Sundaram Janarthanan

Lectins are made with identical polypeptide subunits as homo-oligomers in various species of Canavalia. Their interaction with the structures of specific glycans is influenced greatly when many identical polypeptides are cooperatively involved in a homo-oligomeric state than when they interact as individual polypeptide subunits. In the present study, lectins characterised from various species of Canavalia available in the literature were identified, and their sequences were retrieved to conduct in-silico bioinformatic analyses to offer a structural insight into their interaction with specific glycans such as D-mannose and. D-glucose. Our results disclosed that one of the critical parameters on the characteristic feature of lectins, i.e. the number of amino acids contributing to carbohydrate recognition domains (CRD) by lectin homo-oligomers in their tertiary and quaternary conformations through. in-silico docking, was less than in reported experimental studies conducted using XRD. Further, the docking results revealed that the kind of amino acids involved in recognising the structures of glycans was significantly different among homo-oligomeric polypeptide chains of various lectins, indicating the unique nature of each protein in their functions. The nature of glycan binding by these lectins was observed with higher affinity scores, with their quaternary structures containing four homo-oligomeric polypeptide chains. It is thus recognised that the unique nature of homo-oligomers of lectins from various species of Canavalia that possess analogous structural features relies profoundly on the kind of amino acid residues for their interaction with glycans in accomplishing their diverse functions.

Lectins, the glycan‐binding proteins that are known to function as essential pattern‐recognition receptors (PRRs) in the innate immune system of insects, also act as strategic modulators of physiological stress responses. An attempt is made here to demonstrate how chronic stress affects the lectin from the larvae of Zophobas morio , an adapter molecule in physiological response. The haemagglutination (HA) titer used to measure the activity of lectin revealed discrepancies in the larval serum of Z. morio after exposure to various stress conditions. Among the stress‐induced treatment groups, except the control, the treatments exhibited a marked reduction in the HA activity from the larval serum of Z. morio . Examination of the haemagglutination inhibition (HAI) activity, which is used to assess the ability of specific sugars that inhibit this process, clearly showed that lectin from the larval serum of stress‐induced groups had deteriorated in its binding ability to d ‐fucose and lactose. Pyriproxyfen (a juvenile hormone analog) mimics hormones exclusive to insects and is extremely target‐specific. It induces physiological and cellular alterations in insects. Although the effects of pyriproxyfen on insect lectins are indirect, it acts through hormonal signaling to affect lectins. The relative quantitation of d ‐fucose‐binding lectin (FBL) mRNA under various stress conditions in the larval fat body of Z. morio , analyzed through RT‐qPCR, clearly indicated significantly lower levels of its expression, except for pyriproxyfen treatment. Molecular docking and simulation were performed to recognize the stability of the interaction between FBL and pyriproxyfen. These results revealed a significant binding characterized by high affinity through a strong amide bridge, and other non‐covalent interactions, showing evidence for increased expression of lectin at doses of pyriproxyfen treatments as a measure of neutralization. On the whole, stressful environments bring swift and dynamic changes in the activity of lectin, including its expression in Z. morio larvae, revealing lectin as a vital constituent in response to physiological challenges.

Insects have evolved a wide range of innate immune responses as a result of the variety of substrates they consume and the settings in which they reside. For this reason, they represent a nearly limitless source of biologically active compounds that possess unparalleled applications. Of particular interest in our current review are the lectins, the key elements of membrane‐bound or extracellular pattern‐recognition receptors (PRRs). Lectins are proteins that specifically recognize and interact with glycans non‐covalently. Besides their crucial role in insect immunity, lectins are at the pinnacle of research owing to their prospective applications. This is attributed to their capacity to discern subtle variations in the cell surface carbohydrate structures that are crucial for protein‐carbohydrate recognition. This review focuses on emerging trends in research on insect lectins with the objective of emphasizing the significance of further investigation that can perhaps help in the exploration of their probable applications.

The enzyme phenoloxidase (PO) is an essential component in the immune system of insects, which is responsible for the rapid activation and encapsulation of microbial pathogens. This study focuses on the in vitro and in silico investigation of PO using 4th instar larvae of black soldier fly (BSF), Hermetia illucens. The preliminary assays confirmed the occurrence of PO in the H. illucens larval haemolymph with the highest affinity towards DL-dopa as the substrate within 5 min at a λmax of 480 nm. The relative quantification of the H. illucens PO (HiPO) gene in the larvae showed higher expression in the fat body (FB) compared to haemocyte lysate supernatant (HLS). The PO studied under control and stress-induced conditions showed decreased activity during starvation and increased activity during injury. In silico analysis using molecular docking of various substrates with the reference structure of PO showed the highest affinity towards DL-dopa and L-dopa, followed by tyrosine, dopamine, and catechol, respectively. Hemocyanin and tyrosinase as functional domains were observed in the amino acid sequence of HiPO with an N-glycosylation site. Molecular docking of HiPO revealed a strong affinity for DL-dopa, and molecular dynamics simulation studies for the HiPO-DL-dopa complex provided their functional insights. The findings offer biomedical applications by providing an insight into the innate immune mechanisms that can guide the development of novel antimicrobial, antioxidant, and immunomodulatory strategies. This would help to comprehend the relation between immunity and metabolism, positioning H. illucens as a resilient feed source that supports livestock health, maintaining food safety and quality.

In recent times, nanotechnology has evolved as a fast‐developing area with possible applications in numerous fields. There is a growing concern about the potential toxicity of nanoproducts to the environment and living organisms after considering the possible utilization of various kinds of nanomaterials in diverse areas of application. Subsequently, the toxicity of nanoparticles has been studied by employing several animal models to generate data to judge the judicious use of such valuable nanomaterials. Among various animal model systems used to investigate the toxicity of nanoparticles, insects are considered valuable models due to their well‐known genetics, shorter lifespan, sensitivity to environmental changes, etc. Most importantly, some of the insects as test models (e.g., Drosophila melanogaster ) could be very useful in predicting human toxicity, and therefore, it may be an opportunity to reduce the use of mammalian models. This review is intended to provide a comprehensive summary of the toxicity of nanoparticles in insect systems at the behavioral, morphological, physiological, and molecular levels. The overall analysis of the general literature survey made through this review showed the vulnerability of insects to the exposure of nanoparticles, emphasizing the need for comprehensive risk assessment strategies.

The expression of galectin-8 at various organs, its characterization through in silico analysis with possible anti-viral activity, was carried out from the grubs of Oryctes rhinoceros . Galectin-8 amplification, sequencing, prediction of amino acids, and analysis showed functional domains specific to galectin of several other species of insects. Further, quantification of galectin-8 transcripts revealed significantly higher levels of expression in hemocyte lysate than any other organs. The glycan lactose, that specifically inhibited the functional activity of galectin was used as a ligand for molecular docking, with a binding energy of -8.5 kcal/mol, revealing the specificity of lactose to galectin-8. MD simulation performed to find the binding stability disclosed the dynamic nature of galectin-8 and its targeted interaction with lactose. The protein-protein docking performed between galectin-8 with two dengue viral non-structural proteins, NS1 and NS5, suggested the possible antiviral property of galectin-8 against the dengue virus.