Protein and Peptide Letters最新文献

Introduction: Abelmoschus esculentus (okra) from the Malvaceae family is widely used in culinary applications and is reported to have many potential therapeutic effects attributed to the compounds isolated from it. In this work, we set out to explore its seed proteome for the isolation of lectins and characterize them Method: A protein of about 21kDa was isolated and purified using chromatography techniques from the ammonium sulphate crude protein extract. It was evaluated for hemagglutination activity on rabbit erythrocyte suspension, trypsin inhibitory activity using chemical assay, and evaluation of anti-cancer activity using cell lines. Mass and transcriptome analysis were done to deduce the complete sequence of the isolated protein.

Results: Using functional, mass, and transcriptome analysis, the protein was identified as AEL (Abelmoschus esculentus lectin), which was reported earlier. Only a partial sequence of AEL was known, and in this work, we have deduced its complete sequence. It showed significant anti-- cancer activity against HeLa (cervical cancer) and T84 (colon cancer) with MIC (Minimum inhibitory concentration) of 20μg/ml and 40% and 30% reduction in cell viability at 100μg/ml and insignificant effect on ACHN (adenocarcinoma) cell lines. No significant effect was seen with the tested doses on normal control human cell lines HEK293 (human embryonic kidney cells). The purified protein shows specificity for lactose and galactose in the hemagglutination assay and trypsin inhibition activity.

Discussion: Studies of okra seed proteome lead to purification of AEL, a 21 kDa protein with dual hemagglutination activity and trypsin inhibitory activity. It showed potential anticancer activity in cervical, colon cancer cell lines and minimal effects on adenocarcinoma and control cell lines, suggesting specificity. The complete sequence of AEL was elucidated which will aid in its bioinformatics analysis, was isolated from okra seeds.

Conclusion: There are very few reported dual-acting lectins with potential anticancer activity, and this work will help understand their mechanistic interactions better.

Introduction: Mycobacterium tuberculosis (Mtb) is a Gram-positive bacterium that causes tuberculosis (TB). It remains viable for extended periods within host macrophages by entering a dormant state. Alpha crystallin 1 (Acr1) is a 16 kDa protein of Mtb and is reported to be highly upregulated in latent TB. Acr1 suppresses the host's immune system by impairing the differentiation and maturation of dendritic cells and macrophages. We hypothesize that Mtb judiciously utilizes its Acr1 protein to paralyse the immune system of the host by inducing the release of IL-10 and generating an immunosuppressive environment.

Methods: We employed in silico tools to identify highly promiscuous, IL-10-inducing and IL-6- non-inducing epitopes of Mtb. Moreover, the selected epitope was synthesized and tested for its suppressive activity and generation of Tregs.

Results: We identified the presence of a specific epitope in Acr1 (F18) that is responsible for bolstering the release of IL-10 and Tregs through in silico tools and verified the activity by in vitro assays. In hPBMCs, the F18 epitope could suppress the proliferation of CD4 T cells stimulated with PHA and expand the pool of Tregs in a dose-dependent manner.

Discussion: The F18 epitope from Mtb's Acr1 protein promotes IL-10 and Treg responses without triggering pro-inflammatory IL-6, suggesting a potential immunoregulatory role. While it holds potential for treating autoimmune diseases, its impact on infection tolerance in tuberculosis should be further investigated.

Conclusion: Our findings suggest that the F18 epitope induces IL-10 production and Treg differentiation while inhibiting CD4+ T cell proliferation and IL-6 secretion, thereby promoting an immunosuppressive environment. Furthermore, this study highlights the potential of Acr1 and its immunosuppressive epitope F18 as therapeutic agents for inducing suppressive Tregs in the management of autoimmune diseases.

Recombinant proteins, which are produced using recombinant DNA technology, have transformed the domains of biotechnology and biomedicine by allowing the production of proteins that are often expensive or difficult to obtain from natural sources. More than 130 recombinant proteins are currently in clinical use by the US FDA, demonstrating the importance of these proteins in both research and therapeutic applications. Bacterial, yeast, mammalian cell cultures, and hybridoma technology are examples of recombinant protein production systems that have enabled the large-scale production of therapeutic proteins, including monoclonal antibodies, which are now essential tools in disease treatment. From their origins with human insulin in the 1980s to the most recent developments in third-generation proteins, this brief review examines the development of recombinant protein therapies. The first generation concentrated on natural structures; the second generation focused on enhancing safety, pharmacokinetics, and specificity; and the third generation is ready to present innovative formulations and delivery systems. This review also covers the use of recombinant proteins in cancer treatment, different protein production systems, and design techniques that keep improving the safety and effectiveness profiles of protein therapies.

Background: The increasing resistance of fungal pathogens to conventional antifungal treatments has led to a global rise in fungal infections, affecting human health (Candida spp.) and agricultural productivity (Colletotrichum and Fusarium spp.). Antimicrobial peptides (AMPs), such as defensins, have gained attention for their potential in controlling these infections due to their broad-spectrum activity.

Objectives: The aim of this study was to partially purify and characterize the antifungal activity of a defensin-enriched fraction (F3) from Capsicum chinense fruits. Specifically, we sought to evaluate its efficacy against pathogenic fungi and yeasts, and to assess the relative abundance of defensins in the fraction.

Methods: The F3 fraction was obtained using ion exchange and molecular exclusion chromatography. Reverse-phase chromatography (HPLC) was then employed for further purification. The antifungal activity of F3 was tested against Colletotrichum, Fusarium, and Candida species. Mass spectrometry was used to identify and characterize the defensin (CcDef3) within the fraction. The presence of the defensin relative to other components was inferred from electrophoretic profiles and peptide analysis.

Results: The F3 fraction exhibited significant antifungal activity, with growth inhibition of Colletotrichum lindemuthianum of 51% and 60.9% at concentrations of 100 and 200 μg mL-1, respectively. The fraction also inhibited the growth of several Candida species, notably C. nivariensis (93.8%) and C. bracarensis (79.6%) at 100 μg mL-1. Cell viability analysis indicated a fungistatic effect. Fluorescence microscopy assays showed that F3 induced membrane permeabilization in C. parapsilosis and C. lindemuthianum, and increased ROS production in C. pelliculosa and F. solani. The defensin-rich H8 fraction, containing a 6.5 kDa protein (CcDef3), was identified as a major component via mass spectrometry.

Conclusion: These results suggest that the F3 fraction, particularly the defensin CcDef3, has potential as an antifungal agent for biotechnological and therapeutic applications. However, further studies are needed to quantify the contribution of CcDef3 relative to other components in the fraction and to fully isolate the defensin for in-depth analysis.

Peptidases play crucial roles in numerous physiological processes within living organisms. Therefore, they have been employed in various pharmaceutical applications. Plant peptidases have attracted considerable attention in various areas due to their specificity, stability across a diverse range of pH and temperatures, and safety profile. Here, we have focused on the use of plant peptidases, mostly papain and bromelain, to produce biologically active peptides, which confer various health advantages, including antioxidant, antimicrobial, antihypertensive, analgesic, antidiabetic, and anti-inflammatory effects. We have also discussed the importance of the action mechanism of peptidases for generating bioactive peptides with specific sequences and functions, the ecological and sustainability benefits of plant-derived peptidases compared to animal alternatives, digestive stability and bioavailability of peptides, as well as some obstacles to the commercialization of bioactive peptides and key challenges in peptidase-based industrial applications. Finally, we have examined enzyme immobilization as a viable method to enhance the production of bioactive peptides, offering numerous advantages in both research and industry contexts.

The incidences of immune-related disorders have drastically increased in recent years across the world population. Treatment and management of these diseases, especially autoimmune disorders, are complex and challenging. Available synthetic drugs are not completely effective and also pose serious side effects for the patients. Cyclotides are a class of plant-derived cyclic peptides (28-37 amino acids) with three conserved disulfide linkages establishing a cyclic cystine knot (CCK) motif that makes them very stable biomolecules. Their inherent stability, bioavailability and membrane-penetrating capabilities render them attractive potential pharmacological agents. Studies have demonstrated that cyclotides can either enhance or suppress immune responses, making them versatile candidates for treating various immune-related disorders. Of more than 1000 cyclotides discovered to date, only up to 15 native cyclotides (e.g. kalata B1, pase and caripe cyclotides) have been screened to demonstrate their immunomodulatory activity. Of special significance is the chemically synthesised lysine mutant of kalata B1 viz. [T20K], where preclinical studies have shown promise in the treatment of the autoimmune disorder, multiple sclerosis. In vivo studies in mice models have demonstrated that daily administration of 1mg/day of [T20K] led to a significant decrease in the level of cytokine secretion, lesser demyelination (<1%) and very low inflammatory index (<0.5), in the immunized mice. Moreover, when compared with other immunosuppressive drugs (azathioprine, prednisolone, and cyclosporine A) there was a notable drop in mortality and morbidity in mice administered with [T20K]. The cyclotides, kalata B1 and MCoTI-I have also been used as scaffolds to graft bioactive peptides with immunomodulatory activity. Subsequent in vitro and in vivo studies of these grafted cyclotides have demonstrated their therapeutic ability. Keeping in view the therapeutic potential of cyclotides as immunomodulatory peptides, the present review discusses its current research scenario and implications for the future in tackling immune-related disorders.

Objective: This study aimed to explore whether excessive HIF2α can amplify the impact of human Umbilical Cord Mesenchymal Stem Cell-derived Extracellular Vesicles (hUC-MSC- EVs) on endothelial cells.

Methods: In this study, we created HIF2α-overexpressing hUC-MSC-EVs and compared their pro-angiogenic effects with control EVs on Human Umbilical Vein Endothelial Cells (HUVECs). MTT assay and Edu staining were used to detect the viability and proliferation ability of HUVECs, and Transwell and Tube Formation Assays were used to detect cell migration and tube formation ability. qPCR assay was used to detect the expression of cellular angiogenic markers. Subsequently, miRNAs that might be regulated by HIF2α were predicted by bioinformatics analysis, and qPCR was used to detect the relative expression of miRNAs in HUVECs treated with hUC-MSC- EV, which over-expresses HIF2α. Subsequently, miR-146a inhibitors were used to investigate the role of miR-146a in mediating the pro-angiogenic effect of HIF2α on HUVECs by detecting cell viability, proliferation, migration, tube-forming ability, and expression of angiogenic markers. Finally, AKT/ERK phosphorylation and Spred1 expression were detected using Western blotting.

Results: Our findings have indicated that overexpression of HIF2α significantly enhances the ability of hUC-MSC-EVs to stimulate proliferation, migration, and tube formation in HUVECs, as demonstrated by MTT/Edu staining, Transwell assay, and tube formation assay results, respectively. Mechanistically, excessive HIF2α has been found to induce the expression of miR-146a in HUVECs and the overexpression of a miR-146a inhibitor to negate the influence of excessive HIF2α on hUC-MSC-EV-induced activity in HUVECs.

Conclusion: The overexpression of HIF2α is an effective strategy for enhancing the pro-angiogenic function of hUC-MSC-EVs.

Introduction: Vigna unguiculata (Cowpea), a legume rich in phytochemicals, has been traditionally used to improve fertility and treat various ailments. This study used in-silico and invivo methods to evaluate the effects of cowpea protein isolate and essential oil on reproductive hormonal and antioxidant indices.

Methods: Forty (40) female rats were divided into eight groups (n=5). After 14 days of treatment, hormone levels (progesterone, prolactin, testosterone and estradiol) and antioxidant activities (superoxide dismutase (SOD), catalase (CAT) were assessed using biochemical kits and standard procedures. Molecular docking studies were performed using PyRx and Biovia Discovery Studio 2021. The ligands generated through gas chromatography-mass spectroscopy (GCMS) analysis of cowpea oil and the target proteins (SOD and CAT) were from downloaded PubChem and RCSB Protein Data Bank, respectively.

Results: The results of this study showed that cowpea essential oil and protein isolate significantly (p<0.05) reduced plasma CAT and SOD activities while increasing their activities in the ovary and liver tissues compared to the infertile untreated group. Consistent administration of either cowpea oil or protein isolate was observed to positively regulate the hormonal indices in the infertile treated groups. Phthalic acid, 2-cyclohexyl ethyl isobutyl ester demonstrated a strong binding affinity and binding constant with SOD and CAT, which suggests that the ligands from cowpea essential oil may have antioxidant and pro-fertility properties that could be developed to treat fertility- related issues.

Conclusion: Based on the results of this study, it can be concluded that V. unguiculata has antioxidant property, and can promote fertility, possibly through its rich embedded phytochemicals, which substantiates its traditional claim.

Athletes frequently encounter sleep deprivation due to the demands of high-intensity training and competition, which can significantly impair their physical recovery and athletic performance. α-Lactalbumin (α-LA), a key component of whey protein that is rich in tryptophan, has been shown to promote the synthesis of serotonin and melatonin, thereby regulating sleep cycles. Moreover, α-LA has demonstrated the ability to reduce inflammation and oxidative stress associated with fatigue and stress, further contributing to improved sleep quality. This review provides a critical evaluation of the current evidence supporting the role of α-LA in enhancing sleep quality in athletes through mechanisms such as neurotransmitter regulation, immune function improvement, and enhancement of antioxidant defenses. Additionally, it highlights the necessity for further research into the differential effects of α -LA on sleep across various sports and gender groups, as well as its potential synergistic interactions with other nutrients. These insights are essential for developing optimized nutritional interventions aimed at enhancing athletic performance.