Archives of biochemistry and biophysics最新文献

{"title":"Quercetin enhances muscle FNDC5/irisin, partly through AMPK activation, and induces white adipose tissue browning in high-fat-fed rats","authors":"Victoria Muscia Saez ,&nbsp;Diahann Jeanette Perdicaro ,&nbsp;Cecilia Rodriguez Lanzi ,&nbsp;Eleonora Cremonini ,&nbsp;Patricia Oteiza ,&nbsp;Marcela Alejandra Vazquez Prieto","doi":"10.1016/j.abb.2025.110708","DOIUrl":"10.1016/j.abb.2025.110708","url":null,"abstract":"<div><div>Irisin is a myokine released during physical activity that contributes to the browning of white adipose tissue (WAT), providing various metabolic benefits. We previously demonstrated that supplementation with the flavonoid quercetin (Q) alleviates high-fat diet (HFD) induced visceral WAT hypertrophy, inflammation, and insulin resistance in rats. In this study, we aimed to investigate whether these beneficial effects might be associated with the ability of Q to upregulate muscle fibronectin type 3 domain-containing protein 5 (FNDC5)/irisin and uncoupling protein-1 (UCP-1), along with other brown fat markers in inguinal WAT (iWAT). HFD-fed rats for 6 weeks showed reduced muscle protein levels of FNDC5 and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) compared to the control (Ctrl) group. Q supplementation (20 mg/kg/body weight (BW)/day) reverted these adverse effects of the HFD, significantly increasing muscle p-AMPK as well as plasma irisin levels. Furthermore, Q upregulated key proteins involved in WAT browning (PR domain containing 16 (PRDM16), PGC-1α, PPARɣ and UCP-1) and mitigated HFD-induced iWAT mass gain and hypertrophy. To further investigate the effects of Q on the FNDC5/irisin pathway, L6 myotubes were stimulated with palmitate. Q (1 μM) prevented palmitate-induced decreased levels of p-AMPK and FNDC5, and cell media secreted irisin. Moreover, Q prevented palmitate-mediated decreased Pgc1α and Fndc5 mRNA levels. Transfecting L6 myotubes with Pgc-1α siRNA revealed that Pgc-1α was involved in Q-mediated upregulation of FNDC5. Overall, results show that Q could attenuate HFD-induced iWAT hypertrophy partly through the upregulation of the FNDC5/irisin pathway in muscle and promoting WAT browning. Consumption of Q-rich foods may help mitigate adiposity associated with the consumption of diets rich in saturated fats.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110708"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145779789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LncRNA SNHG6 attenuates ferroptosis in high glucose-treated renal tubular epithelial cells by stabilizing YY1 to activate the PI3K/AKT/GSK-3β pathway","authors":"Qiguo Wang ,&nbsp;Qin Wang ,&nbsp;Xiangyu Meng ,&nbsp;Xiaoman Ji ,&nbsp;Ting Wang","doi":"10.1016/j.abb.2025.110702","DOIUrl":"10.1016/j.abb.2025.110702","url":null,"abstract":"<div><div>Ferroptosis has emerged as a critical mechanism contributing to renal tubular epithelial cell injury in diabetic nephropathy (DN), though its mechanisms require further elucidation. This study investigated the expression and regulatory role of long non-coding RNA small nucleolar RNA host gene 6 (SNHG6) in DN-associated ferroptosis. Bioinformatics analysis confirmed the significant downregulation of SNHG6 in DN and its diagnostic value, while real-time quantitative PCR experiments demonstrated that high glucose treatment for 24 h induced the downregulation of SNHG6 in renal tubular epithelial cells HK-2. Overexpression of SNHG6 alleviated high glucose-triggered ferroptosis of HK-2 cells by promoting the expression of glutathione peroxidase 4 and reducing the expression of acyl-CoA synthetase long chain family member 4 and transferrin receptor, manifested by increased cell viability, decreased lactate dehydrogenase activity, and suppressed lipid peroxidation. Mechanistic studies revealed that SNHG6 stabilized YY1 mRNA by promoting its binding to the FUS RNA-binding protein, subsequently activating the PI3K/AKT/GSK-3β signaling pathway to exert a protective effect. Blocking the YY1-PI3K signaling cascade abolished SNHG6 overexpression-mediated inhibition of high glucose-induced cellular ferroptosis. In summary, SNHG6 exerts renoprotective effects in DN by modulating ferroptosis through the YY1-PI3K/AKT/GSK-3β axis.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110702"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145740661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and reaction mechanisms of a two-component indole monooxygenase from Acinetobacter baumannii","authors":"Kanyarat Suksomjaisaman ,&nbsp;Konrawee Thananon ,&nbsp;Montisa Mangkalee ,&nbsp;Kittisak Thotsaporn ,&nbsp;Ruchanok Tinikul ,&nbsp;Albert Schulte ,&nbsp;Kittikhun Wangkanont ,&nbsp;Supaart Sirikantaramas ,&nbsp;Jeerus Sucharitakul ,&nbsp;Pimchai Chaiyen","doi":"10.1016/j.abb.2025.110681","DOIUrl":"10.1016/j.abb.2025.110681","url":null,"abstract":"<div><div>The indole monooxygenase system from <em>Acinetobacter baumannii</em> is a two-component flavoprotein that catalyzes the monooxygenation of indole. The system consists of the flavoprotein reductase (IndR) and the oxygenase (IndOx). IndR generates reduced FAD (FADH⁻) to IndOx using NADH. The pre-equilibration of IndOx with FADH⁻ inhibits the formation of C4a-hydroperoxyflavin. In contrast, the presence of indole facilitates the formation of C4a-hydroperoxyflavin. The structural study reveals a dynamic loop at the active site, which has never been demonstrated in this class of enzyme, resulting in two conformations of IndOx. The closed conformation prevents the formation of the C4a-hydroperoxyflavin, whereas the binding of indole directs the open conformation, allowing for the formation of C4a-hydroperoxyflavin. The kinetic mechanism of both components was elucidated using rapid kinetics. The binding of indole to form a ternary complex is a preferential random-order mechanism in which indole preferentially binds to IndOx:C4a-hydroperoxyflavin, compared with IndOx:FADH⁻ complex. The turnover number in the presence of both components to produce 3-hydroxyindole demonstrated that either the release of oxidized FAD or the release of monooxygenated product from the IndOx active site, or partially both, entirely limits the catalytic reaction. The solvent isotope effect on the step of the structural rearrangement of the monooxygenated product to form 3-hydroxyindole in this study supports the previously proposed epoxide-dihydrodiol model. This step is significantly slower than the turnover number, indicating that the monooxygenated indole is released and then undergoes a non-enzymatic structural rearrangement outside the active site, leading to the formation of 3-hydroxyindole.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110681"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145653549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"N-terminal KTKEGV motif lysine residues of α-Synuclein are critical for TLR2 interaction and activation","authors":"Krishna Singh Bisht,&nbsp;Manisha Kumari,&nbsp;Tushar Kanti Maiti","doi":"10.1016/j.abb.2025.110701","DOIUrl":"10.1016/j.abb.2025.110701","url":null,"abstract":"<div><div>Synucleinopathies, such as Parkinson's Disease, involve widespread intracellular protein aggregates. α-synuclein (αSyn) protein contributes majorly to these aggregates called as Lewy Bodies, which are linked to neurodegeneration. αSyn has been shown to transmit from infected to healthy neurons, thus spreading the pathology. During its transmission, αSyn is also known to activate microglia by interacting with the glial surface receptors such as Toll-Like receptors (TLRs). This activation is implicated in the production of interleukins and proinflammatory cytokines, exacerbating neuronal death through chronic neuroinflammation. However, the mechanism of αSyn and TLR interaction is not well elucidated. In this study, using biophysical methods and in the HEK-TLR2 cells, we demonstrate that αSyn N-terminal has a higher binding affinity with TLR2. This interaction is mediated through the lysine residues in the second and third KTKEGV motifs of αSyn. The lysine to alanine mutations in the N-terminal KTKGEV motifs perturb the αSyn/TLR2 interaction. We also demonstrate that the lysine residues of 2nd and 3rd KTKEGV motifs are critical for αSyn-mediated TLR2 activation. Our study demonstrates that the N-terminal KTKEGV lysine residues facilitate interaction with TLR2, thereby regulating αSyn-mediated neuroinflammation.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110701"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145740666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An in silico DNA binding investigation using DFT, molecular docking and molecular dynamics simulation on mono and tetra acetylated derivatives of quinalizarin to enable a comparison with experimental DNA binding data","authors":"Tanmoy Saha ,&nbsp;Sayantani Chatterjee ,&nbsp;Saurabh Das","doi":"10.1016/j.abb.2025.110680","DOIUrl":"10.1016/j.abb.2025.110680","url":null,"abstract":"<div><div>Following dissociation of phenolic–OH, quinalizarin generates anions that face repulsion from DNA posing a challenge to its use as an alternative to anthracyclines. An earlier attempt to prevent anion formation by converting all –OH groups to acetyl units had resulted in increased binding with DNA. Although such increase in binding with DNA compared to quinalizarin was observed, owing to a simultaneous increase in steric bulk, a doubt had remained as to whether it was a true manifestation of acetylation. The suspicion being, whether increase in binding constant overcoming repulsion was offset in any way by increase in steric bulk. This <em>in silico</em> DNA binding investigation aims to realize what would be the outcome if one exclusively acetylates the –OH responsible for mono-anion formation. Not having experimental binding information on mono-acetylated species, DNA binding was tried by an <em>in silico</em> approach. Analysis reveals tetra-acetylated quinalizarin was better than the mono-acetylated form; increase due to groove binding, rather than by intercalation being the correct manifestation. Three forms of quinalizarin and the standard drug doxorubicin were investigated by a general DNA model (PDBID:<span><span>1BNA</span><svg><path></path></svg></span>) and subsequently by intercalation specific (PDBID:<span><span>1Z3F</span><svg><path></path></svg></span>) and groove binding specific (PDBID:<span><span>101D</span><svg><path></path></svg></span>) models. ADMET profiles for drug-like properties were done. Information from <em>in silico</em> analysis suggest simpler analogues of anthracyclines are economical and acetylation of all –OH groups of quinalizarin is biologically significant.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110680"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145696006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exosomal miR-4687-5p alleviates silica-induced fibrosis by inhibiting EMT via β-catenin targeting","authors":"Huiyan Qu ,&nbsp;Weidong Xie ,&nbsp;Jing Zhang ,&nbsp;Zhilin Liu ,&nbsp;Shuai Chang ,&nbsp;Fangwei Liu","doi":"10.1016/j.abb.2025.110714","DOIUrl":"10.1016/j.abb.2025.110714","url":null,"abstract":"<div><div>Silicon dioxide (SiO₂) is a major occupational hazard causing irreversible pulmonary fibrosis. While epithelial-mesenchymal transition (EMT) is implicated in fibrosis, its regulation remains unclear. This study identified serum exosomal miR-4687-5p as significantly down-regulated in silicosis patients. Dual-luciferase assays confirmed β-catenin as its direct target. Using the exosome inhibitor GW4869, we demonstrated exosome-mediated transfer of miR-4687-5p from macrophages to lung epithelial cells. Treating epithelial cells with a miR-4687-5p mimic revealed its role in modulating EMT by inhibiting β-catenin nuclear translocation. Crucially, silencing β-catenin in murine lung tissue significantly attenuated silica-induced pulmonary fibrosis. Our findings establish that exosomal miR-4687-5p alleviates silicosis-related fibrosis by targeting β-catenin to suppress EMT, highlighting miR-4687-5p as a potential therapeutic target.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110714"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145826799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial metabolite deoxycholic acid inhibits noncancerous NCM460 human colon cell proliferation: an inverse correlation between Bmal1:Clock gene expression and cell apoptosis","authors":"Huawei Zeng ,&nbsp;Bryan D. Safratowich ,&nbsp;Zhenhua Liu ,&nbsp;Mary Briske-Anderson","doi":"10.1016/j.abb.2025.110694","DOIUrl":"10.1016/j.abb.2025.110694","url":null,"abstract":"<div><div>High fat diets increase colonic deoxycholic acid (DCA) concentrations, which induce apoptosis, and subsequently enrich a compensatory DCA-resistant mutant colon cell subpopulation. While circadian Bmal1 and Clock genes are key regulators for cell proliferation, little is known about the relationship between DCA-induced apoptosis and circadian gene regulation in normal colon cells. In this study, we employed a noncancerous NCM460 human colon cell model to simulate the effect of DCA on cell proliferation in the colon and hypothesized that DCA-induced apoptosis is regulated by the Bmal1Clock complex in colon cells. Compared to the control cells, the treatment with DCA at 0.3- and 0.4-mM inhibited cell proliferation (via cell cycle arrest and apoptosis) by 19 % and 29 %, respectively. As the Bmal1Clock complex and Wnt signaling pathways are interlinked with apoptotic processes, we identified that 42 genes were differentially expressed in the Wnt signaling pathway; and there was a decrease (≥47 %) in Bmal1, Clock and Wee1 protein levels but an increase (≥172 %) in Rev-Erbα protein levels in DCA-treated cells compared to the control cells. At clinical levels, the mRNA levels of Bmal1 and Rev-Erbα were decreased by (≥) 15 % while Wee1 was increased by 38 % in cancerous colon tissues compared to normal ones. Collectively, DCA inhibits noncancerous NCM460 colon cell proliferation via cell cycle arrest and apoptosis accompanied with a drop of Bmal1Clock gene expression and altered Wnt signaling pathways. The Bmal1Clock regulatory network is relatively normal in the DCA-treated noncancerous NCM460 colon cells but not in colon cancer tissues.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110694"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145699396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 multiple mechanisms of Hydroxytyrosol in treating obesity","authors":"Conghui Guan ,&nbsp;Ruilin Han ,&nbsp;Lijuan Liu ,&nbsp;Jinjin Liu ,&nbsp;Songbo Fu ,&nbsp;Xulei Tang","doi":"10.1016/j.abb.2025.110703","DOIUrl":"10.1016/j.abb.2025.110703","url":null,"abstract":"<div><h3>Background</h3><div>The exploration of multi-mechanism therapeutics may represent a key strategy for treating obesity and metabolic dysfunction-associated steatotic liver disease. Hydroxytyrosol (HT), a phenolic compound derived from olive oil in the Mediterranean diet, exhibits potential for obesity treatment; however, its precise mechanisms remain incompletely understood.</div></div><div><h3>Objective</h3><div>This study aimed to elucidate the therapeutic effects of HT in obesity and to uncover its underlying regulatory mechanisms.</div></div><div><h3>Methods</h3><div>An obesity model was induced in C57BL/6 mice via a high-fat diet (HFD) to evaluate the in vivo effects of HT. Assessments included glucose tolerance test (GTT), insulin tolerance test (ITT) and biochemical analyses of fasting blood glucose (FBG), fasting serum insulin (FINS), uric acid (UA), blood lipid, aspartate aminotransferase (AST), and alanine aminotransferase (ALT). Hepatic, skeletal muscle, myocardial and adipose tissue (AT) morphology were examined via H&amp;E staining. In vitro, 3T3-L1 preadipocytes were used to investigate the effects of HT on adipogenesis and thermogenic capacity. Lipid accumulation was assessed by Oil Red O and BODIPY 493/503 staining. Protein expression levels were determined via immunohistochemistry and Western blot analysis.</div></div><div><h3>Results</h3><div>HFD feeding led to increased body weight, FBG, FINS, UA, AST, ALT, and the area under the curve (AUC) for GTT and ITT. H&amp;E staining revealed hepatic vacuolization, skeletal muscle fiber hypertrophy, and myocardial disorganization in HFD-fed mice. HT treatment significantly reduced body weight, improved glucose homeostasis, lipid metabolism, and liver function, and restored normal tissue morphology of liver, skeletal muscle, myocardium, and AT. HFD upregulated the expression of PPARγ, C/EBPβ, FABP4, STING1, and NLRP3 proteins in white AT, which were markedly attenuated by HT. HT reversed HFD-induced downregulation of PGC1α and UCP1 in brown AT. In vitro experiments confirmed that HT modulates adipogenesis and thermogenic activation in preadipocyte via the STING1/NLRP3 pathways.</div></div><div><h3>Conclusion</h3><div>These findings demonstrate that HT acts as a novel anti-obesity agent by targeting the STING1/NLRP3 axis to suppress adipogenesis in adipose tissue and ameliorate obesity-related alterations in AT, liver, skeletal muscle, and myocardium. This study provides a mechanistic foundation for the potential application of HT in obesity intervention.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110703"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145751439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glyceraldehyde-3-phosphate dehydrogenase is inhibited by binding of Cu(I) to the essential active site cysteine","authors":"Gustavo Pelicoli Riboldi ,&nbsp;Samantha J. Firth ,&nbsp;Arnaud Baslé ,&nbsp;Kevin J. Waldron","doi":"10.1016/j.abb.2025.110707","DOIUrl":"10.1016/j.abb.2025.110707","url":null,"abstract":"<div><div>Copper is an essential micronutrient for bacteria, needed for important copper enzymes such as terminal respiratory oxidases. However, in excess, copper is toxic to bacteria. This toxicity is caused by its ability to bind tightly to proteins through the formation of Cu-Cys and Cu-His bonds. To control toxicity, bacteria have evolved homeostatic systems to safely handle the copper they need while efficiently sequestering and effluxing excess copper ions. We previously found that GapA, the abundant glycolytic glyceraldehyde-3-phosphate dehydrogenase enzyme in the <em>Staphylococcus aureus</em> cytosol, becomes associated with copper within cells cultured in medium containing excess copper. We found that this association of GapA with copper resulted in inhibition of its enzyme activity. Here, we have characterised this binding of copper ions to <em>S. aureus</em> GapA <em>in vitro</em> to determine the mechanism of copper inhibition of GapA. We found that purified recombinant GapA binds a single Cu(I) ion with high affinity. Crystallographic structural determination showed association of this copper ion with two active site residues, Cys151 and His178, known to be important for catalysis. This observation was confirmed by characterisation of mutated variants lacking these residues, which showed reduced ability to bind Cu(I) ions. Finally, we demonstrated that the cytosolic copper metallochaperone, CopZ, exhibits a tighter affinity for Cu(I) and can remove copper from GapA <em>in vitro</em>. Together, our data demonstrate the mechanism by which excess copper binds to the <em>S. aureus</em> GapA enzyme and irreversibly inhibit its activity and how the cellular homeostasis system is capable of resolving this inhibition.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110707"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145793148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Staphylococcus aureus sensor histidine kinase VraS mutations linked to antibiotic resistance affect enzymatic catalysis, stability, and substrate interactions","authors":"Brittnee Cagle-White ,&nbsp;Shrijan Bhattarai ,&nbsp;Allison Sunderhaus ,&nbsp;Emerald Scott ,&nbsp;Araceli Solis ,&nbsp;Lane Marsh ,&nbsp;Kristina L. Catague ,&nbsp;Aurijit Sarkar ,&nbsp;May H. Abdel Aziz","doi":"10.1016/j.abb.2025.110715","DOIUrl":"10.1016/j.abb.2025.110715","url":null,"abstract":"<div><div><em>Staphylococcus aureus</em> (<em>S. aureus</em>) is a highly pathogenic bacterium that utilizes the VraSR two-component system to regulate cell wall synthesis and facilitate resistance against antibiotics. Resistant <em>S. aureus</em> isolates were shown to harbor several single-nucleotide polymorphisms in VraS; however, their effect on VraS functionality is not clear. We have investigated the effect of seven mutations in the VraS intracellular domain reported in clinically resistant strains on autophosphorylation rate, stability, and VraS–VraR equilibrium binding affinity (K_D). The expression of wild-type VraS and mutants was optimized, and the proteins were purified using affinity chromatography. A coupled kinase assay was used to assess the autophosphorylation kinetic constants. The stability of the purified proteins was assessed using differential scanning fluorimetry, and surface plasmon resonance was used to measure the K_D of the constructs to VraR. The results show that several mutations enhanced the catalytic efficiency of VraS and led to an increase in protein stability. All the mutants retained the same affinity to VraR as the wild type, except D242G, which showed a 17-fold decrease in affinity. Molecular dynamics simulation of a generated dimeric VraS homology model shows that the M192I mutant may have an increased possibility of forming the Michaelis complex. This study investigated the effect of VraS mutations on the enzymatic activity, stability, and affinity to its cognate response regulator, which can translate to a modified bacterial response to stress. The results highlight the importance of studying bacterial kinase mutations as an underlying mechanism of antibiotic resistance in <em>S. aureus.</em></div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110715"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}