Protein and Peptide Letters最新文献

Like other vertebrates, amphibians possess innate and adaptive immune systems. At the center of the adaptive immune system is the Major Histocompatibility Complex. The important molecules of innate immunity are antimicrobial peptides (AMPs). These peptides are secreted by granular glands in the skin and protect the animal against microorganisms entering its body through the skin. AMPs offer an effective and rapid defense against pathogenic microorganisms and have cationic and amphiphilic structures. These peptides are small gene-encoded molecules of 8-50 amino acid residues synthesized by ribosomes. These small molecules typically exhibit activity against bacteria, viruses, fungi, and even cancer cells. It is known that today's amphibian AMPs originated from a common precursor gene 150 million years ago and that the origin of these peptides is preprodermaseptins. Today, antibiotic resistance has occurred due to the incorrect use of antibiotics. Traditional antibiotics are becoming increasingly inadequate. AMPs are considered promising candidates for the development of new-generation antibiotics. Therefore, new antibiotic discoveries are needed. AMPs are suitable molecules for new-generation antibiotics that are both fast and have different killing mechanisms. One of the biggest problems in the clinical applications of AMPs is their poor stability. AMPs generally have limited tropical applications because they are sensitive to protease degradation. Coating these peptides with nanomaterials to make them more stable can solve this problem.

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.

Methods: 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.

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

Introduction: Pleckstrin homology and RhoGEF domain-containing G7 (PLEKHG7) is a largely uncharacterized gene whose role in diffuse large B-cell lymphoma (DLBCL) remains unexplored. Thus, we aimed to profile PLEKHG7 expression, assess its prognostic value, and explore therapeutic implications.

Methods: RNA-seq data from TCGA-DLBCL (n=48) and GTEx normal tissues were analyzed via UCSC XENA. Differential expression was tested using the Wilcoxon rank-sum test and FDR correction. Prognostic significance was evaluated by Kaplan-Meier and multivariate Cox regression (nomogram). Gene set enrichment analysis (GSEA) mapped PLEKHG7-associated pathways. Drug sensitivity correlations were extracted from RNAactDrug. qRT-PCR validated expression in DLBCL cell lines (OCI-Ly3, SU-DHL-4) versus normal B lymphocytes (GM12878).

Results: PLEKHG7 was markedly up-regulated in DLBCL tissues (P < 0.001) and cell lines versus normal controls (AUC = 0.739). High PLEKHG7 expression predicted inferior overall survival (HR = 8.88; 95% CI: 1.09-72.27; P = 0.041) and remained an independent prognostic factor (HR = 10.109; P = 0.033). GSEA linked PLEKHG7 to ribosome, oxidative phosphorylation, proteasome, cytokine-cytokine receptor interaction, spliceosome, and ECM-receptor pathways. Elevated PLEKHG7 negatively correlated with sensitivity to idelalisib, omipalisib, belinostat, methotrexate, and dacinostat.

Discussion: The study's limitations include reliance on bioinformatics data and the lack of functional validation. Further research is needed to elucidate the molecular mechanisms underlying PLEKHG7's role in DLBCL and validate its clinical utility.

Conclusion: PLEKHG7 is significantly overexpressed in DLBCL and independently predicts poor prognosis. Its association with key oncogenic pathways and drug resistance underscores its potential as both a prognostic biomarker and a therapeutic target, warranting further functional validation.

Introduction: Liver cancer is the third leading cause of cancer-related death. Plantderived therapeutics have played a significant role in preventing and treating many diseases, including cancers. The present study investigated the anticancer properties of protein fractions from the green leaf extract of Adenium obesum (A. obesum) in the laboratory.

Methods: Protein fractions of leaf extract were separated using reversed-phase high-performance liquid chromatography (RP-HPLC). The cytotoxicity of protein fractions was studied by MTT and sulforhodamine B assays. The apoptotic cell death was examined using the alkaline comet assay, and redox-related indicators were assessed using the catalase enzyme activity assay, glutathione content, and nitric oxide release. The RBC hemagglutination test investigated the possible presence of ribosome-inactivating proteins (RIPs) in the most toxic protein fraction, and the LD50 of the protein fraction with the highest anticancer effects was determined. The amino acid sequence of fraction proteins was determined by the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) method.

Results: The results showed that protein fraction 8 had the highest toxicity in the HepG2 cell line, with an IC₅₀ of 0.16 μg/mL. This fraction induced hemagglutination in red blood cells at concentrations higher than 65 μg/mL. The apoptosis was induced in the HepG2 cells following treatment with the concentrations of 0.08, 0.16, 0.32, and 0.64 μg/mL. Moreover, the redox potential of the treated cells was changed after treatment. The in vivo cytotoxicity investigation of this fraction in mice showed that it is not toxic for animals in concentrations up to 800 μg/kg, indicating its safety potential for pharmaceutical applications. The protein extract in the aforementioned fraction contained two proteins (22 and 53 kD) as determined by electrophoresis and sequencing methods.

Conclusion: The findings of this investigation demonstrated that the protein content of fraction 8 derived from A. obesum leaf extract possesses anticancer activity in the HepG2 cell line. The two isolated proteins from this fraction are novel and have been reported for the first time. Further investigations should be performed to evaluate the treatment potential in in vitro/vivo conditions.

The natural horizon of the genetic code has expanded to incorporate amino acids, such as selenocysteine and pyrrolysine. Researchers have incorporated unnatural amino acids (UAAs) into target proteins, demonstrating increased protein functionality depending on their choice and target. The primary challenge in protein engineering is identifying novel antimicrobial short peptides effective against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.), which are categorized as multidrug-resistant (MDR). UAAs can be preferentially incorporated into short peptides to display therapeutic activity, potentially leading to next-generation targeted therapeutics. In purview of this, we have curated and summarized the applicability of genetic incorporations of UAAs in antimicrobial short peptides with a special emphasis on the importance of green synthesis. The approach affirmed a reduction in the toxicity of peptide drugs, making it biocompatible. This is an efficient protocol to develop novel antimicrobial short peptides catering to precision medications, particularly against MDR pathogens, as a sustainable pharmaceutical approach.

Objective: This study aimed to identify novel proteins involved in retinoic acid (RA)-induced embryonic cleft palate development.

Methods: The palate tissues of the control and RA-treated E14.5 were dissected and subjected to iTRAQ-based proteomic analysis.

Results: Differential expression analysis identified 196 significantly upregulated and 149 downregulated considerably proteins in RA-induced palate tissues. Comprehensive Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed the significant involvement of cytoplasmic translation, ribosome biogenesis, glycolysis/gluconeogenesis, and glutathione metabolism pathways in cleft palate pathogenesis triggered by RA. In particular, ribosome-related pathways were highly enriched, while glycolysis was disrupted. Protein-protein interaction analysis, facilitated by the STRING database, revealed a tightly interconnected network of differentially expressed proteins. Further analysis using the cytoHubba plugin in Cytoscape identified ten hub proteins, including Eif4a1, Gapdh, Eno1, Imp3, Rps20, Rps27a, Eef2, Hsp90ab1, Rpl19, and Rps16, indicating their potential roles in RA-induced cleft palate development, and thus positioning them as potential biomarkers for cleft palate.

Conclusion: These findings provide valuable insights into the proteomic changes associated with RA-induced cleft palate and shed light on key pathways and proteins that can contribute significantly to the pathogenesis of this congenital condition.

Alzheimer's disease (AD) treatments currently available have ineffective results. Previously employed Acetylcholine esterase inhibitors and memantine, an NMDA receptor antagonist, target a single target structure that plays a complex role in the multifactorial progression of disease. Memantine moderates the toxic effects of excessive glutamate activity by blocking NMDA receptors, which decreases neurotoxicity in AD, while acetylcholine esterase inhibitors function by blocking cholinergic receptors (muscarinic and nicotinic), preventing the breakdown of acetylcholine, thereby enhancing cholinergic transmission, thus improving cognitive functions in mild to moderate stages of AD. Every drug class targets a distinct facet of the intricate pathophysiology of AD, indicating the diverse strategy required to counteract the advancement of this neurodegenerative disorder. Thus, patients are currently not getting much benefit from current drugs. A closer look at the course of AD revealed several potential target structures for future drug discovery. AD drug development strategies focus on developing new target structures in addition to well-established ones for combination treatment regimens, ideally with a single drug that can target two different target structures. Because of their roles in AD progression pathways like pathologic tau protein phosphorylations as well as amyloid β toxicity, protein kinases have been identified as potential targets. This review will give a quick rundown of the first inhibitors of single protein kinases, such as glycogen synthase kinase (gsk3) β, along with cyclin-dependent kinase 5. We will also look into novel inhibitors that target recently identified protein kinases in Alzheimer's disease, such as dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A). Additionally, multitargeting inhibitors, which target multiple protein kinases as well as those thought to be involved in other processes related to AD will be discussed. This kind of multitargeting offers prospective hope for improved patient outcomes down the road since it is the most effective way to impede multifactorial disease development.

Background: The role of Zona pellucida glycoprotein 3 (ZP3) is unclear in pancreatic adenocarcinoma (PAAD).

Objective: This study aimed to explore the role of ZP3 in PAAD.

Methods: A comparative analysis of ZP3 gene expression was performed to discern differences between various types of cancer and PAAD, leveraging data sourced from The Cancer Genome Atlas (TCGA). This study aimed to assess the role of ZP3 as a potential diagnostic marker for PAAD. The relationship between ZP3 levels and clinical characteristics, as well as patient outcomes, was scrutinized. Additionally, genomic enrichment analysis was carried out to uncover the underlying regulatory mechanisms associated with ZP3. The study further delved into the association of ZP3 with immune system interactions, checkpoint gene expression, Tumor Mutational Burden (TMB), microsatellite instability (MSI), and tumor stemness index (mRNAsi). The aberrant expression patterns of ZP3 in PAAD cell cultures were confirmed through the application of quantitative reverse transcription PCR (qRT-PCR) techniques.

Results: ZP3 exhibited aberrant expression in both pan-cancer and PAAD. A significant correlation was observed between increased levels of ZP3 expression in PAAD patients and histologic grade (p = 0.026). Elevated ZP3 expression in PAAD was found to be significantly associated with poorer overall survival (p = 0.003), progression-free survival (p = 0.012), and disease-specific survival (p = 0.002). In PAAD, the level of ZP3 gene expression was statistically significant (p < 0.001) and recognized as a key determinant of patient prognosis. ZP3 exhibited associations with various biological pathways, including primary immunodeficiency, oxidative phosphorylation, and other pathways. ZP3 expression demonstrated correlations with immune infiltration, immune checkpoint genes, TMB, MSI, and mRNAsi in PAAD. Moreover, a pronounced negative correlation was detected between ZP3 expression levels and the therapeutic effectiveness of various medications, including selumetinib, bleomycin, FH535, docetaxel, and tanespimycin, within the context of PAAD. Elevated levels of ZP3 were consistently observed in cell line models of PAAD.

Conclusion: ZP3 has the potential to serve as a prognostic biomarker and therapeutic target for patients with PAAD.

Autophagy is a self-eating cellular process in which the cell breaks down worn-out organelles, damaged/defective proteins, and toxins. Impaired autophagy is a significant factor in the development of various metabolic disorders, along with oxidative stress, inflammation, mitochondrial and endoplasmic reticulum dysfunction. These disorders pose a significant health and economic burden on the global human population, owing to their steadily rising prevalence. Therefore, modulating the expression of proteins involved in the autophagy-related pathways can be a promising avenue for curbing the development and progression of these disorders. Humanin (HN) is a 24-amino acid mitochondrial-derived peptide. It possesses anti-oxidant, anti-inflammatory, and pro-apoptotic properties. The analogs of HN can be generated by replacing specific amino acids in the polypeptide chain, thereby functionally modifying the peptide. Among these, humanin- glycine (HNG) is the most widely studied analog in both in vivo and in vitro disease models. It is far more potent than HN, with a potency that is 1000 times greater. To the best of our knowledge, this review is the first to discuss and examine the available evidence regarding the potential involvement of HN or its analogs in regulating autophagy pathways. The review primarily highlights that HN is an autophagy inducer, which can promote cell survival in the presence of metabolic and oxidative stress, particularly the HNG analog. Future research is imperative to comprehensively evaluate the effects of HN and its analogs on autophagy. Further investigations are needed to correlate its levels with various autophagic markers in different metabolic diseases, offering the potential for groundbreaking discoveries in understanding disease mechanisms and developing novel therapeutic strategies.

Introduction: The present study aims to compare the monotherapy of diosmetin and 5- hydroxydecanoate (5-HD) against the therapeutic effect of their combination therapy in the unilaterally injected rotenone-induced neurotoxicity in the male rats. Motor deficits accompany Parkinson's Disease (PD), while Bioflavonoids like diosmetin, which are antioxidants and anti-inflammatories, protect against neurotoxins. Moreover, mitochondrial dysfunction contributes to PD. The mitochondrial ATP-sensitive potassium channel [mito(KATP)] regulates reactive species and 5-HD, meaning decreasing it may lessen mitochondrial injury. To evaluate the effect of diosmetin, alone and in combination with 5-HD, on Oxidative Stress (OS) markers, mitochondrial function, and dopaminergic preservation in the SNpc.

Methods: Male Wistar rats were divided into seven groups, including normal control, sham, rotenone-treated, and treatment groups receiving diosmetin, 5-HD, their combination, or selegiline as a standard drug. Biochemical assays were conducted to assess OS markers, mitochondrial complex- I activity, and dopaminergic neuroprotection. Behavioral tests were performed to evaluate motor deficits.

Results: Rotenone administration significantly increased OS, impaired mitochondrial complex-I activity, and reduced motor coordination. Diosmetin treatment significantly reverses the effects of rotenone. Combined treatment with diosmetin and 5-HD showed enhanced neuroprotective effects compared to individual treatments.

Discussion: This study demonstrates that both diosmetin and 5-HD monotherapies alleviate rotenone-induced behavioral impairments in the experimental rats. Additionally, the individual treatment of diosmetin and 5-HD reduces dopaminergic toxicity induced by rotenone. At the sub-- cellular level, diosmetin and 5-HD monotherapies counteract rotenone's impact on antioxidant markers, DA metabolites, and mitochondrial function in the SNpc region of the brain. Notably, combining diosmetin and 5-HD yielded superior therapeutic effects on rotenone-induced behavioral and molecular changes compared to either monotherapy alone. These findings suggest that diosmetin and 5-HD may offer a promising alternative for PD management.

Conclusion: Diosmetin exhibits potent antioxidant and neuroprotective properties against rotenone-induced PD-like pathology. The combination of diosmetin and 5-HD offers a synergistic therapeutic potential, suggesting a promising approach for managing oxidative stress and mitochondrial dysfunction in PD.