Biophysical chemistry最新文献

{"title":"Cholesterol modulates the interaction of sodium salt with negatively charged phospholipid membrane","authors":"Kalyan Kumar Banerjee,&nbsp;Pabitra Maity,&nbsp;Surajit Das,&nbsp;Sanat Karmakar","doi":"10.1016/j.bpc.2024.107354","DOIUrl":"10.1016/j.bpc.2024.107354","url":null,"abstract":"<div><div>We present a systematic study on how alkali metal salts, like NaCl and NaI, affect negatively charged phospholipid vesicles using a range of experimental methods. Our goal was to find out how chain saturation and cholesterol affect the interaction between the ions and the membrane. An isothermal titration calorimetry study on large unilamellar vesicles made from dimyristoyl phosphatidylcholine (DMPC) revealed that Na⁺ shows higher binding affinity to the gel phase at 15 °C compared to the fluid phase at 30 °C. Further, cations also show stronger affinity to the membrane in the fluid composed of saturated lipids than that of unsaturated lipids. The binding affinity of Na + with anionic vesicles prepared from a mixture of DMPC and DMPG was found to decrease significantly with increasing cholesterol as well as salt concentrations, as revealed by the zeta potential study. Besides the binding constant, the Gouy Chapman theory based on the electrostatic double layer shows that cholesterol reduces the surface charge density without altering the significant area per molecule. Further, the effect of counterions was investigated using fluorescence spectroscopy of an environment-sensitive lipophilic dye, nile red. Although cholesterol alters the emission properties of nile red significantly, there is no significant change in the presence of ions. This result suggests that anions do not bind significantly to anionic vesicles. The main striking feature of the ion-membrane interaction in the presence of cholesterol is that membranes with saturated lipids exhibit a completely opposite trend from membranes with unsaturated lipids.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"317 ","pages":"Article 107354"},"PeriodicalIF":3.3,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142695132","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":"Multispectral analysis and molecular docking of a zinc (II) complex interaction with bovine serum albumin and studies on antibacterial properties, and catecholase mimicry of the complex","authors":"Mohd Tameem ,&nbsp;Mohd Amir ,&nbsp;Mohd Muslim ,&nbsp;Ruby Ahmed ,&nbsp;Mo Ahamad Khan ,&nbsp;Musheer Ahmad ,&nbsp;Farman Ali ,&nbsp;Saleem Javed","doi":"10.1016/j.bpc.2024.107355","DOIUrl":"10.1016/j.bpc.2024.107355","url":null,"abstract":"<div><div>This paper presents the synthesis process of a ligand known as 2-(naphthalene-1-yl)-1H-phenanthro[9,10-d]imidazole (NIP) and its metal complex with zinc (II), denoted as FA-128. The structural validation of FA-128 is accomplished through single-crystal X-ray diffraction (XRD). To explore the biological implications, FA-128's interaction with BSA is investigated. This exploration involves fluorescence and UV–vis absorption spectrometry techniques. The outcomes reveal the formation of robust complexes, as FA-128 significantly quenches the inherent fluorescence of BSA. Various aspects are examined, including binding constants, the count of binding sites, thermodynamic parameters, and energy transfer mechanisms. Evident alterations in BSA conformation are detected using synchronous fluorescence and circular dichroism (CD) spectrum techniques. The study proceeds to molecular docking, elucidating binding sites in the FA-128-BSA interaction. Biochemical reactions between metal complexes and proteins often trigger diverse conformational changes in protein structures. This understanding provides crucial insights into the impacts, mechanisms, and systemic transportation of numerous drugs within the body. FA-128 demonstrated superior antibacterial activity against <em>Staphylococcus aureus</em> (ZOI: 10.50 ± 0.50 mm, MIC: 100 μg/mL) and <em>Klebsiella pneumoniae</em> (ZOI: 13.0 ± 0.25 mm, MIC: 50 μg/mL). In addition, FA-128 has been evaluated as a catalytic system in the oxidation of 3,5-di-tert-butylcatechol (3,5DTBC) in a methanol solvent. FA-128 displays good catecholase-like activity with a significant turnover number (k_cat) of 7.56 × 10² h⁻¹, a Michaelis-Menten constant (K_M) of 8.14 × 10⁻⁴ M, and a maximum reaction rate (V_max) of 2.45 × 10⁻⁵ M s⁻¹ under aerobic conditions.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"317 ","pages":"Article 107355"},"PeriodicalIF":3.3,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142695145","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":"Analysis of solid-state NMR data facilitated by MagRO_NMRViewJ with Graph_Robot: Application for membrane protein and amyloid.","authors":"Naohiro Kobayashi ,&nbsp;Yoshitaka Ishii","doi":"10.1016/j.bpc.2024.107356","DOIUrl":"10.1016/j.bpc.2024.107356","url":null,"abstract":"<div><div>Solid-state NMR (ssNMR) methods have continued to be developed in recent years for the efficient assignment of signals and 3D structure modeling of biomacromolecules. Consequently, we are approaching an era in which vigorous applications of these methods are more widespread in research, including functional elucidation of biomacromolecules and drug discovery. However, multidimensional ssNMR methods are not as advanced as solution NMR methods, especially for automated data analysis. This article describes how a newly developed Graph_Robot module, implemented in MagRO-NMRViewJ, evolved from integrated tools for NMR data analysis named Kujira (developed by Kobayashi et al. [<span><span>1</span></span>]). These packaged tools systematically utilize flexible, sophisticated, yet simple libraries that facilitate only for solution-NMR data analysis, offering an intuitive interface accessible even to novice users. In this study, semi-automated assignments of backbone and side chain signals of ssNMR datasets for uniformly ¹³C/¹⁵N labeled aquaporin Z and 42-residue amyloid-β fibril were examined as examples to demonstrate how Graph_Robot can expedite the visual inspection and handling of multidimensional ssNMR spectral data. In addition, the functionality of the Graph_Robot system enables a computer to interpret the behavior of magnetization transfer based on a finite automaton model.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"318 ","pages":"Article 107356"},"PeriodicalIF":3.3,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142784056","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":"Functional characterization of Staphylococcus aureus lipase 2 (SAL2) as a collagen adhesin","authors":"T. Priyadharshini ,&nbsp;Sreejanani Sankar ,&nbsp;Karthe Ponnuraj","doi":"10.1016/j.bpc.2024.107352","DOIUrl":"10.1016/j.bpc.2024.107352","url":null,"abstract":"<div><div>Extracellular lipases of many pathogens have been characterized as human virulence factors. <em>Staphylococcus aureus</em> produces a variety of enzymes that aid in the pathogenesis of the bacterium to invade and destroy host tissues, resulting in a wide range of clinical illnesses. The lipase is one such enzyme, and the lipases produced by <em>S. aureus</em> (SAL1, SAL2 and SAL3) have been associated with the virulence of the bacterium. In the present study, we cloned, expressed and purified the mature lipase domain of SAL2 (rSAL2₂₉₆_–₆₉₀) and characterized its interaction with human collagen type IV using biolayer interferometry (BLI), molecular docking and simulation studies. Collagen binds to rSAL2₂₉₆_–₆₉₀ with an affinity of 3.261 μM. The enzymatic activity of rSAL2₂₉₆_–₆₉₀ was analyzed in the presence of collagen and orlistat, a potent lipase inhibitor. The activity of rSAL2₂₉₆_–₆₉₀ in the presence of collagen or orlistat was nearly 90 fold lower than that of the native rSAL2₂₉₆_–₆₉₀. The optimal pH and temperature for rSAL2₂₉₆_–₆₉₀ activity were found at 7 and 25 °C respectively. rSAL2₂₉₆_–₆₉₀ found to be stable at pH 7 and exhibits thermostability in the temperature range 15–25 °C. With CaCl₂ and ZnCl₂, an increase in activity of rSAL2₂₉₆_–₆₉₀ was observed whereas NiSO₄, CuSO₄, MnCl₂, CoCl2 and MgCl₂ reduced the activity. No substrate specificity was found with rSAL2₂₉₆_–₆₉₀, as it cleaves different substrate lengths (C2, C6, C12 and C16) and triglyceride triolein. Interaction of rSAL2₂₉₆_–₆₉₀ with metal-incubated collagen revealed that the binding affinity of collagen in the presence of NiSO₄, CuSO₄ and CoCl₂ significantly reduced. Enzymatic and collagen binding studies provided insights into the putative collagen binding site on SAL2₂₉₆_–₆₉₀, which is near the active site region of the molecule. This study thus revealed that rSAL2₂₉₆_–₆₉₀ as a bi-functional molecule, acts not only as a lipase but also as a collagen adhesin.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"317 ","pages":"Article 107352"},"PeriodicalIF":3.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142685942","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":"Elucidating the conformational behavior and membrane-destabilizing capability of the antimicrobial peptide ecPis-4s","authors":"K.R. de Souza ,&nbsp;L.O. Nunes ,&nbsp;E.S. Salnikov ,&nbsp;H.M. Mundim ,&nbsp;V.H.O. Munhoz ,&nbsp;L.M. Lião ,&nbsp;C. Aisenbrey ,&nbsp;J.M. Resende ,&nbsp;B. Bechinger ,&nbsp;R.M. Verly","doi":"10.1016/j.bpc.2024.107353","DOIUrl":"10.1016/j.bpc.2024.107353","url":null,"abstract":"<div><div>Here we present studies of the structure and membrane interactions of ecPis-4 s, a new antimicrobial peptide from the piscidin family, which shows a wide-range of potential biotechnological applications. In order to understand the mode of action ecPis-4 s, the peptide was chemically synthesized and structural investigations in the presence of anionic POPC:POPG (3:1, mol:mol) membrane and SDS micelles were performed. CD spectroscopy demonstrated that ecPis-4 s has a high content of helical structure in both membrane mimetic media, which is in line with solution NMR spectroscopy that revealed an amphipathic helical conformation throughout the entire peptide chain. Solid-state NMR experiments of ecPis-4 s selectively labeled with ¹⁵N/²H and reconstituted into uniaxially oriented POPC:POPG membranes revealed an ideal partition of hydrophilic and hydrophobic residues within the bilayer interface. The peptide aligns in parallel to the membrane surface, a topology stabilized by aromatic side-chain interactions of the Phe-1, Phe-2 and Trp-9 with the phospholipids. ²H NMR experiments using deuterated lipids revealed that anionic lipid accumulates in the vicinity of the cationic peptide upon peptide-membrane binding.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"317 ","pages":"Article 107353"},"PeriodicalIF":3.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142695136","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":"Urineprint of high-altitude: Insights from analyses of urinary biomarkers and bio-physical-chemical features of extracellular vesicles","authors":"Serena Pilato ,&nbsp;Simona Mrakic-Sposta ,&nbsp;Vittore Verratti ,&nbsp;Carmen Santangelo ,&nbsp;Stefano di Giacomo ,&nbsp;Samanta Moffa ,&nbsp;Antonella Fontana ,&nbsp;Tiziana Pietrangelo ,&nbsp;Federica Ciampini ,&nbsp;Sofia Bonan ,&nbsp;Pamela Pignatelli ,&nbsp;Carmine Noce ,&nbsp;Pietro di Profio ,&nbsp;Michele Ciulla ,&nbsp;Danilo Bondi ,&nbsp;Fabrizio Cristiano","doi":"10.1016/j.bpc.2024.107351","DOIUrl":"10.1016/j.bpc.2024.107351","url":null,"abstract":"<div><div>Humans exposed to altitude hypoxia experience dysfunctions of the urinary system. As a non-invasive, easily manageable and informative biological sample, urine represents a relevant matrix for detecting clinical impairments of urinary system, as well as alterations of other systems and extracellular vesicles (EVs) biology during high-altitude expeditions. Nevertheless, gaps exist in the comprehensive assessment of dysfunction, molecular burden and EVs biology due to high-altitude acute exposure. This study aimed to find a biophysical and biochemical signature of urinary EVs for hypoxia-induced changes in urinary function, putatively accompanied by an oxinflammatory burden. Urine samples of 15 participants were sampled at low and high-altitude during an Alpine project (7 women and 8 men, aged 24-to-63 years and with BMI 17.93-to-30.76 kg/m²) and analysed for: creatinin and albumin, lipid peroxidation, IL6, NO derivatives; atomic force microscopy and Raman spectroscopy were carried out after urinary EVs were isolated through sucrose-gradient ultracentrifugation. Albumin-to-creatinin ratio increased at high altitude, as did IL6 and 8-isoprostane. AFM showed a globular and flattened shape of EVs, although several samples were characterized by a lot of contaminants and EVs lost their prototypal spherical shape; EVs comprehensively maintained their morphology at high altitude. Raman spectroscopy revealed some typical phospholipidic-like pattern, often masked by contaminants of spectra that most often refer to high-altitude samples. Collectively, short-term exposure to altitude hypoxia increased renal concentrating ability, produced non-pathological impairment or renal function, and triggered an oxyinflammatory burden with heterogeneous response of NO system. The combination of AFM and Raman spectroscopy revealed that EVs collected at high altitude more likely are fused together and incorporated into a sediment matrix, and contain contaminants peaks that make the purification process less efficient. The combination of analytical procedures as in the present study offers novel possibilities to detect the biological and clinical effects of high altitude on renal system.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"316 ","pages":"Article 107351"},"PeriodicalIF":3.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142647000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetics of i-motif folding within the duplex context","authors":"Rugiya Alieva ,&nbsp;Anna Keshek ,&nbsp;Timofei Zatsepin ,&nbsp;Victor Orlov ,&nbsp;Andrey Aralov ,&nbsp;Elena Zavyalova","doi":"10.1016/j.bpc.2024.107350","DOIUrl":"10.1016/j.bpc.2024.107350","url":null,"abstract":"<div><div>Non-canonical nucleic acid structures possess an ability to interact selectively with proteins, thereby exerting influence over various intracellular processes. Numerous studies indicate that genomic G-quadruplexes and i-motifs are involved in the regulation of transcription. These structures are formed temporarily during the unwinding of the DNA double helix; and their direct determination is a rather difficult task. In addition, i-motif folding is pH-dependent, with most i-motifs having low stability at neutral pH. However, some genomic i-motifs with long cytosine repeats were shown to be stable at pH 7.3, suggesting their functionality within the nucleus. Here we studied pH-dependent behavior of a model i-motif with flanking sequences that forms a duplex motif. Kinetic studies on bimodular structures with cytosine residues replaced with an environment-sensitive fluorescent label reveal the stabilization of the i-motif structure near the i-motif-duplex junction. These results highlight the importance of the natural environment of i-motifs for the correct assessment of their stability.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"316 ","pages":"Article 107350"},"PeriodicalIF":3.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142638345","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":"Supramolecular arrangements in human amyloid tissues using SAXS","authors":"N.S. Mohd Nor Ihsan ,&nbsp;S.F. Abdul Sani ,&nbsp;L.M. Looi ,&nbsp;Dharini Pathmanathan ,&nbsp;P.L. Cheah ,&nbsp;S.F. Chiew ,&nbsp;Sirinart Chio-Srichan ,&nbsp;Siriwat Soontaranon ,&nbsp;D.A. Bradley","doi":"10.1016/j.bpc.2024.107349","DOIUrl":"10.1016/j.bpc.2024.107349","url":null,"abstract":"<div><div>Amyloid diseases are characterized by the accumulation of misfolded protein aggregates in human tissues, pose significant challenges for both diagnosis and treatment. Protein aggregations known as amyloids are linked to several neurodegenerative conditions including Alzheimer's disease, Parkinson's disease, and systemic amyloidosis. The key goal of this research is to employ Small-Angle X-ray Scattering (SAXS) to examine the supramolecular structures of amyloid aggregates in human tissues. We present the structural analysis of amyloid using SAXS, which is employed directly to analyze thin tissue samples without damaging the tissues. This technique provides size and shape information of fibrils, which can be used to generate low-resolution 2D models. The present study investigates the structural changes in amyloid fibril axial d-spacing and scattering intensity in different human tissues, including kidney, heart, thyroid, and others, while also accounting for the presence of triglycerides in these tissues. Tissue structural components were examined at momentum transfer values between q = 0.2 nm⁻¹ and 1.5 nm⁻¹. The d-spacing is a critical parameter in SAXS that provides information about the periodic distances between structures within a sample. From the supramolecular SAXS patterns, the axial d-spacing of fibrils in amyloid tissues is prominent and exists within the 3rd to 10th order, compared to that of healthy tissues which do not have notable peak orders. The axial period of fibrils in amyloid tissues is within the scattering vector range 57.40–64.64 nm⁻¹ while in normal tissues the range is between 60.68 and 61.41 nm⁻¹, which is 3.0 nm⁻¹ smaller than amyloid-containing tissues. Differences in d-spacing are often correlate with distinct pathological mechanisms or stages of disease progression. The application of SAXS to investigate amyloid structures in human tissues has enormous potential to further knowledge of amyloid disorders. This work will open the path for novel diagnostic instruments and therapeutic strategies meant to reduce the burden of amyloid-related diseases by offering a thorough structural examination of amyloid aggregates.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"316 ","pages":"Article 107349"},"PeriodicalIF":3.3,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142638346","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":"Characterization of a novel salt- and solvent-tolerant esterase Dhs82 from soil metagenome capable of hydrolyzing estrogenic phthalate esters","authors":"Yuanyan Wang ,&nbsp;Chunmei Deng ,&nbsp;Xin Wang","doi":"10.1016/j.bpc.2024.107348","DOIUrl":"10.1016/j.bpc.2024.107348","url":null,"abstract":"<div><div>Esterases that can function under extreme conditions are important for industrial processing and environmental remediation. Here, we report the identification of a salt- and solvent-tolerant esterase, Dhs82, from a soil metagenomic library. Dhs82 prefers short-chain <em>p</em>-nitrophenyl (<em>p</em>-NP) esters and exhibits enzymatic activity up to 1460 ± 61 U/mg towards <em>p</em>-NP butyrate. Meanwhile, Dhs82 can catalyze the hydrolysis of dialkyl phthalate esters, especially the widely-used diethyl phthalate (DEP), dipropyl phthalate (DPP) and di-n-butyl phthalate (DBP). Importantly, as an acidic protein with negative charges dominating its surface, Dhs82 is highly active and extraordinarily stable at high salinity. This property is quite rare among previously reported esterases/hydrolases capable of degrading phthalate esters (PAEs). In addition, Dhs82 activity can be significantly enhanced in the presence of solvents over a concentration range of 10–30 % (<em>v</em>/v). Notably, Dhs82 also showed high stability towards these solvents and solvent concentrations as high as 50–60 % (<em>v</em>/v) are required to inactivate Dhs82. Furthermore, molecular docking revealed the key residues, including the catalytic triad (Ser156, His281, and Asp251) and the surrounding Gly84 and Gly85, involved in the interaction of Dhs82 with DBP, depicting how Dhs82 degrades PAEs as a family IV esterase. Together, these diverse properties make Dhs82 a valuable candidate for both basic research and biotechnological applications.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"316 ","pages":"Article 107348"},"PeriodicalIF":3.3,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142614295","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":"The Drosophila RNA binding protein Hrp48 binds a specific RNA sequence of the msl-2 mRNA 3’ UTR to regulate translation","authors":"Andrea Lomoschitz ,&nbsp;Julia Meyer ,&nbsp;Tanit Guitart ,&nbsp;Miroslav Krepl ,&nbsp;Karine Lapouge ,&nbsp;Clara Hayn ,&nbsp;Kristian Schweimer ,&nbsp;Bernd Simon ,&nbsp;Jiří Šponer ,&nbsp;Fátima Gebauer ,&nbsp;Janosch Hennig","doi":"10.1016/j.bpc.2024.107346","DOIUrl":"10.1016/j.bpc.2024.107346","url":null,"abstract":"<div><div>Repression of <em>msl-2</em> mRNA translation is essential for viability of <em>Drosophila melanogaster</em> females to prevent hypertranscription of both X chromosomes. This translational control event is coordinated by the female-specific protein Sex-lethal (Sxl) which recruits the RNA binding proteins Unr and Hrp48 to the 3’ untranslated region (UTR) of the <em>msl-2</em> transcript and represses translation initiation. The mechanism exerted by Hrp48 during translation repression and its interaction with <em>msl-2</em> are not well understood. Here we investigate the RNA binding specificity and affinity of the tandem RNA recognition motifs of Hrp48. Using NMR spectroscopy, molecular dynamics simulations and isothermal titration calorimetry, we identified the exact region of <em>msl-2</em> 3’ UTR recognized by Hrp48. Additional biophysical experiments and translation assays give further insights into complex formation of Hrp48, Unr, Sxl and RNA. Our results show that Hrp48 binds independent of Sxl and Unr downstream of the E and F binding sites of Sxl and Unr to <em>msl-2</em>.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"316 ","pages":"Article 107346"},"PeriodicalIF":3.3,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}