Beyond carbohydrate binding: new directions in plant lectin research

Isolation, Purification, and Characterization of Lectins from Medicinal Plant Combretum glutinosum Seeds Endowed with Analgesic and Antiulcer Properties

In the pursuit of safer and more effective treatments, there is a growing interest in plant-derived compounds, particularly lectins, because of their diverse pharmacological properties. This study focused on isolating, purifying, and characterizing lectin from Combretum glutinosum seeds (CGSLs) to assess its potential as an analgesic and antiulcer agent. CGSL extraction involved defatting and buffer extraction, followed by purification using ammonium sulfate fractionation and fetuin-agarose affinity column chromatography. The isolectins (iso-CGSLs), each consisting of 60 kDa and 57 kDa heterodimeric subunits, displayed glycoprotein properties with a 40% neutral sugar content. They exhibited peak activity at 55°C and remained stable for up to the fifth day at room temperature. The activity exhibited a pH dependence, peaking between 7.5 and 10.5, and all seemingly operated independently of metal ions. CGSL, at optimal doses ranging from 6 to 12 mg/kg, had significant analgesic effects on acetic acid-induced writhing and hot plate tests in mice. Evaluation using 0.7% acetic acid resulted in notable pain reduction across all doses (P<0.05). The analgesic effect of lectin was partially reversed by naloxone (a morphine antagonist), indicating partial involvement of the opioid receptor system. Furthermore, CGSL exhibited antiulcer effects in ethanol-induced gastric ulcer models in rats, highlighting its therapeutic potential as a natural alternative for analgesic and antiulcer treatments.

Lectins as the prominent potential to deliver bioactive metal nanoparticles by recognizing cell surface glycans

Lectins are renowned for recognizing specific carbohydrates, but there is evidence that they can bind to other endogenous ligands. Therefore, lectin can be used as a carrier to recognize glycoconjugates on the cell surface. The anticancer, antibacterial, and immunomodulatory properties of some lectins are established. Metal nanoparticles (MNPs) have been used in various fields recently, but their documented toxicity has raised questions about their suitability for biomedical uses. The advantages of MNPs can be realized if we deliver the NPs to the site of action; as a result, NPs may achieve greater therapeutic efficiency at lower doses with less toxicity. The use of carbohydrate specificity by lectin MNPs conjugates for diagnostics and therapeutics was addressed. The review summarised the multidimensional application of lectins and described their potential for delivery of MNPs in future drug development.

Recent Insights into Glucose-Responsive Concanavalin A-Based Smart Hydrogels for Controlled Insulin Delivery

Many efforts are continuously undertaken to develop glucose-sensitive biomaterials able of controlling glucose levels in the body and self-regulating insulin delivery. Hydrogels that swell or shrink as a function of the environmental free glucose content are suitable systems for monitoring blood glucose, delivering insulin doses adapted to the glucose concentration. In this context, the development of sensors based on reversible binding to glucose molecules represents a continuous challenge. Concanavalin A (Con A) is a bioactive protein isolated from sword bean plants (Canavalia ensiformis) and contains four sugar-binding sites. The high affinity for reversibly and specifically binding glucose and mannose makes Con A as a suitable natural receptor for the development of smart glucose-responsive materials. During the last few years, Con A was used to develop smart materials, such as hydrogels, microgels, nanoparticles and films, for producing glucose biosensors or drug delivery devices. This review is focused on Con A-based materials suitable in the diagnosis and therapeutics of diabetes. A brief outlook on glucose-derived theranostics of cancer is also presented.

Effect of temperature and pH on the structure and stability of tumor-specific lectin jacalin and insights into the location of its tryptophan residues: CD, DSC and fluorescence studies

Jacalin, the jackfruit seed lectin, exhibits high specificity for the tumor-specific T-antigen and is used in various biomedical and biotechnological applications. Here, we report biophysical studies on the thermal unfolding of jacalin and the effect of pH and temperature on its secondary structure. Differential scanning calorimetric (DSC) studies revealed that native jacalin unfolds at ∼60 °C and that carbohydrate binding stabilizes the protein structure. Circular dichroism spectroscopic studies indicated that the secondary structure of jacalin remains mostly unaffected over pH 2.0-9.0, whereas considerable changes were observed in the tertiary structure. DSC experiments demonstrated that jacalin exhibits two overlapping transitions between pH 2 and 5, which could be attributed to dissociation of the tetrameric protein into subunits and their unfolding. Interestingly, only one transition between pH 6 and 9 was observed, suggesting that the subunit dissociation and unfolding occur simultaneously. While quenching of the protein intrinsic fluorescence by acrylamide increased significantly upon carbohydrate binding, quenching by succinimide is essentially unaffected. We attribute this difference to increased exposure of Trp-123 in the α-chain as it is involved in carbohydrate binding. Both acrylamide and succinimide gave biphasic Stern-Volmer plots, consistent with differential accessibility of the two tryptophan residues of jacalin to them.

Glycan-specific molecularly imprinted polymers towards cancer diagnostics: merits, applications, and future perspectives

Aberrant glycans are a hallmark of cancer states. Notably, emerging evidence has demonstrated that the diagnosis of cancers with tumour-specific glycan patterns holds great potential to address unmet medical needs, especially in improving diagnostic sensitivity and selectivity. However, despite vast glycans having been identified as potent markers, glycan-based diagnostic methods remain largely limited in clinical practice. There are several reasons that prevent them from reaching the market, and the lack of anti-glycan antibodies is one of the most challenging hurdles. With the increasing need for accelerating the translational process, numerous efforts have been made to find antibody alternatives, such as lectins, boronic acids and aptamers. However, issues concerning affinity, selectivity, stability and versatility are yet to be fully addressed. Molecularly imprinted polymers (MIPs), synthetic antibody mimics with tailored cavities for target molecules, hold the potential to revolutionize this dismal progress. MIPs can bind a wide range of glycan markers, even those without specific antibodies. This capacity effectively broadens the clinical applicability of glycan-based diagnostics. Additionally, glycoform-resolved diagnosis can also be achieved through customization of MIPs, allowing for more precise diagnostic applications. In this review, we intent to introduce the current status of glycans as potential biomarkers and critically evaluate the challenges that hinder the development of in vitro diagnostic assays, with a particular focus on glycan-specific recognition entities. Moreover, we highlight the key role of MIPs in this area and provide examples of their successful use. Finally, we conclude the review with the remaining challenges, future outlook, and emerging opportunities.

Spectroscopic and thermodynamic characterization of the interaction between sugar-stabilised silver nanoparticles and wheat germ agglutinin (WGA), a chitin binding lectin

Nanomaterials have lately been investigated in agriculture as eco-friendly and effective antifungal agents. Many nanomaterials, notably metal nanoparticles, have strong antifungal properties. Among metal nanoparticles, Ag nanoparticles have received the most attention as antifungal agents. Many plant lectins have been identified as antifungal agents. Conjugating AgNPs with antifungal lectins is thus expected to improve Ag nanoparticle antifungal efficacy. Understanding the molecular interactions and physical features of lectin-sugar-stabilised nanoparticle conjugates is critical for future applications. WGA has traditionally been used as an anti-tumor and antifungal agent. To investigate the prospect of developing an effective biocompatible antifungal system with applications in medicine and agriculture, fluorescence spectroscopy was used to investigate the interaction between sugar-stabilised silver nanoparticles and WGA. During the association, protein intrinsic fluorescence emission is suppressed by about ∼15 % at saturation, with no significant shift in fluorescence emission maxima. Binding tests reveal a strong bond. Stern-Volmer analysis of the quenching data indicates that the interaction happens via a static quenching process that induces complex formation. The study of hemagglutination activity and interaction experiments in the presence of particular sugar shows that the lectin's sugar-binding site is separate from the nanoparticle-binding site, and cell recognition is conserved in the lectin-nanoparticle complex. The Van't Hoff plot thermodynamic parameters suggest that the contact is hydrophobic. The fact that ΔGo is negative shows that the binding is a spontaneous process. CD spectroscopy experiments reveal that the lectin's secondary structure is not affected while binding to the nanoparticle. Our findings suggest that a stable WGA-silver nanoparticle combination may emerge for a variety of applications.

A Review of the Leishmanicidal Properties of Lectins

Lectins are proteins widely distributed among plants, animals and microorganisms that have the ability to recognize and interact with specific carbohydrates. They have varied biological activities, such as the inhibition of the progression of infections caused by fungi, bacteria, viruses and protozoa, which is related to the interaction of these proteins with the carbohydrates present in the cell walls of these microorganisms. Leishmaniasis are a group of endemic infectious diseases caused by protozoa of the genus Leishmania. In vitro and in vivo tests with promastigotes and amastigotes of Leishmania demonstrated that lectins have the ability to interact with glycoconjugates present on the cell surface of the parasite, it prevents their development through various mechanisms of action, such as the production of ROS and alteration of membrane integrity, and can also interact with defense cells present in the human body, thus showing that these molecules can be considered alternative pharmacological targets for the treatment of leishmaniasis. The objective of the present work is to carry out a bibliographic review on lectins with leishmanicidal activity, emphasizing the advances and perspectives of research in this theme. Through the analysis of the selected studies, we were able to conclude that lectins have great potential for inhibiting the development of leishmaniasis. However, there are still few studies on this subject.

Jacalin-Curcumin Complex Sensitizes the Breast Cancer MDA-MB-231 Cell Line

Protein-drug interactions are crucial for understanding drug delivery and cell functions. Jacalin is a suitable molecule for such targeting, as it specifically recognizes the tumor-associated Thomsen-Friedenreich (TF) antigen that is expressed on the glycosylated proteins in cancer cells. The present paper describes the interaction of curcumin and jacalin, a possible carrier molecule for the delivery of antitumor drugs due to its ability to recognize tumor cells. Our results have shown that both steady-state fluorescence and fluorescent labelling of jacalin are two reliable methods to determine jacalin-curcumin interactions. The affinity of jacalin for curcumin is consistently within the micromolar range (using fluorescence and microscale thermophoresis) showing high-affinity binding of the complex. In vitro experiments on triple-negative breast cancer MDA-MB-231 cells indicated inhibition of cell growth after treating with the jacalin-curcumin complex for 48 h. The cell survival fraction was significantly reduced to 50% after combined treatment. In this paper, we report for the first time about the jacalin-curcumin interaction. We quantified this unique biomolecular interaction and gathered additional information on the binding event. We observed that the jacalin-curcumin complex inhibits the proliferation of the triple-negative breast cancer MDA-MB-231 cells.

Structural and functional analysis of a novel galactose-binding lectin derived from Chlorella sorokiniana MW769776

A freshwater green microalgal strain was isolated and the lectin was identified in it by a strong hemagglutination activity (HA) assay. Characterization of the algal strain was found to be Chlorella sorokiniana (MW769776). A single step affinity chromatographic technique was developed to purify Chlorella sorokiniana lectin (CSL) using guar gum as the affinity matrix. The precipitate showed a single active peak with a titer value of 1024 HU, with a concentration of 1111 U, and a purification fold of 9. The purified protein exhibited a single band in SDS-PAGE with a molecular weight of 16 kDa. Analysis by liquid chromatography-electrospray ionization-quadrupole-time of flight mass spectrometry (LC-ESI-Q-TOF-MS) of tryptic-digested purified lectin showed that it was a monomeric protein. A multiple sequence alignment analysis revealed that the peptide sequences of CSL exhibited similarity with the H-type lectin domain of Micractinium conductrix. The structure of CSL was studied by FTIR and homology modeling methods, indicating the presence of α-helix as well as β-sheet in its secondary structure. Whereas the 3D structure exhibited the similarity with the core protein of light-harvesting reaction center complex of photosystem I. The significance of this study suggests that the characteristics of CSL are consistent with its identification as a hemagglutinin, a type of novel lectin, which suggests its candidature for various biological purposes.Communicated by Ramaswamy H. Sarma.

Plant lectins: Classical molecules with emerging roles in stress tolerance

Biotic and abiotic stresses impose adverse effects on plant's development, growth, and production. For the past many years, researchers are trying to understand the stress induced responses in plants and decipher strategies to produce stress tolerant crops. It has been demonstrated that molecular networks encompassing an array of genes and functional proteins play a key role in generating responses to combat different stresses. Newly, there has been a resurgence of interest to explore the role of lectins in modulating various biological responses in plants. Lectins are naturally occurring proteins that form reversible linkages with their respective glycoconjugates. To date, several plant lectins have been recognized and functionally characterized. However, their involvement in stress tolerance is yet to be comprehensively analyzed in greater detail. The availability of biological resources, modern experimental tools, and assay systems has provided a fresh impetus for plant lectin research. Against this backdrop, the present review provides background information on plant lectins and recent knowledge on their crosstalks with other regulatory mechanisms, which play a remarkable role in plant stress amelioration. It also highlights their versatile role and suggests that adding more information to this under-explored area will usher in a new era of crop improvement.

Subunit association, and thermal and chemical unfolding of Cucurbitaceae phloem exudate lectins. A review

Detailed characterization of protein (un)folding intermediates is crucial for understanding the (un)folding pathway, aggregation, stability and their functional properties. In recent years, stress-inducible lectins are being investigated with much interest. In plants phloem proteins PP1 and PP2 are major components of the phloem fluid. While PP1 is a structural protein, PP2 exhibits lectin activity, and was proposed to play key roles in wound sealing, anti-pathogenic activity, and transportation of various molecules including RNA within the plant. Cucurbitaceae fruits contain high concentrations of PP2 lectins, which recognize chitooligosaccharides with high specificity. Although the presence of PP2 lectins in the phloem exudate of Cucurbitaceae species was documented over 40 years ago, so far only a few proteins from this family have been purified and characterized in detail. This review summarizes the results of biophysical studies aimed at investigating the oligomeric status of these lectins, their thermal stability, structural perturbations caused by changes in pH and addition of chaotropic agents and characterization of intermediates observed in the unfolding process. The implications of these results in the functional roles played by PP2 type lectins in their native environment are discussed. Finally, perspectives for future biophysical research on these proteins are given.

Interaction of sugar stabilised silver nanoparticles with Momordica charantia seed lectin, a type II ribosome inactivating protein

Sugar-stabilised nanomaterials have received a lot of attention in cancer therapy in recent years due to their pronounced application as specific targeting agents and maximizing their therapeutic potential while bypassing off-target effects. Lectins, the carbohydrate-binding proteins, are capable of binding to receptors present on the target cell/tissue and interact with transformed glycans better than normal cells. Besides some of the lectins exhibit anticancer activity. Conjugating sugar-stabilised NPs with lectins there for is expected to multiply the potential for the early diagnosis of cancer cells and the specific release of drugs into the tumor site. Because of the prospective applications of lectin-sugar-stabilised nanoparticle conjugates, it is important to understand their molecular interaction and physicochemical properties. Momordica charantia Seed Lectin (MCL) is a type II RIP and has been known as an anti-tumor agent. Investigation of the interaction between sugar-stabilised silver nanoparticles and MCL has been performed by fluorescence spectroscopy to explore the possibility of creating an effective biocompatible drug delivery system against cancer cells. In this regard interaction between lectin and NPs should be well-preserved, while recognizing the specific cell surface sugar. Therefore experiments were carried out in the presence and absence of specific sugar galactose. Protein intrinsic fluorescence emission is quenched at ~ 20% at saturation during the interaction without any significant shift in fluorescence emission maximum. Binding experiments reveal a good affinity. Tetrameric MCL binds to a single nanoparticle. Stern-Volmer analysis of the quenching data suggests that the interaction is via static quenching leading to complex formation. Hemagglutination experiments together with interaction studies in the presence of specific sugar show that the sugar-binding site of the lectin is distinct from the nanoparticle-binding site and cell recognition is very much intact even after binding to AgNPs. Our results propose the possibility of developing MCL-silver nanoparticle conjugate with high stability and multiple properties in the diagnosis and treatment of cancer.

A galactoside-specific Dalbergieae legume lectin from seeds of Vataireopsis araroba (Aguiar) Ducke

The Dalbergieae lectin group encompasses several lectins with significant differences in their carbohydrate specificities and biological properties. The current work reports on the purification and characterization of a GalNAc/Gal-specific lectin from Vataireopsis araroba (Aguiar) Ducke, designated as VaL. The lectin was purified from the seeds in a single step using guar gum affinity chromatography. The lectin migrated as a single band of about 35 kDa on SDS-PAGE and, in native conditions, occurs as a homodimer. The purified lectin is stable at temperatures up to 60 °C and in a pH range from 7 to 8 and requires divalent cations for its activity. Sugar-inhibition assays demonstrate the lectin specificity towards N-acetyl-D-galactosamine, D-galactose and related sugars. Furthermore, glycan array analyses show that VaL interacts preferentially with glycans containing terminal GalNAc/Galβ1-4GlcNAc. Biological activity assays were performed using three insect cell lines: CF1 midgut cells from the spruce budworm Choristoneura fumiferana, S2 embryo cells from the fruit fly Drosophila melanogaster, and GutAW midgut cells from the corn earworm Helicoverpa zea. In vitro assays indicated a biostatic effect for VaL on CF1 cells, but not on S2 and GutAW cells. The lectin presented a biostatic effect by reducing the cell growth and inducing cell agglutination, suggesting an interaction with glycans on the cell surface. VaL has been characterized as a galactoside-specific lectin of the Dalbergieae tribe, with sequence similarity to lectins from Vatairea and Arachis.

Seed Storage Protein, Functional Diversity and Association with Allergy

Plants are essential for humans as they serve as a source of food, fuel, medicine, oils, and more. The major elements that are utilized for our needs exist in storage organs, such as seeds. These seeds are rich in proteins, show a broad spectrum of physiological roles, and are classified based on their sequence, structure, and conserved motifs. With the improvements to our knowledge of the basic sequence and our structural understanding, we have acquired better insights into seed proteins and their role. However, we still lack a systematic analysis towards understanding the functional diversity associated within each family and their associations with allergy. This review puts together the information about seed proteins, their classification, and diverse functional roles along with their associations with allergy.

Plant Lectins: A Review on their Biotechnological Potential Toward Human Pathogens

The indiscriminate use of antibiotics is associated with the appearance of bacterial resistance. In light of this, plant-based products treating infections are considered potential alternatives. Lectins are a group of proteins widely distributed in nature, capable of reversibly binding carbohydrates. Lectins can bind to the surface of pathogens and cause damage to their structure, thus preventing host infection. The antimicrobial activity of plant lectins results from their interaction with carbohydrates present in the bacterial cell wall and fungal membrane. The data about lectins as modulating agents of antibiotic activity, potentiates the effect of antibiotics without triggering microbial resistance. In addition, lectins play an essential role in the defense against fungi, reducing their infectivity and pathogenicity. Little is known about the antiviral activity of plant lectins. However, their effectiveness against retroviruses and parainfluenza is reported in the literature. Some authors still consider mannose/ glucose/N-Acetylglucosamine binding lectins as potent antiviral agents against coronavirus, suggesting that these lectins may have inhibitory activity against SARS-CoV-2. Thus, it was found that plant lectins are an alternative for producing new antimicrobial drugs, but further studies still need to decipher some mechanisms of action.

In-Vitro Growth Kinetics of Mesenchymal Stem Cells in Cytotoxicity Tests Using Low-Diluted Viscum Album

INTRODUCTION

 The use of mesenchymal stem cells (MSC) in cytotoxicity tests is an in-vitro alternative model for predicting initial doses. Homeopathic medicines may stimulate the immune system to combat a pathology effectively and have been used for over two centuries. Viscum album (VA) extracts are widely used in the treatment of cancer, due to their immunomodulatory, cytotoxic and pro-apoptotic properties.

OBJECTIVE

 This study aimed to evaluate the in-vitro growth kinetics of canine MSC in relation to cytotoxicity, cell differentiation and expression of pluripotentiality markers, using a VA preparation at the D1D2 (1×10^-1, 1×10^-2 potency (VAD1D2).

METHODS

 MSC were obtained from adipose tissue sampled from a healthy dog that was undergoing an elective veterinary procedure and with its owner's permission. The experiments were performed in three groups: MSC treated with VAD1D2 or diluent or untreated (control). The cytotoxicity was evaluated by MTT assay. The differentiation was induced in three lineages, and apoptotic cell labeling was performed by an Annexin-V test.

RESULTS

 At the concentration of 10 μL/mL of VA, the number of cells after in-vitro culture was maintained when compared with the control (untreated) group. A significant and gradual decrease in cell viability was recorded as VA concentrations increased. The apoptosis analysis showed that VA at 20 μL/mL presented absolute percentages of initial apoptosis twice as high as at 10 μL/mL, which was similar to the control (untreated group).

CONCLUSION

 The results suggest that the use of efficient methods to assess the in-vitro cytotoxicity of VA-based homeopathic medicines using MSC lineages may predict the potential action at different concentrations. These findings demonstrated that VAD1D2 interferes with canine MSC growth kinetics.

Phosphate-Solubilizing Pseudomonas sp. Strain WS32 Rhizosphere Colonization-Induced Expression Changes in Wheat Roots

Rhizosphere colonization is a pre-requisite for the favorable application of plant growth-promoting rhizobacteria (PGPR). Exchange and mutual recognition of signaling molecules occur frequently between plants and microbes. Here, the luciferase luxAB gene was electrotransformed into the phosphate-solubilizing strain Pseudomonas sp. WS32, a type of plant growth-promoting rhizobacterium with specific affinity for wheat. A labeled WS32 strain (WS32-L) was applied to determine the temporal and spatial traits of colonization within the wheat rhizosphere using rhizoboxes experimentation under natural condition. The effects of colonization on wheat root development and seedling growth were evaluated, and RNA sequencing (RNA-seq) was performed to explore the transcriptional changes that occur in wheat roots under WS32 colonization. The results showed that WS32-L could survive in the wheat rhizosphere for long periods and could expand into new zones following wheat root extension. Significant increases in seedling fresh and dry weight, root fresh and dry weight, root surface area, number of root tips, and phosphorus accumulation in the wheat leaves occurred in response to WS32 rhizosphere colonization. RNA-seq analysis showed that a total of 1485 genes in wheat roots were differentially expressed between the inoculated conditions and the uninoculated conditions. Most of the transcriptional changes occurred for genes annotated to the following functional categories: "phosphorus and other nutrient transport," "hormone metabolism and organic acid secretion," "flavonoid signal recognition," "membrane transport," and "transcription factor regulation." These results are therefore valuable to future studies focused on the molecular mechanisms underlying the growth-promoting activities of PGPR on their host plants.

An Update of Lectins from Marine Organisms: Characterization, Extraction Methodology, and Potential Biofunctional Applications

Lectins are a unique group of nonimmune carbohydrate-binding proteins or glycoproteins that exhibit specific and reversible carbohydrate-binding activity in a non-catalytic manner. Lectins have diverse sources and are classified according to their origins, such as plant lectins, animal lectins, and fish lectins. Marine organisms including fish, crustaceans, and mollusks produce a myriad of lectins, including rhamnose binding lectins (RBL), fucose-binding lectins (FTL), mannose-binding lectin, galectins, galactose binding lectins, and C-type lectins. The widely used method of extracting lectins from marine samples is a simple two-step process employing a polar salt solution and purification by column chromatography. Lectins exert several immunomodulatory functions, including pathogen recognition, inflammatory reactions, participating in various hemocyte functions (e.g., agglutination), phagocytic reactions, among others. Lectins can also control cell proliferation, protein folding, RNA splicing, and trafficking of molecules. Due to their reported biological and pharmaceutical activities, lectins have attracted the attention of scientists and industries (i.e., food, biomedical, and pharmaceutical industries). Therefore, this review aims to update current information on lectins from marine organisms, their characterization, extraction, and biofunctionalities.

Expression of Pinellia pedatisecta Agglutinin PPA Gene in Transgenic Sugarcane Led to Stomata Patterning Change and Resistance to Sugarcane Woolly Aphid, Ceratovacuna lanigera Zehntner

The sugarcane woolly aphid is one of the main pests of sugarcane worldwide. The Pinellia pedatisecta agglutinin (PPA) gene has been demonstrated to function towards aphid resistance in other crops. In our study, in order to investigate the PPA function towards aphid control in sugarcane and its underlying mechanism, the PPA gene was overexpressed in a sugarcane Zhongzhe 1 (ZZ1) cultivar in independent transgenic sugarcane lines. It was confirmed in this study that PPA transgenic sugarcane can resist aphids via detecting the aphids’ development and tracing the survival number on PPA−transgenic sugarcane lines as well as PPA negative control lines. The mechanism of PPA lectin−associated defense against aphids was preliminarily explored. Stomatal patterning differences of sugarcane leaves between PPA−transgenic sugarcane lines and negative control lines were found. PPA overexpression led to an increase in stomata number and a decrease in stomata size that might have changed the transpiration status, which is critical for aphids’ passive feeding. Moreover, the antioxidant enzyme, sugar, tannin and chlorophyll content in sugarcane leaves before and after aphid infestation was determined. The results indicated that PPA overexpression in sugarcane resulted in an increase in antioxidant enzyme activity and tannin content, as well as a reduction in the decline of certain sugars. These together may improve sugarcane resistance against the sugarcane woolly aphid.

Review: The multiple roles of plant lectins

For decades, the biological roles of plant lectins remained obscure and subject to speculation. With the advent of technological and scientific progress, researchers have compiled a vast amount of information regarding the structure, biological activities and functionality of hundreds of plant lectins. Data mining of genomes and transcriptome sequencing and high-throughput analyses have resulted in new insights. This review aims to provide an overview of what is presently known about plant lectins, highlighting their versatility and the importance of plant lectins for a multitude of biological processes, such as plant development, immunity, stress signaling and regulation of gene expression. Though lectins primarily act as readers of the glycocode, the multiple roles of plant lectins suggest that their functionality goes beyond carbohydrate-recognition.

Purification and characterization of a highly thermostable GlcNAc-binding lectin from Collaea speciosa seeds

Lectins from plants of the Diocleinae subtribe often exhibit specificity towards mannose/glucose and derived sugars, with some plants also displaying a second lectin specific to lactose/GalNAc. Here, we present a novel lectin from Collaea speciosa, named CsL, that displays specificity for GlcNAc/glucose. The lectin was extracted from Collaea speciosa seeds and purified by a single chromatographic step on a Sephadex G-50 matrix. In solution, the lectin appears as a dimeric protein composed of 25 kDa monomers. The protein is stable at pH 7-8 and dependent on divalent cations. CsL maintained its agglutination activity after heating to 90 °C for 1 h. Glycan array studies revealed that CsL binds to N-glycans with terminal GlcNAc residues, chitobiose and chitotriose moieties. The partial amino acid sequence of the lectin is similar to that of some lactose-specific lectins from the same subtribe. In contrast to other ConA-like lectins, CsL is not toxic to Artemia. Because of its remarkably different properties and specificity, this lectin could be the first member of a new group inside the Diocleinae lectins.

Plant lectins and their many roles: Carbohydrate-binding and beyond

Lectins are ubiquitous proteins that reversibly bind to specific carbohydrates and, thus, serve as readers of the sugar code. In photosynthetic organisms, lectin family proteins play important roles in capturing and releasing photosynthates via an endogenous lectin cycle. Often, lectin proteins consist of one or more lectin domains in combination with other types of domains. This structural diversity of lectins is the basis for their current classification, which is consistent with their diverse functions in cell signaling associated with growth and development, as well as in the plant's response to biotic, symbiotic, and abiotic stimuli. Furthermore, the lectin family shows evolutionary expansion that has distinct clade-specific signatures. Although the function(s) of many plant lectin family genes are unknown, studies in the model plant Arabidopsis thaliana have provided insights into their diverse roles. Here, we have used a biocuration approach rooted in the critical review of scientific literature and information available in the public genomic databases to summarize the expression, localization, and known functions of lectins in Arabidopsis. A better understanding of the structure and function of lectins is expected to aid in improving agricultural productivity through the manipulation of candidate genes for breeding climate-resilient crops, or by regulating metabolic pathways by applications of plant growth regulators.

Perturbing dimer interactions and allosteric communication modulates the immunosuppressive activity of human galectin-7

The design of allosteric modulators to control protein function is a key objective in drug discovery programs. Altering functionally essential allosteric residue networks provides unique protein family subtype specificity, minimizes unwanted off-target effects, and helps avert resistance acquisition typically plaguing drugs that target orthosteric sites. In this work, we used protein engineering and dimer interface mutations to positively and negatively modulate the immunosuppressive activity of the proapoptotic human galectin-7 (GAL-7). Using the PoPMuSiC and BeAtMuSiC algorithms, mutational sites and residue identity were computationally probed and predicted to either alter or stabilize the GAL-7 dimer interface. By designing a covalent disulfide bridge between protomers to control homodimer strength and stability, we demonstrate the importance of dimer interface perturbations on the allosteric network bridging the two opposite glycan-binding sites on GAL-7, resulting in control of induced apoptosis in Jurkat T cells. Molecular investigation of G16X GAL-7 variants using X-ray crystallography, biophysical, and computational characterization illuminates residues involved in dimer stability and allosteric communication, along with discrete long-range dynamic behaviors involving loops 1, 3, and 5. We show that perturbing the protein-protein interface between GAL-7 protomers can modulate its biological function, even when the overall structure and ligand-binding affinity remains unaltered. This study highlights new avenues for the design of galectin-specific modulators influencing both glycan-dependent and glycan-independent interactions.

Lectins: Biological significance to biotechnological application

Lectins are a set of non-enzymatic carbohydrate binding proteins appearing in all domains of life. They function to recognize, interact and bring about reversible binding of a specific sugar moiety present in a molecule. Since glycans are ubiquitous in nature and are an essential part of various biological process, the lectins are been investigated to understand the profile of these versatile but complex glycan molecule. The knowledge gained can be used to explore and streamline the various mechanisms involving glycans and their conjugates. Thus, lectins have gained importance in carbohydrate-protein interactions contributing to the development in the field of glycobiology. This has led to a deeper understanding of the importance of saccharide recognition in life. Since their discovery, the lectins have become a great choice of research in the field of glycobiology and their biological significances have recently received considerable attention in the biocontrol field as well as medical sectors.

Dual Function Antimicrobial Loaded Lectin Carrier: A Strategy to Overcome Biomolecular Interference without Detectable Resistance

The disposition of a drug in a biological system may be altered by complex biological fluids; especially, protein binding to drugs influences their activity. Herein, we demonstrated a convenient method involving the noncovalent formulation of butea monosperma seed lectin (BMSL) with an antimicrobial lipid, cationic N-acylethanolamine (cNAE) to mitigate the serum protein interference. Fluorescence spectroscopy and molecular docking study revealed that cNAEs readily formed noncovalent complexes with serum protein, bovine serum albumin. The resulting complexes interfered with the antimicrobial activity of cNAEs. Strikingly, the noncovalent conjugates developed with BMSL and cNAEs (BcNAE) overcame the interference from serum protein and displayed remarkable antimicrobial activity against uropathogenic Escherichia coli (UPEC). Strikingly, the minimum inhibitory concentration (MIC) of the lectin conjugates (7.81 μM) was 4-fold lower than the MIC of pure cNAE. Mechanistic studies showed that BcNAE depolarized the bacterial membrane and affected the integrity to exert the antimicrobial activity. The membrane directed activities of BcNAE on UPEC efficiently eliminated the development of resistance even after 25 passages. The hemocompatibility results and the biosafety assessed in a zebrafish model suggested that BcNAE was nontoxic with good selectivity to bacteria. While testing the therapeutic efficacy against UPEC infected zebrafish, we found that 1× MIC cNAE is ineffective due to interference from biological fluids, which is in agreement with in vitro studies. Remarkably, the infected fish treated with 1× MIC BcNAE conjugates were rescued from infection and restored to the normal life in less than 9 h. Bacterial colony count assay revealed that BcNAE was more efficient in overcoming the biological fluid interference and eliminated the bacterial burden in infected zebrafish. Histopathology analysis supported that BcNAE treatment restored the pathological changes induced by UPEC and, thus, increased survival. The high antimicrobial intensity with limited chance for resistance development and potential to overcome biomolecular interference with a lack of toxicity enhance the merits of exploring lectin conjugates against infectious pathogens.

Systemic propagation of immunity in plants

Systemic immunity triggered by local plant-microbe interactions is studied as systemic acquired resistance (SAR) or induced systemic resistance (ISR) depending on the site of induction and the lifestyle of the inducing microorganism. SAR is induced by pathogens interacting with leaves, whereas ISR is induced by beneficial microbes interacting with roots. Although salicylic acid (SA) is a central component of SAR, additional signals exclusively promote systemic and not local immunity. These signals cooperate in SAR- and possibly also ISR-associated signaling networks that regulate systemic immunity. The non-SA SAR pathway is driven by pipecolic acid or its presumed bioactive derivative N-hydroxy-pipecolic acid. This pathway further regulates inter-plant defense propagation through volatile organic compounds that are emitted by SAR-induced plants and recognized as defense cues by neighboring plants. Both SAR and ISR influence phytohormone crosstalk towards enhanced defense against pathogens, which at the same time affects the composition of the plant microbiome. This potentially leads to further changes in plant defense, plant-microbe, and plant-plant interactions. Therefore, we propose that such inter-organismic interactions could be combined in potentially highly effective plant protection strategies.

Shrimp lectin (Md-Lec) conjugated copper sulfide nanoparticles enhance the elimination of aquatic pathogens in infected Nile tilapia (Oreochromis niloticus)

Lectins are known for their ability to bind to cell surface glycans, and are useful to develop a glycan-targeted drug delivery system. This study aimed to evaluate the capacity of pectin capped copper sulfide nanoparticles (pCuS NPs) to modulate the antibacterial activity of a lectin, Md-Lec, purified from the shrimp, Metapenaeus dobsoni. Fluorescence spectroscopy revealed that Md-Lec has the ability to form a complex with pCuS NPs. Haemagglutination assay showed that the carbohydrate binding site of the lectin was preserved even after complexing with pCuS. The minimum inhibitory concentrations (MICs) obtained for Md-Lec and pCuS NPs against the tested aquatic pathogens were 50 μg ml⁻¹ and 12.5 μM, respectively. Interestingly, the MIC of Md-Lec–pCuS NPs complex was four fold lower than that of pCuS, which was attributed to the bacterial cell surface glycan recognization activity of Md-Lec. Zone of inhibition assay showed that the zone size was highest for the lectin conjugated nanoparticles. Mechanistic study revealed that Md-Lec–pCuS NPs affect the bacterial membrane integrity and produce a large volume of reactive oxygen species to kill the bacteria. The practical aspect of using this lectin–pCuS NPs complex was evaluated by treating bacteria infected Nile tilapia (Oreochromis niloticus). The bacterial load was much less in the lectin–pCus NPs complex treated fish; moreover, the fish fully recovered from the infection. It was concluded that the conjugate of antibacterial lectin and NPs is more effective than the individual components.

Synthesis of Md-Lec-pCuSNPs and its enhanced in vitro and in vivo antibacterial activity.

Binding of a Soluble meso-Tetraarylporphyrin to Human Galectin-7 Induces Oligomerization and Modulates Its Pro-Apoptotic Activity

The selective targeting of protein-protein interactions remains a significant determinant for the proper modulation and regulation of cell apoptosis. Prototypic galectins such as human galectin-7 (GAL-7) are characterized by their ability to form homodimers that control the molecular fate of a cell by mediating subtle yet critical glycan-dependent interactions between pro- and anti-apoptotic molecular partners. Altering the structural architecture of GAL-7 can therefore result in resistance to apoptosis in various human cancer cells, further illustrating its importance in cell survival. In this study, we used a combination of biophysical and cellular assays to illustrate that binding of a water-soluble meso-tetraarylporphyrin molecule to GAL-7 induces protein oligomerization and modulation of GAL-7-induced apoptosis in human Jurkat T cells. Our results suggest that the integrity of the GAL-7 homodimer architecture is essential for its molecular function, in addition to providing an interesting porphyrin binding modulator for controlling apoptosis in mammalian cells.

Reviewing Mimosoideae lectins: A group of under explored legume lectins

Lectins are proteins capable of specific and reversible binding to mono- and/or oligosaccharides, and within this group, Legume lectins are the most studied. However, most of these studies focus on the Papilionoideae subfamily, with Caesalpinioideae and Mimosoideae lectins being significantly less explored in the literature. The Mimosoideae subfamily consists of at least 79 genera and 3275 species, but, to date, only about 14 lectins have been purified, a fact which shows the lack of studies for this group. Based on their purification protocols, as well as physicochemical and structural properties, Mimosoideae lectins are very heterogeneous. Despite the few studies, a wide variety of biological activities have been tested, including, for example, inflammatory, anticancer, antibacterial, and antifungal. In this context, the present review aims to summarize the available data regarding the purification, physicochemical and structural properties, as well as biological activities, of lectins extracted from plants of the Mimosoideae subfamily in order to bring more insight to researchers interested in further exploring the potential of these molecules.

Purification and partial characterization of a new lectin from Parkia panurensis Benth. ex H.C. Hopkins seeds (Leguminosae family; Mimosoideae subfamily) and evaluation of its biological effects

Lectins are proteins that have as one of their main characteristics recognizing and reversibly binding to carbohydrates. In this work, it was possible to purify and characterize a lectin from Parkia panurensis (Leguminosae family; Mimosoideae subfamily) seeds by a combination of the techniques: protein precipitation, along with affinity and then ion exchange chromatography using the Sepharose-mannose and diethylaminoethyl matrices, respectively. The pure lectin, called PpaL, has affinity by D-mannose, D-glucose and derivatives. PpaL was stable over a wide range of temperature and pH, and it showed an SDS-PAGE profile of only one protein band with apparent mass of 45 kDa, subsequently confirmed by mass spectrometry, and presented a molecular mass of 50,566 ± 1 Da. PAGE analysis and molecular exclusion chromatography demonstrated that PpaL is presented as a dimer in solution. Partial sequencing of the primary structure resulted in a total of 334 amino acid residues with approximately 97% similarity to Parkia biglobosa and Parkia platycephala seed lectins. PpaL was shown to be toxic against Artemia nauplii and had an LC₅₀ of 20 µg/mL. The effects of biological activities presented by these proteins make them important biotechnological tools, demonstrating the importance of bioprospection of new lectins.

A molecularly engineered antiviral banana lectin inhibits fusion and is efficacious against influenza virus infection in vivo

There is a strong need for a new broad-spectrum antiinfluenza therapeutic, as vaccination and existing treatments are only moderately effective. We previously engineered a lectin, H84T banana lectin (H84T), to retain broad-spectrum activity against multiple influenza strains, including pandemic and avian, while largely eliminating the potentially harmful mitogenicity of the parent compound. The amino acid mutation at position 84 from histidine to threonine minimizes the mitogenicity of the wild-type lectin while maintaining antiinfluenza activity in vitro. We now report that in a lethal mouse model H84T is indeed nonmitogenic, and both early and delayed therapeutic administration of H84T intraperitoneally are highly protective, as is H84T administered subcutaneously. Mechanistically, attachment, which we anticipated to be inhibited by H84T, was only somewhat decreased by the lectin. Instead, H84T is internalized into the late endosomal/lysosomal compartment and inhibits virus-endosome fusion. These studies reveal that H84T is efficacious against influenza virus in vivo, and that the loss of mitogenicity seen previously in tissue culture is also seen in vivo, underscoring the potential utility of H84T as a broad-spectrum antiinfluenza agent.

Dual function of lectins — new perspectives in targeted photodynamic therapy

Porphyrins and phthalocyanines are photosensitizers (PS) that are used in clinical imaging, detection of cancer cells and are particularly applied in photodynamic therapy (PDT). Many scientists have been focused on the design of different porphyrin compounds. However, similar to other anti-cancer agents, they cannot selectively recognize tumor tissues. Scientists are seeking new methods to overcome this problem and to find appropriate targeted delivery strategies. Plant lectins are especially suitable molecules for such targeting as they preferentially recognize specific antigens on the glycosylated cancer cells. This review will give more detailed information about the dual function of lectins and their interactions with PSs, which is a new perspective in targeted PDT. The implications and potential applications of such studies will also be discussed.

ArtinM: Purification and Evaluation of Biological Activities

The immunomodulatory activity of plant lectins has been evaluated because of their high selectivity for glycans linked to receptors on innate and adaptative immune cells. ArtinM is a mannosyl-binding lectin, obtained from the seeds of Artocarpus heterophyllus, that induces the differentiation of CD4⁺ T cells and macrophages by interacting with CD3 and TLR2/CD14, respectively. This ArtinM property ultimately favors the combat of intracellular pathogens, opening new perspectives on the lectins application as immunomodulatory agents. The current section describes protocols for purification and evaluation of ArtinM biological activity. The purification is based on the ArtinM-D-mannose affinity. The effect of inducing IL-12 production by murine macrophages cell line is adopted to evaluate the ArtinM biological activity.

Lectins as possible tools for improved urinary bladder cancer management

Urinary bladder cancer is the ninth most common cancer in developed countries with poor prognosis and outcome for the patient due to the challenging diagnosis and limited treatment possibilities. Bladder cancer arises mainly from urothelial cells lining the lumen. Urothelial cells form a three- to five-layered urothelium, which maintains the blood-urine barrier. The carbohydrates that cover the apical surface of superficial urothelial cells, i.e. umbrella cells, are crucial for this function. The composition of the carbohydrate covering is altered during urothelial cancer transformation. These bladder cancer-associated carbohydrate changes are a promising field for diagnosis, therapy and management. Lectins, which are carbohydrate-binding proteins, can be used to detect subtle alterations in carbohydrate composition during urothelial cancer transformation. Extensive research into various lectin applications has already been conducted, but the results are often contradictory and confusing. None of these applications have reached clinical trials. We review the literature and discuss (i) current bladder cancer management, (ii) lectin-based assays for detection of various cancer subtypes, (iii) lectin-based strategies for innovative bladder cancer treatment and finally (iv) lectins in nanotheranostics for personalized bladder cancer management.

Glycoanalysis of the placental membrane glycoproteins throughout placental development

Structural changes of glycans are observed in different (patho)physiological conditions. Human placental membrane (glyco)proteins were isolated from the first and third trimester placentas of mothers at different ages. By using lectin microarray, we demonstrated that the placental membrane N-glycome contains several N-glycan groups: high mannose, asialylated and sialylated biantennary moieties, bisected, core fucosylated, fucosylated at other positions (bearing terminal and/or antennary Fuc), α2-6 and α2-3 sialylated structures. Employing MALDI-TOF MS enabled identification of over sixty different N-glycan structures in all samples, with 17 moieties exceeding the relative abundance of 2%. The major MS peaks originated from: 1) biantennary complex type N-glycan with a bisecting GlcNAc residue and 2) a core Fuc paucimannosidic and high mannose type structures M3-M9. Age of mothers and the stage of placental development affected N-glycome. The work presented in this article is the first comprehensive mass spectrometric study of the N-glycome of human placental membrane proteins. Our results may be seen as the baseline which can serve for future MALDI MS profiling of the placental membrane N-glycome in different pathophysiological conditions.

Remarkable Effect of Jacalin in Diminishing the Protein Corona Interference in the Antibacterial Activity of Pectin-Capped Copper Sulfide Nanoparticles

Herein, we report a new strategy based on jacalin functionalization to diminish the impact of biological fluids in the antibacterial applications of nanoparticles (NPs). Precoating pectin-capped copper sulfide NPs (pCuS) with bovine serum albumin produced a protein corona, which affects the antibacterial activity of pCuS. It was found that the minimum inhibitory concentration (MIC) increases fourfold because of the formation of the protein corona. Interestingly, the pCuS functionalized with jacalin enhance the targeting capabilities through bacterial cell surface glycan recognition with no interference from the protein corona. The MIC of pCuS decreases 16-fold on functionalization with jacalin. Mechanistic studies indicated that the pCuS functionalized with jacalin impede the protein corona interference and induce bacterial cell death by impairing the GSH/reactive oxygen species balance and disrupting the bacteria cell membrane. As a proof of concept, we used a bacteria-infected zebrafish animal model to demonstrate the interference of biological fluids in the antibacterial activity of NPs. Infected zebrafish treated with 1× MIC of pCuS failed to recover from the infection, but 4× MIC rescues the fish. The requirement of a high dose of NPs to treat the infection confirms the interference of biological fluids in nanotherapeutic applications. At the same time, the jacalin-pCuS complex rescues the infected fish at 16-fold lesser MIC. The results obtained from this study suggest that jacalin-mediated NP targeting may have broad implications in the development of future nanomedicine.

Sequence-Defined Introduction of Hydrophobic Motifs and Effects in Lectin Binding of Precision Glycomacromolecules

This study investigates the influence of an increasingly hydrophobic backbone of multivalent glycomimetics based on sequence-defined oligo(amidoamines) on their resulting affinity toward bacterial lectins. Glycomacromolecules are obtained by stepwise assembly of tailor-made building blocks on solid support, using both hydrophobic aliphatic and aromatic building blocks to enable a gradual change in hydrophobicity of the backbone. Their binding behavior toward model lectin Concanavalin A (ConA) is evaluated using isothermal titration calorimetry (ITC) and surface plasmon resonance (SPR) showing higher affinities for glycomacromolecules with higher content of hydrophobic and aromatic moieties in the backbone. Finally, glycomacromolecules are tested in a bacterial adhesion inhibition study against Escherichia coli where more hydrophobic backbones yield higher inhibitory potentials most likely due to additional secondary interactions with hydrophobic regions of the protein receptor as well as a change in conformation exposing carbohydrate ligands for increased binding. Overall, the results highlight the influence and thereby importance of the polymer backbone itself on the resulting properties of polymeric biomimetics.

Comparative transcriptome analysis of soybean response to bean pyralid larvae

BACKGROUND

Soybean is one of most important oilseed crop worldwide, however, its production is often limited by many insect pests. Bean pyralid is one of the major soybean leaf-feeding insects in China. To explore the defense mechanisms of soybean resistance to bean pyralid, the comparative transcriptome sequencing was completed between the leaves infested with bean pyralid larvae and no worm of soybean (Gantai-2-2 and Wan82-178) on the Illumina HiSeq™ 2000 platform.

RESULTS

In total, we identified 1744 differentially expressed genes (DEGs) in the leaves of Gantai-2-2 (1064) and Wan82-178 (680) fed by bean pyralid for 48 h, compared to 0 h. Interestingly, 315 DEGs were shared by Gantai-2-2 and Wan82-178, while 749 and 365 DEGs specifically identified in Gantai-2-2 and Wan82-178, respectively. When comparing Gantai-2-2 with Wan82-178, 605 DEGs were identified at 0 h feeding, and 468 DEGs were identified at 48 h feeding. Gene Ontology (GO) annotation analysis revealed that the DEGs were mainly involved in the metabolic process, single-organism process, cellular process, responses to stimulus, catalytic activities and binding. Pathway analysis showed that most of the DEGs were associated with the plant-pathogen interaction, phenylpropanoid biosynthesis, phenylalanine metabolism, flavonoid biosynthesis, peroxisome, plant hormone signal transduction, terpenoid backbone biosynthesis, and so on. Finally, we used qRT-PCR to validate the expression patterns of several genes and the results showed an excellent agreement with deep sequencing.

CONCLUSIONS

According to the comparative transcriptome analysis results and related literature reports, we concluded that the response to bean pyralid feeding might be related to the disturbed functions and metabolism pathways of some key DEGs, such as DEGs involved in the ROS removal system, plant hormone metabolism, intracellular signal transduction pathways, secondary metabolism, transcription factors, biotic and abiotic stresses. We speculated that these genes may have played an important role in synthesizing substances to resist insect attacks in soybean. Our results provide a valuable resource of soybean defense genes that will benefit other studies in this field.

Targeting the Immune System with Plant Lectins to Combat Microbial Infections

The arsenal of drugs available to treat infections caused by eukaryotic and prokaryotic microbes has been declining exponentially due to antimicrobial resistance phenomenon, leading to an urgent need to develop new therapeutic strategies. Host-directed immunotherapy has been reported as an attractive option to treat microbial infections. It consists in the improvement of host defenses by increasing the expression of inflammatory mediators and/or controlling of inflammation-induced tissue injury. Although the in vitro antimicrobial and immunomodulatory activities of lectins have been extensively demonstrated, few studies have evaluated their in vivo effects on experimental models of infections. This review aims to highlight the experimental use of immunomodulatory plant lectins to improve the host immune response against microbial infections. Lectins have been used in vivo both prophylactically and therapeutically resulting in the increased survival of mice under microbial challenge. Other studies successfully demonstrated that lectins could be used in combination with parasite antigens in order to induce a more efficient immunization. Therefore, these plant lectins represent new candidates for management of microbial infections. Furthermore, immunotherapeutic studies have improved our knowledge about the mechanisms involved in host–pathogen interactions, and may also help in the discovery of new drug targets.

Plant Lectins Targeting O-Glycans at the Cell Surface as Tools for Cancer Diagnosis, Prognosis and Therapy

Aberrant O-glycans expressed at the surface of cancer cells consist of membrane-tethered glycoproteins (T and Tn antigens) and glycolipids (Lewis a, Lewis x and Forssman antigens). All of these O-glycans have been identified as glyco-markers of interest for the diagnosis and the prognosis of cancer diseases. These epitopes are specifically detected using T/Tn-specific lectins isolated from various plants such as jacalin from Artocarpus integrifola, and fungi such as the Agaricus bisporus lectin. These lectins accommodate T/Tn antigens at the monosaccharide-binding site; residues located in the surrounding extended binding-site of the lectins often participate in the binding of more extended epitopes. Depending on the shape and size of the extended carbohydrate-binding site, their fine sugar-binding specificity towards complex O-glycans readily differs from one lectin to another, resulting in a great diversity in their sugar-recognition capacity. T/Tn-specific lectins have been extensively used for the histochemical detection of cancer cells in biopsies and for the follow up of the cancer progression and evolution. T/Tn-specific lectins also induce a caspase-dependent apoptosis in cancer cells, often associated with a more or less severe inhibition of proliferation. Moreover, they provide another potential source of molecules adapted to the building of photosensitizer-conjugates allowing a specific targeting to cancer cells, for the photodynamic treatment of tumors.

Glycoproteins functionalized natural and synthetic polymers for prospective biomedical applications: A review

Glycoproteins have multidimensional properties such as biodegradability, biocompatibility, non-toxicity, antimicrobial and adsorption properties; therefore, they have wide range of applications. They are blended with different polymers such as chitosan, carboxymethyl cellulose (CMC), polyvinyl pyrrolidone (PVP), polycaprolactone (PCL), heparin, polystyrene fluorescent nanoparticles (PS-NPs) and carboxyl pullulan (PC) to improve their properties like thermal stability, mechanical properties, resistance to pH, chemical stability and toughness. Considering the versatile charateristics of glycoprotein based polymers, this review sheds light on synthesis and characterization of blends and composites of glycoproteins, with natural and synthetic polymers and their potential applications in biomedical field such as drug delivery system, insulin delivery, antimicrobial wound dressing uses, targeting of cancer cells, development of anticancer vaccines, development of new biopolymers, glycoproteome research, food product and detection of dengue glycoproteins. All the technical scientific issues have been addressed; highlighting the recent advancement.