Protein and Peptide Letters最新文献

{"title":"Role of 5-Hydroxydecanoate in the Neuroprotective Activity of Diosmetin Against Rotenone-Induced Dopaminergic Toxicity in Rats.","authors":"Krishna Kumar Varshney, Jeetendra Kumar Gupta, Rajnish Srivastava","doi":"10.2174/0109298665398088250904074136","DOIUrl":"10.2174/0109298665398088250904074136","url":null,"abstract":"<p><strong>Introduction: </strong>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.</p><p><strong>Methods: </strong>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.</p><p><strong>Results: </strong>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.</p><p><strong>Discussion: </strong>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.</p><p><strong>Conclusion: </strong>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.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":" ","pages":"637-649"},"PeriodicalIF":1.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145346696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cloning, Expression, Purification, and Characterization of Superoxide Dismutase from the Soil Metagenome.","authors":"Nancy, Sudarshan Singh Lakhawat, Rajender Kumar, Pushpender Kumar Sharma","doi":"10.2174/0109298665415743250926072254","DOIUrl":"10.2174/0109298665415743250926072254","url":null,"abstract":"<p><strong>Introduction: </strong>Superoxide Dismutases (SODs) are enzymes that catalyzes the conversion of toxic free radicals generated during stress conditions into nontoxic forms. Thus, the enzyme superoxide dismutase contributes to the adaptation and survival of microorganisms across a variety of environmental conditions, making it an indispensable enzyme during the response to stress. In this study, we embarked upon investigating and characterizing a Superoxide Dismutase (SOD) from DNA extracted directly from garden soil, where the average temperature ranges from 4°C- 45°C.</p><p><strong>Materials and methods: </strong>Metagenomic DNA was extracted by employing a kit. The gene was amplified using PCR. The amplified PCR product was gel eluted and ligated into the pGEMT-easy vector, followed by its subcloning in an expression vector. The protein was purified using Ni-NTA chromatography and characterized using biophysical, biochemical, and computational approaches.</p><p><strong>Results: </strong>The recombinant SOD was expressed and purified; the purified protein exhibited activity and stability over a broad pH and temperature range, with optimal activity observed at 40°C and pH 8, respectively. The enzyme remains completely stable at 40°C for 3 h. However, in contrast, it loses 50% of its activity when incubated at 50°C and 60°C for 3 h. The biophysical investigation revealed stable conformation of the secondary structure of the protein, as evident from circular dichroism and intrinsic Tryptophan (Trp) fluorescence studies. <i>In silico</i> sequence and structural analysis revealed a close similarity of the SOD reported in this study to the Mn SOD of multi- Bacillus species. Molecular simulation dynamics experiments revealed the all-over conformational stability of protein structures at varying pH, indicating broad pH functioning of the enzyme.</p><p><strong>Discussion: </strong>The study provides a comprehensive analysis of the structure and function of a superoxide dismutase enzyme derived from a soil metagenome. A Mn²⁺ binding site identified in the study offers an opportunity to further facilitate engineering and design of mutant SOD.</p><p><strong>Conclusion: </strong>The enzyme exhibits distinct attributes that hold significant industrial relevance. Owing to the wide functionality of SOD at different pH and temperature, it can be tailored for its potential industrial applications, including therapeutic potential, thus opening new avenues for enhanced antioxidant therapies and novel biocatalyst designing.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":" ","pages":"667-678"},"PeriodicalIF":1.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145233255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Regulatory Interaction of Differentially Expressed Proteins in Cleft Palate Induced by Retinoic Acid.","authors":"Liyun Chen, Aiwei Ma, Lewen Jiang, Jufeng Fan, Wenshi Jiang, Mengjing Xu, Xujue Bai, Jianda Zhou, Wancong Zhang, Shijie Tang","doi":"10.2174/0109298665308502240820115618","DOIUrl":"10.2174/0109298665308502240820115618","url":null,"abstract":"<p><strong>Objective: </strong>This study aimed to identify novel proteins involved in retinoic acid (RA)-induced embryonic cleft palate development.</p><p><strong>Methods: </strong>The palate tissues of the control and RA-treated E14.5 were dissected and subjected to iTRAQ-based proteomic analysis.</p><p><strong>Results: </strong>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.</p><p><strong>Conclusion: </strong>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.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":" ","pages":"54-61"},"PeriodicalIF":1.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142547006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring New Structures of Kinase Inhibitors and Multitarget Strategies in Alzheimer's Disease Treatment.","authors":"Siddhant Tripathi, Yashika Sharma, Dileep Kumar","doi":"10.2174/0109298665348075241121071614","DOIUrl":"10.2174/0109298665348075241121071614","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":" ","pages":"2-17"},"PeriodicalIF":1.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142882794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ZP3 Expression in Pancreatic Adenocarcinoma: Its Implications for the Prognosis and Therapy.","authors":"Guizhen Lyu, Dongbing Li","doi":"10.2174/0109298665350171241204153202","DOIUrl":"10.2174/0109298665350171241204153202","url":null,"abstract":"<p><strong>Background: </strong>The role of Zona pellucida glycoprotein 3 (ZP3) is unclear in pancreatic adenocarcinoma (PAAD).</p><p><strong>Objective: </strong>This study aimed to explore the role of ZP3 in PAAD.</p><p><strong>Methods: </strong>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.</p><p><strong>Results: </strong>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.</p><p><strong>Conclusion: </strong>ZP3 has the potential to serve as a prognostic biomarker and therapeutic target for patients with PAAD.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":" ","pages":"124-138"},"PeriodicalIF":1.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142953980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Review on the Potential Role of Humanin Peptide and its Analogs in the Regulation of Autophagy Pathways for Therapeutic Application in Metabolic Disorders.","authors":"Hira Moin, Rizwan Ashraf, Batool Butt, Imtiaz Mustafa, Mamoona Shafiq, Syed Ali Raza Shah","doi":"10.2174/0109298665363711250112050930","DOIUrl":"10.2174/0109298665363711250112050930","url":null,"abstract":"<p><p>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 <i>in vivo</i> and <i>in vitro</i> 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.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":" ","pages":"161-170"},"PeriodicalIF":1.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143415052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prolyl 4-Hydroxylase Beta Peptide Promotes Invasion, Migration, and Epithelial-Mesenchymal Transition through Activation of the Claudin-1/ AMPK/TGF-β1 Pathway in Bladder Cancer Cells.","authors":"Mingning Qiu, Shuai Zhang, Jinglan Liang, Genyin Chen, Jie Liu","doi":"10.2174/0109298665418763251124051527","DOIUrl":"10.2174/0109298665418763251124051527","url":null,"abstract":"<p><strong>Introduction: </strong>Prolyl 4-hydroxylase beta peptide (P4HB) is a novel diagnostic and prognostic marker associated with cancer progression and clinical outcomes, and it is upregulated in multiple types of cancer cells. However, the influence and potential mechanisms of P4HB on the migration, invasion, and epithelial-mesenchymal transition (EMT) of bladder cancer cells remain unclear. This study aims to clarify the role of P4HB in the migration, invasion, and EMT of bladder cancer cells and to explore its potential mechanism related to the Claudin-1/AMPK/TGF-β1 pathway.</p><p><strong>Methods: </strong>The mRNA and protein expression levels of P4HB were examined in human ureteral epithelial cells (SV-HUC-1) and five bladder cancer cell lines (J82, T24, 5637, UM-UC-3, and RT4). Stable cell lines with P4HB overexpression and knockdown were constructed, and the effects of P4HB on migration, invasion, EMT, and the expression of EMT-related genes in bladder cancer cells were analyzed using wound healing assays, Transwell invasion assays, cellular morphology observations, real-time quantitative PCR, in-cell western blotting, western blotting, and enzymelinked immunosorbent assays. Furthermore, Claudin-1 siRNA was transfected into P4HBoverexpressing cells to investigate its potential role in P4HB-induced invasion and EMT in bladder cancer cells.</p><p><strong>Results: </strong>P4HB mRNA and protein expressions were significantly upregulated in human bladder cancer cell lines compared to those in ureteral epithelial cells. Cell migration, invasion, and EMT were significantly promoted in P4HB-overexpressing stable bladder cancer cells and suppressed in P4HB-knockdown cells. Furthermore, interference with P4HB downregulated EMT-related Claudin-1 mRNA and protein expressions and regulated the expression of downstream genes and proteins of Claudin-1. Moreover, interference of Claudin-1 with its siRNA significantly reversed the invasion and EMT induced by P4HB-overexpression, however, the effect of Claudin-1 siRNA was revised by TGF-β1 agonist and AMPK inhibitor.</p><p><strong>Conclusion: </strong>P4HB promoted migration, invasion, and EMT of bladder cancer cells by activating the Claudin-1/AMPK/TGF-β1-related pathway.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":" ","pages":"822-835"},"PeriodicalIF":2.5,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146053364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clay-Polymer Nanocomposites Mediated Inhibition of Protein Aggregation: Possible Role in the Prevention of Proteinopathies.","authors":"Romana Parveen, Sher Ali, Sadaf Fatima","doi":"10.2174/0109298665274059231002071951","DOIUrl":"10.2174/0109298665274059231002071951","url":null,"abstract":"<p><strong>Background: </strong>The transformation of proteins from their native conformation into highly ordered fibrillar structures due to their misfolding and aggregation under particular conditions are described as beta-sheet enriched amyloid fibrils. The accumulation of these fibrils in different body parts is the major cause of several neurological and non-neurological conditions (proteinopathies).</p><p><strong>Objectives: </strong>To prevent these proteinopathies, inhibition of protein aggregation is considered a promising strategy. Therefore, in this study, we synthesized montmorillonite (MMT) based poly- orthophenylenediamine (PoPD) nanocomposites (NCs) and characterized their size and morphology due to their remarkable biological properties. Further, the effect of these nanocomposites on inhibition of fibril formation was assessed.</p><p><strong>Methods: </strong>These nanocomposites were evaluated for their anti-amyloidogenic potential on two model proteins of amyloidopathies, i.e., human lysozyme and human serum albumin (HL & HSA), by using several biophysical methods, such as Thioflavin T (ThT) and 1-anilino-8-naphthalene sulfonate (ANS) fluorescence, congo red dye binding assay (CR). Secondary structural content was evaluated by Circular dichroism (CD) spectroscopy.</p><p><strong>Results: </strong>Results demonstrated that synthesized nanocomposites significantly inhibited fibril formation in dose-dependent manner that corresponds to their ability to arrest fibrillation. It is suggested that they may adsorb proteins to protect them against aggregation when they are subjected to aggregating conditions.</p><p><strong>Conclusion: </strong>This study offers an opportunity to understand the mechanism of inhibition of fibril formation by nanocomposites, showing that they inhibit amyloid formation and amyloid diseases. Thus, the study concludes that these nanocomposites are promising candidates as therapeutic molecules for proteinopathies and are envisaged to enrich the area of personalized medicine, augmenting the human healthcare system.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":" ","pages":"139-151"},"PeriodicalIF":1.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49681633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expression, Purification, and Preliminary Characterization of Putative Protein Tyrosine Phosphatase Oca1.","authors":"Madhu Patel, Ashutosh Kumar, Kam Y J Zhang, Md Sohail Akhtar","doi":"10.2174/0109298665388367250404095840","DOIUrl":"10.2174/0109298665388367250404095840","url":null,"abstract":"<p><strong>Introduction/objective: </strong>Protein phosphatases act as counterparts to protein kinases and are considered crucial for the homeostatic balance of cell signalling. In contrast to kinases, which can be categorized according to their substrate specificity, phosphatases are versatile and can detect substrates with much less distinction; hence, it is challenging to identify the physiological phosphatase-substrate pair. The Oca1 of Saccharomyces cerevisiae is a putative protein tyrosine phosphatase (PTP) and is required for cell cycle arrest in response to oxidative stress. The Oca1 mutants are sensitive to mTOR inhibitors, such as caffeine and rapamycin, and are involved in the regulation of TOR function. In an earlier research work, the enzyme exhibited no in vitro phosphatase activity and it was suggested that post-translational modifications or additional factors are necessary for it to be functional.</p><p><strong>Methods: </strong>The modeling of Oca1 was performed to gain insight into the structural aspects. The full- length enzyme, as well as the enzyme without the N-terminal extension, was cloned, expressed, and purified to homogeneity. The structure, function, and stability of the purified enzyme were assessed using circular dichroism, fluorescence, and visible spectroscopy studies.</p><p><strong>Results: </strong>The Oca1 was expressed and purified from Escherichia coli. The enzyme has been found to be functional, stable, and exist in an extended monomeric form, with a molecular mass of about 27 kDa. The enzyme without the extended N-terminal random coil has also been functional and slightly more stable than the full-length Oca1.</p><p><strong>Conclusion: </strong>The purified functional enzyme may be used to gain insights into the biochemical aspects and its role in bioengineering.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":" ","pages":"235-242"},"PeriodicalIF":1.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144029012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inconsistent Protein Stability Despite Pre-HECT Domain Helix: Unveiling Variability in HECT Ligases.","authors":"Cagdas Dag, Cansu Deniz Tozkoparan Ceylan, Cemre Sare Cansız","doi":"10.2174/0109298665362863250114075840","DOIUrl":"10.2174/0109298665362863250114075840","url":null,"abstract":"<p><strong>Introduction: </strong>Ubiquitin and ubiquitin-like systems play crucial roles across a wide range of organisms, from simple to complex. Among the three enzyme-mediated post-translational modification (PTM) steps, the ligation step is the most critical. HERC5, a member of the HECT ligase family, is one of the three enzymes involved in the ISGylation system. However, the precise start points and lengths of the HECT domains in HECT ligases are still under debate.</p><p><strong>Methods: </strong>Some studies suggest the inclusion of an additional N-terminal alpha helix region within the HECT domain. To investigate the structural biology of the HECT domain of HERC5, we produced and purified various lengths of the HERC5 HECT domain using different fusion proteins. This approach allowed us to explore the role of the N-terminal alpha helix in the stability of the HECT domain. Our experiments successfully produced and purified HERC5 HECT domains of different lengths with various fusion proteins.</p><p><strong>Results: </strong>The findings demonstrated that the N-terminal alpha-helix does not enhance the stability of the HECT domain. These results challenge the notion that the N-terminal alpha-helix should be generally included in the HECT domain across all HECT ligases.</p><p><strong>Conclusion: </strong>The inclusion of this region within the HECT domain may not be appropriate for generalization, as it does not contribute to stability, contrary to some previous suggestions.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":" ","pages":"269-279"},"PeriodicalIF":1.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143415056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}