the growth of Candida and Fusarium species. Proteins were initially submitted to extraction in phosphate buffer pH 5.4 and subjected to chitin column chromatography. Posteriorly, two fractions were obtained for each species, Cb-F1 and Cf-F1 and Cb-F2 and Cf-F2, respectively. The Cb-F1 (C. baccatum) and Cf-F1 (C. frutescens) fractions did not bind to the chitin column. The electrophoresis results obtained after chromatography showed two major protein bands between 3.4 and 14.2 kDa for Cb-F2. For Cf-F2, three major bands were identified between 6.5 and 14.2 kDa. One band from each species was subjected to mass spectrometry, and both bands showed similarity to nonspecific lipid transfer protein. Candida albicans and Candida tropicalis had their growth inhibited by Cb-F2. Cf-F2 inhibited the development of C. albicans but did not inhibit the growth of C. tropicalis. Both fractions were unable to inhibit the growth of Fusarium species. The toxicity of the fractions was tested in vivo on Galleria mellonella larvae, and both showed a low toxicity rate at high concentrations. As a result, the fractions have enormous promise for the creation of novel antifungal compounds.

A fibrinogen-related Lectin from Echinometra lucunter represents a new FReP family in Echinodermata phylum.

Fibrinogen-related proteins (FREPs) have been identified in several animals. They are involved in the body's defense, acting as mediators of phagocytosis. Ficolins and intelectins are some of the most studied Fibrinogen-related Domain (FReD)-containing lectins. In this work, we have isolated a singular FReD-containing lectin, which cannot be classified as ficolin or intelectin. ELL (Echinometra lucunter lectin) was isolated from coelomic plasma by affinity chromatography on xanthan gum. Primary structure was determined by tandem mass spectrometry. Moreover, antimicrobial activity of ELL was evaluated against planktonic cells and biofilm of Escherichia coli, Staphylococcus aureus and S. epidermidis. ELL showed hemagglutinating activity in Ca2+ presence, which was inhibited by glycoprotein mucin and thyroglobulin. Complete amino acid sequence consisted of 229 residues, including a FReD in the N-terminal. Searches for similarity found that ELL was very close to putative proteins from Strongylocentrotus purpuratus. ELL showed moderate similarity with uncharacterized sea stars proteins and protochordate intelectins. ELL was able to inhibit the planktonic growth of the Gram-positive bacteria and significantly reduce the biofilm formation of all bacteria tested. In conclusion, we identified a new type of FReP-containing lectin with some structural and functional conservation towards intelectins.

H2O2 priming induces proteomic responses to defense against salt stress in maize.

KEY MESSAGE: H2O2 priming reprograms essential proteins' expression to help plants survive, promoting responsive and unresponsive proteins adjustment to salt stress. ABSTACRT: Priming is a powerful strategy to enhance abiotic stress tolerance in plants. Despite this, there is scarce information about the mechanisms induced by H2O2 priming for salt stress tolerance, particularly on proteome modulation. Improving maize cultivation in areas subjected to salinity is imperative for the local economy and food security. Thereby, this study aimed to investigate physiological changes linked with post-translational protein events induced by foliar H2O2 priming of Zea mays plants under salt stress. As expected, salt treatment promoted a considerable accumulation of Na+ ions, a 12-fold increase. It drastically affected growth parameters and relative water content, as well as promoted adverse alteration in the proteome profile, when compared to the absence of salt conditions. Conversely, H2O2 priming was beneficial via specific proteome reprogramming, which promoted better response to salinity by 16% reduction in Na+ content and shoots growth improvement, increasing 61% in dry mass. The identified proteins were associated with photosynthesis and redox homeostasis, critical metabolic pathways for helping plants survive in saline stress by the protection of chloroplasts organization and carbon fixation, as well as state redox. This research provides new proteomic data to improve understanding and forward identifying biotechnological strategies to promote salt stress tolerance.

A new mucin-binding lectin from the marine sponge Aplysina fulva (AFL) exhibits antibiofilm effects.

A new mucin-binding lectin (AFL) was isolated from the marine sponge Aplysina fulva. AFL was purified by affinity chromatography on Sepharose™ matrix. Its hemagglutinating activity was independent of divalent ions, and it was weakly inhibited by simple sugars. However, porcine stomach mucin was a powerful inhibitor. In SDS PAGE, piridylethylated AFL showed one band of approximately 16 kDa, whereas in the non-reducing conditions, AFL showed at least two bands of 30 and 70 kDa. Mass spectrometry MALDI-ToF analysis showed one major ion of 31,652 ±â€¯5 Da, which corresponded to a dimer formed by subunits linked by disulfide bonds. The first fifteen amino acids of AFL were determined, and no sequence similarity was observed with any known protein. Internal sequences were obtained by mass spectrometry analysis of tryptic digestion of AFL spots. These peptides showed similarity with a lectin from marine sponge Aplysina lactuca. Secondary structure of AFL was predominantly formed by ß-conformations, which were stable at variations of pH and temperature. AFL did not inhibit planktonic growth of Gram-positive and Gram-negative bacteria tested. However, the lectin did significantly reduce the biomass biofilm of the bacteria Staphylococcus aureus, S. epidermidis, and Escherichia coli.

Proteome of the periovulatory oviduct and uterus of goats as related to nutritional balance.

This study was conducted to evaluate the effects of different feeding levels on the proteome of oviduct and uterus tissues of hormonally stimulated goats during the periovulatory period. Forty goats were separated into four different diet groups: Diet 1.0 M (n = 11), Diet 1.3 M (n = 10), Diet 1.6 M (n = 9), Diet 1.9 M (n = 10), fed with 1.0, 1.3, 1.6 and 1.9 times live weight maintenance, respectively. After four weeks of treatment, six hormonally stimulated females per treatment group were randomly selected for collection of uterine and the oviduct tissue samples. Samples were collected after animals were slaughtered in a commercial unit. Feeding goats with 1.3 to 1.9 times more nutrients than a control group directly influenced the proteome of the oviduct and uterus, altering the expression of proteins that participate in biological processes such as apoptosis, antioxidant, and immunological activities. These events are crucial for fertilization and early embryonic survival. Expression of oviduct proteins such as Tubulin Beta 2B, Transferrin and Disulphide-isomerase A3 increased in the 1.9 M group in relation to the other feeding levels. Disulphide-isomerase A4 showed higher expression in the 1.0 M group compared to diets with higher energetic levels. As energy intake increased in the diets, there was higher expression of Alpha-1-antitrypsin and downregulation of Profilin-1 in the uterus of the goats. In conclusion, this study showed that specific proteins of the goat oviduct and uterus expressed during the periovulatory period are modified as the result of nutritional balance.

The galactose-binding lectin isolated from Bauhinia bauhinioides Mart seeds inhibits neutrophil rolling and adhesion via primary cytokines.

In this study, the amino acid sequence and anti-inflammatory effect of Bauhinia bauhinioides (BBL) lectin were evaluated. Tandem mass spectrometry revealed that BBL possesses 86 amino acid residues. BBL (1 mg/kg) intravenously injected in rats 30 min prior to inflammatory stimuli inhibited the cellular edema induced by carrageenan in only the second phase (21% - 3 h, 19% - 4 h) and did not alter the osmotic edema induced by dextran. BBL also inhibited carrageenan peritoneal neutrophil migration (51%), leukocyte rolling (58%) and adhesion (68%) and the neutrophil migration induced by TNF-α (64%). These effects were reversed by the association of BBL with galactose, demonstrating that the carbohydrate-binding domain is essential for lectin activity. In addition, BBL reduced myeloperoxidase activity (84%) and TNF-α (68%) and IL1-ß (47%) levels. In conclusion, the present investigation demonstrated that BBL contains highly homologous isolectins, resulting in a total of 86 amino acid residues, and exhibits anti-inflammatory activity by inhibiting neutrophil migration by reducing TNF-α and IL1-ß levels via the lectin domain.

A novel vasorelaxant lectin purified from seeds of Clathrotropis nitida: partial characterization and immobilization in chitosan beads.

A novel lectin from seeds of Clathrotropis nitida (CNA) was purified and characterized. CNA is a glycoprotein containing approximately 3.3% carbohydrates in its structure. CNA promoted intense agglutination of rabbit erythrocytes, which was inhibited by galactosides and porcine stomach mucin (PSM). The lectin maintained its hemagglutinating activity after incubation in a wide range of temperatures (30-60 °C) and pH (6.0-7.0), and its binding activity was dependent on divalent cations (Ca(+2) and Mg(+2)). SDS-PAGE showed an electrophoretic profile consisting of a single band of 28 kDa, as confirmed by electrospray ionization mass spectrometry, which indicated an average molecular mass of 27,406 ± 2 Da and the possible presence of isoforms and glycoforms. In addition, CNA exhibited no toxicity to Artemia sp. nauplii and elicited reversible and dose-dependent vasorelaxation in precontracted aortic rings. CNA was successfully immobilized on chitosan beads and was able to capture PSM in solution. This study demonstrated that CNA is a lectin that has potential as a biotechnological tool in glycomics and glycoproteomics applications.

Vasorelaxant activity of Canavalia grandiflora seed lectin: A structural analysis.

Lectins are comprised of a large family of proteins capable of the specific and reversible recognition of carbohydrates. Legume lectins, the most studied plant lectins, show high structural similarity, but with modifications that imply a variation in the intensity of some biological activities. In this work, the primary and tertiary structures of Canavalia grandiflora (ConGF) were determined. ConGF, a lectin isolated from C. grandiflora seeds, is able to induce relaxant activity in rat aortic rings. The complete sequence of ConGF comprises 237 amino acids. This particular protein has primary sequence variations commonly found in lectins from Dioclea and Canavalia genera. The protein structure was solved at 2.3 Å resolution by X-ray crystallography. An X-Man molecule was modeled into the carbohydrate recognition domain. Still, ConGF (30 and 100 µg mL(-1)) elicited 25% of vasorelaxation (IC50=34.48 ± 5.07 µg mL(-1)) in endothelialized aortic rings. A nonselective inhibitor of nitric oxide blocked ConGF relaxant effect, showing mediation by nitric oxide. Key distances between ConGF carbohydrate recognition domain residues were determined in order to explain this effect, in turn revealing some structural aspects that could differentiate lectins from the Canavalia genera with respect to different efficacy in vasorelaxant effect.

Halilectin 1 (H-1) and Halilectin 2 (H-2): two new lectins isolated from the marine sponge Haliclona caerulea.

Two new lectins named Halilectin 1 (H-1) and Halilectin 2 (H-2) were isolated from the marine sponge Haliclona caerulea using a combination of affinity chromatography on stroma fixed onto Sephadex G-25 and cation and anion exchange chromatography. H-1 is a monomeric protein with a molecular mass of 40 kDa estimated using sodium dodecyl sulfate polyacrylamide gel electrophoresis and 15 kDa estimated using a TSK gel. Conversely, H-2 is a homodimeric protein with 15 kDa monomers linked via weak interactions. H-1 more effectively agglutinates trypsinized rabbit erythrocytes, whereas H-2 more effectively agglutinates native rabbit erythrocytes. The hemagglutinating activity of H-1 could be not inhibited by any tested sugars, but H-2 was inhibited by orosomucoid and porcine stomach mucin. Neither lectin was dependent on divalent ions. H-1 was stable at basic pH range and temperatures up to 50 °C, whereas H-2 was stable at acid pH range and temperatures up to 80 °C. The H. caerulea lectins exhibited dose-dependent toxicity against Artemia nauplii. Additionally, 76% of the primary structure of H-2 was determined using tandem mass spectrometry to contain a unique amino acid sequence with no similarity to any members of the animal lectin family.

Vatairea macrocarpa lectin (VML) induces depressive-like behavior and expression of neuroinflammatory markers in mice.

Lectins are proteins capable of reversible binding to the carbohydrates in glycoconjugates that can regulate many physiological and pathological events. Galectin-1, a ß-galactoside-binding lectin, is expressed in the central nervous system (CNS) and exhibits neuroprotective functions. Additionally, lectins isolated from plants have demonstrated beneficial action in the CNS. One example is a lectin with mannose-glucose affinity purified from Canavalia brasiliensis seeds, ConBr, which displays neuroprotective and antidepressant activity. On the other hand, the effects of the galactose-binding lectin isolated from Vatairea macrocarpa seeds (VML) on the CNS are largely unknown. The aim of this study was to verify if VML is able to alter neural function by evaluating signaling enzymes, glial and inflammatory proteins in adult mice hippocampus, as well as behavioral parameters. VML administered by intracerebroventricular (i.c.v) route increased the immobility time in the forced swimming test (FST) 60 min after its injection through a carbohydrate recognition domain-dependent mechanism. Furthermore, under the same conditions, VML caused an enhancement of COX-2, GFAP and S100B levels in mouse hippocampus. However, phosphorylation of Akt, GSK-3ß and mitogen-activated protein kinases named ERK1/2, JNK1/2/3 and p38(MAPK), was not changed by VML. The results reported here suggest that VML may trigger neuroinflammatory response in mouse hippocampus and exhibit a depressive-like activity. Taken together, our findings indicate a dual role for galactose binding lectins in the modulation of CNS function.

Purification, partial characterization and immobilization of a mannose-specific lectin from seeds of Dioclea lasiophylla mart.

Lectin from the seeds of Dioclea lasiophylla (DlyL) was purified in a single step by affinity chromatography on a Sephadex® G-50 column. DlyL strongly agglutinated rabbit erythrocytes and was inhibited by monosaccharides (D-mannose and α-methyl-D-mannoside) and glycoproteins (ovalbumin and fetuin). Similar to other Diocleinae lectins, DlyL has three chains, α, ß and γ, with mass of 25,569 ± 2, 12,998 ± 1 and 12,588 ± 1 Da, respectively, and has no disulfide bonds. The hemagglutinating activity of DlyL was optimal in pH 8.0, stable at a temperature of 70 °C and decreased in EDTA solution, indicating that lectin activity is dependent on divalent metals. DlyL exhibited low toxicity on Artemia sp. nauplii, but this effect was dependent on the concentration of lectin in solution. DlyL immobilized on cyanogen bromide-activated Sepharose® 4B bound 0.917 mg of ovalbumin per cycle, showing the ability to become a tool for glycoproteomics studies.

Inhibition of Serine Protease, α-Amylase and Growth of Phytopathogenic Fungi by Antimicrobial Peptides from Capsicum chinense Fruits.

Plant fungal diseases cause major problems for the global economy. Antimicrobial peptides have aroused great interest in the control of phytopathogens, as they are natural molecules and have a broad spectrum of inhibitory activity. Herein, we have tried to identify and characterize antimicrobial peptides present in fruits of Capsicum chinense and to evaluate their enzymatic and antifungal activities. The retained fraction obtained in the anion exchange chromatography with strong antifungal activity was subjected to molecular exclusion chromatography and obtained four fractions named G1, G2, G3, and G4. The 6.0-kDa protein band of G2 showed similarity with protease inhibitors type II, and it was able to inhibit 100% of trypsin and α-amylase activities. The protein band with approximately 6.5 kDa of G3 showed similarity with sequences of protease inhibitors from genus Capsicum and showed growth inhibition of 48% for Colletotrichum lindemuthianum, 49% for Fusarium lateritium, and 51% for F. solani and F. oxysporum. Additionally, G3 causes morphological changes, membrane permeabilization, and ROS increase in F. oxysporum cells. The 9-kDa protein band of G4 fraction was similar to a nsLTP type 1, and a protein band of 6.5 kDa was similar to a nsLTP type 2. The G4 fraction was able to inhibit 100% of the activities of glycosidases tested and showed growth inhibition of 35 and 50% of F. oxysporum and C. lindemuthianum, respectively. C. chinense fruits have peptides with antifungal activity and enzyme inhibition with biotechnological potential.

Trypsin/α-Amylase Inhibitors from Capsicum chinense Seeds: Characterization and Antifungal Activity against Fungi of Agronomic Importance.

BACKGROUND: Protease inhibitors (PIs) have attracted attention due to their important roles in plant defense. OBJECTIVE: The objective of this work was to characterize and evaluate the antimicrobial activity of the peptides of a family of serine PIs from Capsicum chinense Jacq. seeds. METHODS: Initially, PIs were extracted from the seeds and subjected to purification by chromatography, resulting in three different peptide enriched fractions (PEFs) termed PEF1, PEF2 and PEF3. Subsequently, the PEF3 was subjected to trypsin inhibition assays, α-amylase activity assays, antimicrobial activity assays on phytopathogenic fungi, and assays to determine the likely mechanisms of action. RESULTS: The PEF3 was composed of three protein bands with molecular masses ranging between 6 and 14 kDa. The amino acid residues of the ~6 kDa band showed high similarity with serine PIs. PEF3 inhibited the activity of the enzymes trypsin, human salivary α-amylase, and Tenebrio molitor larval α-amylase and inhibited the growth of phytopathogenic fungi, showing 83.7% loss of viability in Fusarium oxysporum. PEF3 induced reactive oxygen species in Colletotrichum lindemuthianum and F. oxysporum to dissipate their mitochondrial membrane potential and activated caspases in C. lindemuthianum. CONCLUSION: Our results reinforce the importance of PIs in plant defense mechanisms against phytopathogenic fungi as well as in their biotechnological applications for the control of plant pathogens.

Structural characterization of a galectin from the marine sponge Aplysina lactuca (ALL) with synergistic effects when associated with antibiotics against bacteria.

Lectins presents the ability to interact with glycans and trigger varied responses, including the inhibition of the development of various pathogens. Structural studies of these proteins are essential to better understand their functions. In marine sponges, so far only a few lectins have their primary structures completely determined. Thus, the objective of this work was to structurally characterize and evaluate antibacterial potential, in association with different antibiotics, of the lectin isolated from the marine sponge Aplysina lactuta (ALL). ALL is a homotetramer of 60 kDa formed by four 15 kDa-subunits. The lectin showed affinity only for the glycoproteins fetuin, asialofetuin, mucin type III, and bovine submaxillary mucin type I. The complete amino acid sequences of two isoforms of ALL, named ALL-a and ALL-b, were determined by a combination of Edman degradation and overlapped peptides sequenced by tandem mass spectrometry. ALL-a and ALL-b have 144 amino acids with molecular masses of 15,736 Da and 15,985 Da, respectively. Both structures contain conserved residues typical of the galectin family. ALL is a protein with antibacterial potential, when in association with ampicillin and oxacillin the lectin potentiates its antibiotic effect, included Methicillin-resistant Staphylococcus strains. Thus, ALL shows to be a molecule with potential for the development of new antibacterial drugs.

Chia (Salvia hispanica L.) Seeds Contain a Highly Stable Trypsin Inhibitor with Potential for Bacterial Management Alone or in Drug Combination Therapy with Oxacillin.

The emergence of antibiotic resistance poses a serious and challenging threat to healthcare systems, making it imperative to discover novel therapeutic options. This work reports the isolation and characterization of a thermostable trypsin inhibitor from chia (Salvia hispanica L.) seeds, with antibacterial activity against Staphylococcus aureus sensitive and resistant to methicillin. The trypsin inhibitor ShTI was purified from chia seeds through crude extract heat treatment, followed by affinity and reversed-phase chromatography. Tricine-SDS-PAGE revealed a single glycoprotein band of ~ 11 kDa under nonreducing conditions, confirmed by mass spectrometry analysis (11.558 kDa). ShTI was remarkably stable under high temperatures (100 °C; 120 min) and a broad pH range (2-10; 30 min). Upon exposure to DTT (0.1 M; 120 min), ShTI antitrypsin activity was partially lost (~ 38%), indicating the participation of disulfide bridges in its structure. ShTI is a competitive inhibitor (Ki = 1.79 × 10-8 M; IC50 = 1.74 × 10-8 M) that forms a 1:1 stoichiometry ratio for the ShTI:trypsin complex. ShTI displayed antibacterial activity alone (MICs range from 15.83 to 19.03 µM) and in combination with oxacillin (FICI range from 0.20 to 0.33) against strains of S. aureus, including methicillin-resistant strains. Overproduction of reactive oxygen species and plasma membrane pore formation are involved in the antibacterial action mode of ShTI. Overall, ShTI represents a novel candidate for use as a therapeutic agent for the bacterial management of S. aureus infections.

Structural study and antimicrobial and wound healing effects of lectin from Solieria filiformis (Kützing) P.W.Gabrielson.

The SfL-1 isoform from the marine red algae Solieria filiformis was produced in recombinant form (rSfL-1) and showed hemagglutinating activity and inhibition similar to native SfL. The analysis of circular dichroism revealed the predominance of ß-strands structures with spectra of ßI-proteins for both lectins, which had Melting Temperature (Tm) between 41 °C and 53 °C. The three-dimensional structure of the rSfL-1 was determined by X-ray crystallography, revealing that it is composed of two ß-barrel domains formed by five antiparallel ß chains linked by a short peptide between the ß-barrels. SfL and rSfL-1 were able to agglutinate strains of Escherichia coli and Staphylococcus aureus and did not show antibacterial activity. However, SfL induced a reduction in E. coli biomass at concentrations from 250 to 125 µg mL-1, whereas rSfL-1 induced reduction in all concentrations tested. Additionally, rSfL-1 at concentrations from 250 to 62.5 µg mL-1, showed a statistically significant reduction in the number of colony-forming units, which was not noticed for SfL. Wound healing assay showed that the treatments with SfL and rSfL-1 act in reducing the inflammatory response and in the activation and proliferation of fibroblasts by a larger and fast deposition of collagen.

Protein crystal content analysis by mass spectrometry and preliminary X-ray diffraction of a lectin from Canavalia grandiflora seeds with modulatory role in inflammation.

RATIONALE: Lectins are a family of proteins capable of deciphering the glycan code. Several authors have published works about crystallization and mass spectrometry analyses of ConA-like lectins. However, mass spectrometry has never been used to characterize lectin crystal content. In this study, Canavalia grandiflora lectin (ConGF), a ConA-like lectin, was crystallized, part of its primary structure sequenced and the pro-inflammatory activity evaluated. In addition, the crystal content was analyzed by mass spectrometry. METHODS: ConGF was crystallized in the presence of X-Man by hanging-drop vapor diffusion at 293 K and the protein crystal content was analyzed by electrospray ionization in a SYNAPT HDMS mass spectrometer. Partial sequence was obtained by protein digestion with several proteolytic enzymes and the peptides sequenced by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The pro-inflammatory potential of ConGF was also evaluated in the model of rat paw edema. RESULTS: The protein crystals consist of mature α chain and ß and γ fragments measuring 25 612 ± 2 Da, 12 962 ± 2 Da and 12 667 ± 2 Da, respectively. The crystal belongs to the orthorhombic space group I222 (unit cell parameters: a = 67.70, b = 55.90, c = 107.46 Å), assuming a monomer in the asymmetric unit. The solvent content was calculated as 43.50% and the protein content as 2.5 µg. Furthermore, a significant part of the primary structure (65.8%) was determined by mass spectrometry. CONCLUSIONS: As far as we know this is the first report of lectin crystal content characterized by mass spectrometry. Like other ConA-like lectins, GonGF induced paw edema however differing in potency and duration. The observed pro-inflammatory activity suggests that ConGF might be a useful tool in the study of inflammation processes and structure/function relationships.

Characterization of isoforms of the lectin isolated from the red algae Bryothamnion seaforthii and its pro-healing effect.

Lectins are a structurally heterogeneous group of proteins that have specific binding sites for carbohydrates and glycoconjugates. Because of their biotechnological potential, lectins are widely used in biomedical research. The present study aimed to evaluate the healing potential of the lectin isolated from the marine red alga Bryothamnion seaforthii (BSL). The lectin was purified using ion exchange chromatography with DEAE cellulose and characterized using tandem mass spectrometry. For healing tests, skin wounds were induced in the dorsal thoracic region of mice. These animals were randomly divided into three groups and subjected to topical treatment for 12 days with BSL, bovine serum albumin and 150 mM NaCl. To evaluate the potential of each treatment, the animals were anesthetized and sacrificed on days 2, 7 and 12, respectively. The parameters evaluated included the wound area, the proportion of wound closure and the histological diagnosis. The wound closure was more effective with BSL (Postoperative Day 7 and 12) than controls. The luminal epithelium was completely restructured; the presence of collagen in the dermis and the strongly active presence of young skin annexes demonstrate the potential of treatment with BSL compared with controls. Our findings suggest that BSL has pro-healing properties and can be a potential medical process in the treatment of acute wounds.

Codium isthmocladum lectin 1 (CiL-1): Interaction with N-glycans explains antinociceptive and anti-inflammatory activities in adult zebrafish (Danio rerio).

Inflammation and oxidative stress are processes associated with different human diseases. They are treated using drugs that have several side effects. Seaweed are sources of potentially relevant natural compounds for use as treatment of these disorders. Lectins are able to reversibly interact with complex carbohydrates and modulate cell membrane glycosylated receptors through this interaction. This study aimed to determine the antinociceptive and anti-inflammatory potential of CiL-1 in adult zebrafish by modulation of TRPA1 through lectin-glycan binding. Possible neuromodulation by TRPA1 channel was also evaluated by camphor pretreatment. CiL-1 was efficacious at all tested doses, revealing anti-nociceptive and anti-inflammatory effects in adult zebrafish. This galactose-binding lectin was also able to reduce the content of ROS in brain and liver. In silico analyses showed CiL-1 interactions with both ligands tested. LacNac2 presents the most favorable binding energy with the protein. The interaction occurs at 4 subsites as an extended conformation at the site. LacNac2-Sia had a less favorable curved-shape interaction energy. Based on the predictions made for the oligosaccharides, a tetra-antenate putative glycan was schematically constructed, illustrating an interaction between TRPA1 N-glycan and CiL-1. This binding seems to be related to CiL-1 anti-inflammatory activity as result of receptor modulation.

Structural analysis of ConBr reveals molecular correlation between the carbohydrate recognition domain and endothelial NO synthase activation.

Diocleinae lectins are highly homologous in their primary structure which features metal binding sites and a carbohydrate recognition domain (CRD). Differences in the biological activity of legume lectins have been widely investigated using hemagglutination inhibition assays, isothermal titration microcalorimetry and co-crystallization with mono- and oligosaccharides. Here we report a new lectin crystal structure (ConBr) extracted from seeds of Canavalia brasiliensis, predict dimannoside binding by docking, identify the α-aminobutyric acid (Abu) binding pocket and compare the CRD of ConBr to that of homologous lectins. Based on the hypothesis that the carbohydrate affinity of lectins depends on CRD configuration, the relationship between tridimensional structure and endothelial NO synthase activation was used to clarify differences in biological activity. Our study established a correlation between the position of CRD amino acid side chains and the stimulation of NO release from endothelium.