The Protein Journal最新文献_第7页

Exploring Wheat Leaf Urease for a Sustainable Approach: Purification, Kinetics, and Thermal Stability Characterization 探索小麦叶片脲酶的可持续途径：纯化、动力学和热稳定性表征。

IF 1.4 4区生物学

The Protein Journal Pub Date : 2025-09-15 DOI: 10.1007/s10930-025-10291-8

Surbhi Sahewalla, Sonam Sihag, Anil Duhan, Vinod Saharan, Ajay Pal

{"title":"Exploring Wheat Leaf Urease for a Sustainable Approach: Purification, Kinetics, and Thermal Stability Characterization","authors":"Surbhi Sahewalla, Sonam Sihag, Anil Duhan, Vinod Saharan, Ajay Pal","doi":"10.1007/s10930-025-10291-8","DOIUrl":"10.1007/s10930-025-10291-8","url":null,"abstract":"<div><p>The urease enzyme has an inevitable application in cereal crops, particularly in response to foliar urea application. A holistic and novel approach was employed in the present work with the aim to purify and characterize the wheat leaf urease. This will help in exploring and enhancing its activity in assimilation of foliar urea application and a move towards sustainability. Wheat urease was purified to electrophoretic homogeneity with a 41.98 fold purification and 36.3% recovery. The molecular weight of the native enzyme was found to be ~ 290 kDa by Gel Filtration Chromatography (GFC), and a single band in Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) of ~ 103 kDa deduced its homotrimeric nature. The enzyme had a K<sub>m</sub> of 1.0 mM, V<sub>max</sub> of 63.25 units mL<sup>−1</sup>, turnover number of 30.26 min<sup>−1</sup>, and a specificity constant of 504.33 M<sup>−1</sup> sec<sup>−1</sup>. Further, the optimum pH was 7.5 with 40 °C optimum temperature. The E<sub>a</sub> of the purified urease was 61.36 kJ mol<sup>−1</sup>, with the E<sub>d</sub> as 104.3 kJ mol<sup>−1</sup>. The half-life and D-value decreased with an increase in temperature owing to the rapid loss of its catalytic activity. The z-value was calculated as 44.6 °C. The thermodynamic study revealed the interplay between ΔH, ΔG and ΔS during enzyme deactivation. Histidine was found to be present at the active site and Nickel enhanced the urease activity, whereas copper displayed an inhibitory effect. Hence, this study of wheat urease offers novel insights into an enzyme that has remained largely unexplored despite its inevitable importance in cereal crops. The measures for enhancing its activity in vivo can also be abstracted from this study.</p></div>","PeriodicalId":793,"journal":{"name":"The Protein Journal","volume":"44 6","pages":"729 - 741"},"PeriodicalIF":1.4,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145067149","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}

引用次数: 0

Design and Verification Process of a Structure-Altering Peptide as a Microtubule Allosteric Polypeptide Against Cancer 抗癌微管变构肽结构改变肽的设计与验证过程。

IF 1.4 4区生物学

The Protein Journal Pub Date : 2025-09-12 DOI: 10.1007/s10930-025-10290-9

Zhan Shi

{"title":"Design and Verification Process of a Structure-Altering Peptide as a Microtubule Allosteric Polypeptide Against Cancer","authors":"Zhan Shi","doi":"10.1007/s10930-025-10290-9","DOIUrl":"10.1007/s10930-025-10290-9","url":null,"abstract":"<div><p>The aim of this study was to design a novel structure-altering polypeptide (SAP) as an anti-microtubule against tumor cells. This series of SAP XA1–XA17 was synthesized by manual solid-phase synthesis and verified by high-performance liquid chromatography (HPLC) and mass spectrometry. Polypeptides were used in three normal cell lines and four tumor cell lines. The optimal polypeptide was selected. Molecular docking of the above optimal polypeptide with tubulin was performed. Tubulin polymerization experiment was performed to investigate effect of optimized peptide to tubulin polymerization. The effect of optimized peptide to cancer in vivo was tested in A549 xenograft tumor mice model. The results of mass spectrometry revealed that the molecular weights of the SAP XA1–XA17 samples were relatively consistent with the theoretical values, whereas the purities of the SAP XA1–XA17 series polypeptide samples were greater than 92.00%. Among the SAP XA1–17 polypeptides, the cell viability kit-8 (CCK-8) assay demonstrated that the XA5 polypeptide was nearly nontoxic to three normal cell lines and had excellent antitumor effects on four cancer cell lines. Molecular docking demonstrated that the polypeptide XA5 preferred tubulin. The docking energies are less than − 5 kcal/mol, verifying the excellent performance of the selected XA5 polypeptide. Tubulin polymerization experiment showed XA5 inhibited tubulin polymerization. In animal study, XA5 administration decreased A549 xenograft tumor weight. The XA5 polypeptide is an effective anti-microtubule drug.</p></div>","PeriodicalId":793,"journal":{"name":"The Protein Journal","volume":"44 6","pages":"824 - 838"},"PeriodicalIF":1.4,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145042651","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}

引用次数: 0

Decoding ATXN2 Phosphocode: Structural Insights and Therapeutic Opportunities in Disease 解码ATXN2磷码：结构洞察和疾病治疗机会。

IF 1.4 4区生物学

The Protein Journal Pub Date : 2025-08-30 DOI: 10.1007/s10930-025-10287-4

Apoorva Pai Kalasa Anil Kumar, Suhail Subair, Prathik Basthikoppa Shivamurthy, Samseera Ummar, Athira C. Rajeev, Rajesh Raju

{"title":"Decoding ATXN2 Phosphocode: Structural Insights and Therapeutic Opportunities in Disease","authors":"Apoorva Pai Kalasa Anil Kumar, Suhail Subair, Prathik Basthikoppa Shivamurthy, Samseera Ummar, Athira C. Rajeev, Rajesh Raju","doi":"10.1007/s10930-025-10287-4","DOIUrl":"10.1007/s10930-025-10287-4","url":null,"abstract":"<div><p>Ataxin-2 (ATXN2), a key RNA-binding protein, regulates RNA metabolism, stress granule formation, and neuronal homeostasis, with dysregulated phosphorylation contributing to Spinocerebellar Ataxia type 2 (SCA2), amyotrophic lateral sclerosis (ALS), and cancer. This review integrates structural biology, phosphoproteomics, and interactome analyses to map six critical phosphosites (S772, T741, S624, S684, S784, S889) within ATXN2’s intrinsically disordered regions. Modulated by kinases GSK3β and CDK13 and phosphatases like INPP5F, these sites orchestrate interactions with RNA-binding partners (e.g., ATXN2L, FXR2, STAU2) and co-regulated proteins (e.g., TP53BP1, NUP153), driving pathogenesis through disrupted autophagy, nucleocytoplasmic transport, and stress granule dynamics. We propose targeted therapies, including GSK3β inhibitors for ALS, antisense oligonucleotides for SCA2, and MTOR modulators for cancer, to restore ATXN2 function. By elucidating phosphocode of ATXN2, this work highlights novel avenues for precision medicine in neurodegenerative and oncogenic diseases.</p></div>","PeriodicalId":793,"journal":{"name":"The Protein Journal","volume":"44 5","pages":"483 - 500"},"PeriodicalIF":1.4,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144984702","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}

引用次数: 0

Structural Changes of Apolipoprotein A-I Caused by Hydroxyethyl Starch 130/0.4 Reveals Potential Toxic Mechanisms 羟乙基淀粉130/0.4引起的载脂蛋白A-I结构变化揭示潜在的毒性机制

IF 1.4 4区生物学

The Protein Journal Pub Date : 2025-08-30 DOI: 10.1007/s10930-025-10283-8

Lingyan Qu, Liqun Jia, Jianzhong Zhang, Shuqin Ni

{"title":"Structural Changes of Apolipoprotein A-I Caused by Hydroxyethyl Starch 130/0.4 Reveals Potential Toxic Mechanisms","authors":"Lingyan Qu, Liqun Jia, Jianzhong Zhang, Shuqin Ni","doi":"10.1007/s10930-025-10283-8","DOIUrl":"10.1007/s10930-025-10283-8","url":null,"abstract":"<div><p>6% hydroxyethyl starch (HES 130/0.4) is frequently employed to address hypovolemia, ensuring sufficient organ perfusion and oxygen transport. The effects on Apolipoprotein A-I (ApoA-I) were examined at three temperatures—280, 295, and 310 K—through several spectroscopic techniques to explore its possible interaction with the predominant protein in veins. The experimental findings indicated that HES 130/0.4 efficiently extinguished the intrinsic fluorescence of APOA-I. We also assessed the binding sites, binding constant, and thermodynamic parameters, which indicated that HES 130/0.4 can spontaneously associate with APOA-I via hydrogen bonds and van der Waals interactions (Δ<i>G</i> = − 1.93 × 10<sup>4</sup> J·mol<sup>−1</sup>, Δ<i>H</i> = − 5.63 × 10<sup>4</sup> J mol⁻<sup>1</sup>, and Δ<i>S</i> = − 119 J mol⁻<sup>1</sup> K⁻<sup>1</sup>) with a single binding site and week binding forces (<i>n</i> = 1.03 and <i>K</i><sub><i>A</i></sub> = 1.78 × 10<sup>3</sup> M<sup>−1</sup>) at body temperature. Moreover, the structure of APOA-I was significantly altered in the presence of HES 130/0.4. Blood Ca<sup>2+</sup> and Fe<sup>3+</sup> will diminish the storage duration. The study provides accurate and thorough foundational data to clarify the binding mechanisms of HES 130/0.4 with APOA-I in vitro, which may help the comprehension of its impact on protein function and toxic mechanism during transit and distribution in the bloodstream.</p></div>","PeriodicalId":793,"journal":{"name":"The Protein Journal","volume":"44 5","pages":"667 - 674"},"PeriodicalIF":1.4,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144984625","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}

引用次数: 0

Characterization and Evolutionary Study of Fungal Nitrate Reductase Through Bioinformatics and Partial Gene Amplification from Aspergillus niger PKA16 employing Degenerate Primers 利用退化引物扩增黑曲霉PKA16部分基因及生物信息学鉴定真菌硝酸还原酶的进化研究

IF 1.4 4区生物学

The Protein Journal Pub Date : 2025-08-29 DOI: 10.1007/s10930-025-10288-3

Amrita Banerjee, Milan Kumar Samanta, Mehak Kanwar, Smarajit Maiti, Keshab Chandra Mondal, Hrudayanath Thatoi, Pradeep Kumar Das Mohapatra

{"title":"Characterization and Evolutionary Study of Fungal Nitrate Reductase Through Bioinformatics and Partial Gene Amplification from Aspergillus niger PKA16 employing Degenerate Primers","authors":"Amrita Banerjee, Milan Kumar Samanta, Mehak Kanwar, Smarajit Maiti, Keshab Chandra Mondal, Hrudayanath Thatoi, Pradeep Kumar Das Mohapatra","doi":"10.1007/s10930-025-10288-3","DOIUrl":"10.1007/s10930-025-10288-3","url":null,"abstract":"<div><p>Nitrate contamination in water sources creates major health risks that primarily affect infants by causing methemoglobinemia (“blue baby syndrome”) while also leading to congenital defects and cancer development. The human body absorbs nitrates mainly through drinking contaminated water. Enzyme nitrate reductase (NR) produced by microorganisms, functions as a key factor in nitrate detoxification. A partial NR gene (GenBank accession: MN833805) from <i>Aspergillus niger</i> PKA16 (KY907172.1) was amplified by employing degenerate primers in this research. The primer sequences were designed based on conserved protein motifs and orthologous diversity analysis of 399 NR protein sequences spanning 127 fungal genera. The NR proteins exhibited an extensive range which demonstrated extensive intra- and interspecies diversity. The multiple conserved domains included nine motifs which remained consistent despite the observed sequence variability. Two highly conserved sequences RLTGKHPFN and PDHGYPLRLV were validated through degenerate-PCR which demonstrated their effectiveness for partial NR gene detection and amplification. In the present study, the developed degenerate primers enable researchers to detect and amplify NR genes from majority of known and unknown fungal strains including those identified through metagenomic studies also. This research establishes fundamental principles for using biotechnology to amplify bioremediatory enzyme nitrate reductase from fungal origin to clean up water and food that contains nitrates, to reduce the risk of ‘blue baby’ disease and cancer.</p></div>","PeriodicalId":793,"journal":{"name":"The Protein Journal","volume":"44 5","pages":"654 - 666"},"PeriodicalIF":1.4,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144984655","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}

引用次数: 0

Effect of Mutations on the Evolution of Extended Spectrum β-lactamases (ESBL) 突变对扩展谱β-内酰胺酶（ESBL）进化的影响。

IF 1.4 4区生物学

The Protein Journal Pub Date : 2025-08-19 DOI: 10.1007/s10930-025-10284-7

Anirudha Dutta, Antarika Chowdhury, Parijat Roy, Priyanka Bhowmik

{"title":"Effect of Mutations on the Evolution of Extended Spectrum β-lactamases (ESBL)","authors":"Anirudha Dutta, Antarika Chowdhury, Parijat Roy, Priyanka Bhowmik","doi":"10.1007/s10930-025-10284-7","DOIUrl":"10.1007/s10930-025-10284-7","url":null,"abstract":"<div><p>Bacterial antimicrobial resistance is a great public health threat worldwide, a situation that is much escalated by the rapid propagation of Extended Spectrum β-lactamase (ESBL) enzymes. These can hydrolyze and inactivate a broad range of β-lactams, including third-generation cephalosporins, penicillin, and aztreonam and are known to be associated with various bacterial infections, ranging from uncomplicated urinary tract infections to life-threatening sepsis.Variation is the essential raw material of Darwinian evolution and the accumulation of mutations plays one of the most important roles in it. Sequential acquisition of spontaneous mutations followed by successive rounds of selection can be attributed as one of the major reasons for the rapid diversification of ESBL enzymes. The ESBLs are excellent examples of ‘microevolution’ that led to ‘gain-of-function’ with an extended substrate spectrum. However, acquiring newer phenotypes sometimes comes with fitness costs and different mutational pathways interact with each other, triggering both additive and non-additive fitness to generate a rugged fitness landscape, that influences the path a strain must follow to adapt and evolve under selection pressure. Therefore, it is important to understand the role of mutations in the emergence of these enzyme variants. This review focuses on the understanding of different facades of mutational pathways that lead to the adaptive evolution of ESBL phenotype. The structural and mechanistic basis of the extension of the substrate spectrum by mutations are also discussed.</p></div>","PeriodicalId":793,"journal":{"name":"The Protein Journal","volume":"44 5","pages":"501 - 525"},"PeriodicalIF":1.4,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144884649","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}

引用次数: 0

Revealing the Bacterial HslV Protease Activation Potential with Triazine Derivatives via Experimental and Computational Approaches 通过实验和计算方法揭示细菌HslV蛋白酶与三嗪衍生物的激活电位。

IF 1.4 4区生物学

The Protein Journal Pub Date : 2025-08-19 DOI: 10.1007/s10930-025-10286-5

Sana Aurangzeb, Muhammad Aurongzeb, Mehwish Hamid, Yasmeen Rashid, Shahbaz Shamim, Khalid Mohammed Khan, Tariq Aziz, Nawal Al-Hoshani, Maher S. Alwethaynani, Fakhria A. Al-Joufi

{"title":"Revealing the Bacterial HslV Protease Activation Potential with Triazine Derivatives via Experimental and Computational Approaches","authors":"Sana Aurangzeb, Muhammad Aurongzeb, Mehwish Hamid, Yasmeen Rashid, Shahbaz Shamim, Khalid Mohammed Khan, Tariq Aziz, Nawal Al-Hoshani, Maher S. Alwethaynani, Fakhria A. Al-Joufi","doi":"10.1007/s10930-025-10286-5","DOIUrl":"10.1007/s10930-025-10286-5","url":null,"abstract":"<div><p>The bacterial HslVU enzyme complex consists of two components: the HslV protease and the HslU ATPase. This complex share both structural and sequence similarities with the eukaryotic proteasome. HslV becomes functionally active upon engagement with HslU, which inserts its C-terminal helix into a conserved groove within the HslV dimer. This interaction triggers allosteric modulation, thereby initiating HslV’s proteolytic activity. Because the HslVU system is present in pathogenic bacteria but absent in humans, it represents a promising target for antibacterial drug development. This study focuses on the discovery of small molecules that hyperactivate HslV, leading to excessive protein degradation in harmful bacterial strains. By integrating computational modeling with laboratory assays, four triazine-based compounds were identified as potent activators of HslV. These molecules demonstrated high binding affinity in docking simulations, favorable interaction profiles, and significant activation in biochemical assays. Their ED₅₀ values ranged from 0.37 μM to 0.55 μM, indicating strong potency. Furthermore, ADMET evaluations revealed desirable pharmacokinetic and drug-likeness properties. Overall, this work presents effective, non-peptidic small-molecule activators of the HslV protease and provides new insights into chemical modulation of the HslVU system, offering a promising avenue for antibacterial drug discovery.</p></div>","PeriodicalId":793,"journal":{"name":"The Protein Journal","volume":"44 5","pages":"639 - 653"},"PeriodicalIF":1.4,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144884650","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}

引用次数: 0

Unveiling the Immunostimulatory Potential of the HSPA1A Mini-Chaperones Compared to the HSPA1A and HSP27 Chaperones: In Silico and In Vitro Insights for Vaccine Development 揭示HSPA1A迷你伴侣蛋白与HSPA1A和HSP27伴侣蛋白的免疫刺激潜力：在硅和体外对疫苗开发的见解

IF 1.4 4区生物学

The Protein Journal Pub Date : 2025-08-14 DOI: 10.1007/s10930-025-10285-6

Fatemeh Heidarnejad, Fateme Ekhlasi, Parisa Moradi Pordanjani, Fahime Nemati, Azam Bolhassani

{"title":"Unveiling the Immunostimulatory Potential of the HSPA1A Mini-Chaperones Compared to the HSPA1A and HSP27 Chaperones: In Silico and In Vitro Insights for Vaccine Development","authors":"Fatemeh Heidarnejad, Fateme Ekhlasi, Parisa Moradi Pordanjani, Fahime Nemati, Azam Bolhassani","doi":"10.1007/s10930-025-10285-6","DOIUrl":"10.1007/s10930-025-10285-6","url":null,"abstract":"<div><p>Molecular chaperones known as heat shock proteins (HSPs) are evolutionarily conserved and are critical in regulating immune system functions. To assess the immunostimulatory potential of HSPs, we employed advanced computational and experimental techniques. Bioinformatics tools were employed to analyze and confirm the physicochemical characteristics of the full-length HSPA1A, the fragments of HSPA1A known as minichaperones (C-terminal region of HSPA1A: CHSPA1A and N-terminal region of HSPA1A: NHSPA1A), and the full length HSP27, confirming their advantageous properties and structural integrity through 3D refinement and validation. Docking studies revealed significant interactions of HSPs with CD91 and TLR4 receptors respectively, notably a strong and stable binding of the full length HSPA1A and CHSPA1A with CD91. Molecular dynamics simulations were conducted to confirm the structural stability of the complexes formed between HSPs and CD91. Immunological simulations demonstrated robust and stable responses from both innate and adaptive immune cells against HSPs. All HSPs were produced in <i>E. coli</i>, isolated via Ni-NTA affinity chromatography, and subsequently utilized to stimulate immune cells from mice in vitro. The results showed significant secretion of TNF-α and IFN-γ in comparison to IL-10, indicating a directed T-helper 1 (cellular) immunity. The in silico and in vitro findings represented that HSPA1A and then CHSPA1A resulted in significantly greater TNF-α secretion in splenocytes co-cultured with the pulsed DCs compared to NHSPA1A and HSP27, suggesting their significant role in activating adaptive immunity. In contrast, macrophages exhibited an increased TNF-α secretion in response to HSP27, suggesting its involvement in modulating innate inflammatory processes. Understanding these differences can help in designing more effective immunotherapies.</p></div>","PeriodicalId":793,"journal":{"name":"The Protein Journal","volume":"44 5","pages":"611 - 638"},"PeriodicalIF":1.4,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144857316","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}

引用次数: 0

Characterization of S-homocysteinylation of Human Insulin and Its Implications in Diabetes 人胰岛素的s -同型半胱氨酸化特征及其在糖尿病中的意义。

IF 1.4 4区生物学

The Protein Journal Pub Date : 2025-07-23 DOI: 10.1007/s10930-025-10282-9

Amreen B. Sheikh, Swaraj M. Jathar, Vaishnavi Tammara, Atanu Das, Mahesh J. Kulkarni

{"title":"Characterization of S-homocysteinylation of Human Insulin and Its Implications in Diabetes","authors":"Amreen B. Sheikh, Swaraj M. Jathar, Vaishnavi Tammara, Atanu Das, Mahesh J. Kulkarni","doi":"10.1007/s10930-025-10282-9","DOIUrl":"10.1007/s10930-025-10282-9","url":null,"abstract":"<div><p>Homocysteine thiolactone is a reactive thiol known for its interaction with various proteins. Nevertheless, there exists a paucity of information concerning the interaction between homocysteine thiolactone and human insulin, particularly regarding the mechanism by which homocysteine facilitates the reduction of disulfide bonds within insulin. In the present study, we have elucidated the binding sites of homocysteine to the cysteine residues (A6-B7 and A20-B19) that are implicated in the formation of intermolecular disulfide bonds in insulin through an in vitro reaction analyzed via LC-ESI MS/MS. This results in a reduction of disulfide bonds linking the A and B chains, which was corroborated by MALDI-TOF-MS and ESI-MS analysis. The secondary structure of insulin is affected by this modification, as evidenced by circular dichroism spectroscopy. In-silico studies also show that homocysteine affects the insulin structure. A glucose uptake assay conducted in Chinese hamster ovary (CHO) cells that stably express the insulin receptor revealed that HC-modified insulin is less effective in inducing glucose uptake compared to native insulin, suggesting that HC-induced structural modifications in insulin influence functional activity. This study provides insight into the HC-induced structural and functional changes in insulin and discusses the consequent implications for diabetes.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":793,"journal":{"name":"The Protein Journal","volume":"44 5","pages":"598 - 610"},"PeriodicalIF":1.4,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144700805","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}

引用次数: 0

A Novel C-Terminal Small Tail Provides Thermostability of FeSOD Implying a New Mechanism of Protein Heat Resistance 新型的c端小尾提供了FeSOD的热稳定性，这意味着蛋白质耐热的新机制。

IF 1.4 4区生物学

The Protein Journal Pub Date : 2025-07-18 DOI: 10.1007/s10930-025-10280-x

Weina Lu, Zhuo Jiang, Qi Lin, Zhecheng Yang, Yanli Liu, Wenhui Bi, Zhengying You, Caiying Jiang, Qing Sheng, Zuoming Nie

{"title":"A Novel C-Terminal Small Tail Provides Thermostability of FeSOD Implying a New Mechanism of Protein Heat Resistance","authors":"Weina Lu, Zhuo Jiang, Qi Lin, Zhecheng Yang, Yanli Liu, Wenhui Bi, Zhengying You, Caiying Jiang, Qing Sheng, Zuoming Nie","doi":"10.1007/s10930-025-10280-x","DOIUrl":"10.1007/s10930-025-10280-x","url":null,"abstract":"<div><p>Superoxide dismutase (SOD) is found in a variety of organisms, including animals, plants, and microorganisms, and is widely used in medicine, food, and cosmetics. In this study, a novel heat-resistant SOD from <i>Rhodothermus</i> sp. XMH10 (RhSOD) has been found to have no loss of activity at 80 °C and exhibit high thermal stability across a temperature range from 20 °C to 80 °C. Unlike other reported SODs, RhSOD was found to have a unique small α-helix tail at the C-terminus, consisting of 11 amino acid residues. The absence of the C-terminal α-helix tail of RhSOD was shown to reduce its activity and thermal stability at 80 °C, suggesting that the C-terminal α-helix tail is crucial for the high thermal stability of RhSOD. Furthermore, the fusion of the C-terminal α-helix tail to the C-terminus of a thermophilic SOD from <i>Anoxybacillus caldiproteolyticus</i> (AcSOD) enhances its thermal stability at 70 °C and 80 °C. Circular dichroism (CD) spectral analysis further indicated that the C-terminal α-helix tail could improve the α-helix content, thus enhancing the structural stability of AcSOD. Thus, a novel C-terminal α-helix tail was firstly discovered, which could confer significant thermal stability to host proteins. This finding provides a new theoretical basis for the study of protein thermostability mechanism.</p></div>","PeriodicalId":793,"journal":{"name":"The Protein Journal","volume":"44 5","pages":"570 - 579"},"PeriodicalIF":1.4,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144669244","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}

引用次数: 0