Biophysical chemistry最新文献_第3页

Hydration parameters (h values) of hydrophobic l-amino acids estimated using the viscosity B-coefficients and partial molar volumes, and the low sensitivity of macromolecular interactions of xanthan gum on the effect of these amino acids in water 利用粘度b系数和偏摩尔体积估算疏水l-氨基酸的水化参数（h值），以及黄原胶的大分子相互作用对这些氨基酸在水中的影响的低敏感性。

IF 2.2 3区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biophysical chemistry

Pub Date : 2026-03-01 Epub Date: 2025-12-04 DOI: 10.1016/j.bpc.2025.107549

Yukinori Sato

Hydration parameter h values of the hydrophobic l-amino acids (l-alanine, l-valine, l-leucine, l-isoleucine, and glycine as a reference) were estimated in water using the viscosity B-coefficients and partial molar volumes, and the food macromolecular interactions were explored in aqueous solutions at 25 °C using the apparent viscosities of macromolecular solutions (polyethylene glycol 3500, dextran T40, guar gum, locust bean gum, apple pectin, citrus pectin, sodium alginate, and xanthan gum) with l-amino acids (l-alanine, l-valine, and glycine as a reference). An increased number of hydrophobic groups were associated with viscosity B-coefficient values, the partial molar volume values, and hydration of approximately 1.4 mol of water per carbon-equivalent. When hydrophobic l-amino acids were added to food macromolecular solutions, the relationship between the apparent viscosity and amino acid molality could be expressed using linear regression lines; the slopes of these lines may reflect macromolecular interactions. Using this novel parameter, the contributions of the hydrophobicity of amino acids to macromolecular interactions can be compared. Glycine decreased and l-valine increased the apparent viscosities of almost all polyelectrolytes (i.e., pectins and alginate) in water, but the effects on nonelectrolytes were less marked (guar gum with glycine is an exception). The effects of l-alanine varied. However, these amino acids did not change the viscosity of xanthan in water, although xanthan is a polyelectrolyte. Thus, the low sensitivity of macromolecular interactions of xanthan gum on the effect of these hydrophobic l-amino acids has been demonstrated to be favorable for use as a stable food thickener.

利用粘度b系数和偏摩尔体积估算了疏水l-氨基酸（l-丙氨酸、l-缬氨酸、l-亮氨酸、l-异亮氨酸和甘氨酸作为参考）在水中的水化参数h值，并利用大分子溶液（聚乙二醇3500、葡聚糖T40、瓜尔胶、槐豆胶、苹果果胶、柑橘果胶、海藻酸钠、瓜尔瓜尔胶）的表观粘度在25°C水溶液中探索了食物大分子相互作用。和黄原胶)与l-氨基酸（l-丙氨酸，l-缬氨酸和甘氨酸作为参考）。疏水基团数量的增加与粘度b系数值、偏摩尔体积值和每碳当量约1.4 mol水的水合作用有关。在食品大分子溶液中加入疏水l-氨基酸，表观粘度与氨基酸摩尔浓度之间的关系可用线性回归曲线表示；这些线的斜率可以反映大分子的相互作用。利用这个新参数，可以比较氨基酸的疏水性对大分子相互作用的贡献。甘氨酸降低和l-缬氨酸增加几乎所有聚电解质（即果胶和海藻酸盐）在水中的表观粘度，但对非电解质的影响不太明显（瓜尔胶与甘氨酸是一个例外）。l-丙氨酸的作用各不相同。然而，这些氨基酸并没有改变黄原胶在水中的粘度，尽管黄原胶是一种聚电解质。因此，黄原胶的大分子相互作用对这些疏水l-氨基酸的影响的低敏感性已被证明有利于作为稳定的食品增稠剂使用。

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引用次数: 0

Biophysical assessment of protein stability in ethanol-stressed environments via UV absorption and fluorescence spectroscopies 利用紫外吸收和荧光光谱对乙醇胁迫环境中蛋白质稳定性的生物物理评价

IF 2.2 3区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biophysical chemistry

Pub Date : 2026-02-01 Epub Date: 2025-10-21 DOI: 10.1016/j.bpc.2025.107538

Erşed Akyüz , Mikhail M. Vorob'ev , Günnur Güler

Maintaining the structure and functionality of proteins is crucial in applications ranging from food preservation to pharmaceutical formulation. Ethanol, while commonly used as a solvent and preservative, can induce structural changes in proteins depending on its concentration and the specific structure of the protein itself. This study investigates the structural effects of ethanol on three types of model proteins, namely bovine serum albumin (BSA), β-Lactoglobulin (β-Lg), and β-Casein (β-Cn), by using UV–Vis spectroscopy and fluorescence spectroscopy. The conformational responses of proteins in water-EtOH solutions of various ethanol concentrations (0–10 %, v/v) were analyzed through absorbance and emission spectral changes. At increasing ethanol concentration, UV absorption data showed distinct protein-dependent spectral changes. β-Lg and β-Cn exhibited strong hypochromism (an absorbance decrease of ∼25 %) and red-shifting at 222 nm and 220 nm, respectively, indicating partial unfolding and solvent exposure of aromatic residues. BSA demonstrated subtle changes, and consistent quenching in fluorescence with a continuous blue-shifting to 330 nm, suggesting a moderate overall stability and local rearrangements in its structure. β-Cn exhibited red-shifted fluorescence and quenching, reflecting its flexible, disordered structure and heterogeneous response to solvent conditions. Statistical analysis revealed that while fluorescence spectroscopy was highly sensitive to the intrinsic differences between proteins (p < 0.001), the ethanol-induced conformational changes were too subtle to be detected as a statistically significant treatment effect. The consistency of these trends indicates a rational underlying mechanism of interaction. This reflects the subtle nature of the effect at the tested concentrations rather than the absence of an effect. Moreover, these results unveil the protein-specific effects of ethanol and strongly emphasize the importance of solvent composition in maintaining protein integrity. Ethanol concentrations up to 5 % may offer protein stability whereas high ethanol levels (≥ 5–10 %) promote structural perturbations. These results will be useful for both basic scientific research, such as biophysical studies and the advancement of optical techniques, and various industrial uses.

维持蛋白质的结构和功能在从食品保存到药物配方的应用中至关重要。乙醇虽然通常用作溶剂和防腐剂，但它可以根据其浓度和蛋白质本身的特定结构引起蛋白质的结构变化。本研究采用紫外可见光谱和荧光光谱技术研究了乙醇对牛血清白蛋白（BSA）、β-乳球蛋白（β-Lg）和β-酪蛋白（β-Cn）三种模型蛋白的结构影响。通过吸收光谱和发射光谱的变化，分析了蛋白质在不同乙醇浓度（0 - 10%,v/v）水溶液中的构象响应。随着乙醇浓度的增加，紫外吸收数据显示出明显的蛋白质依赖性光谱变化。β-Lg和β-Cn分别在222 nm和220 nm处表现出强烈的低色性（吸光度下降约25%）和红移，表明芳香残基部分展开和溶剂暴露。BSA表现出微妙的变化，荧光持续猝灭，连续蓝移至330 nm，表明其整体稳定性中等，结构局部重排。β-Cn表现出红移荧光和猝灭，反映了其柔性、无序结构和对溶剂条件的非均相响应。统计分析显示，虽然荧光光谱对蛋白质之间的内在差异非常敏感（p < 0.001），但乙醇引起的构象变化太微妙，无法作为统计学上显着的治疗效果进行检测。这些趋势的一致性表明了一种合理的潜在相互作用机制。这反映了在测试浓度下影响的微妙性质，而不是没有影响。此外，这些结果揭示了乙醇对蛋白质的特异性作用，并强调了溶剂成分在维持蛋白质完整性方面的重要性。高达5%的乙醇浓度可以提供蛋白质稳定性，而高乙醇水平（≥5 - 10%）会促进结构扰动。这些结果将有助于基础科学研究，如生物物理学研究和光学技术的进步，以及各种工业用途。

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引用次数: 0

Backbone equilibrium in mismatched DNA influenced by solution conditions 溶液条件对错配DNA主链平衡的影响

IF 2.2 3区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biophysical chemistry

Pub Date : 2026-02-01 Epub Date: 2025-10-29 DOI: 10.1016/j.bpc.2025.107548

A. Pilarski , Gary A. Meints

The impact of solution conditions on the ³¹P isotropic chemical shifts of DNA phosphates and therefore the sequence-dependent backbone conformational equilibrium has not been well-documented. There are no previous studies of DNA backbone equilibrium in the presence of crowding agents, nor any on mismatched DNA. A systematic study of several experimental conditions (Na⁺ concentration, K⁺ concentration, Mg²⁺ concentration, pH, the presence of PEG molecular crowders) was performed and the effect quantified in mismatched DNA compared to a canonical control sequence. Na⁺ concentration, pH and crowding agents have only a minimal effect on the backbone equilibrium (<5 % perturbation on backbone populations). But in the mismatched DNA, both K⁺ and Mg²⁺ shift the backbone equilibrium on both DNA strands but most significantly perturb the phosphates in proximity to the mismatch. This indicates a possible role of counterions in mismatch recognition or nucleotide flipping, and suggests knowledge of solutions conditions continue to be relevant for conformational processes.

溶液条件对DNA磷酸盐的31P各向同性化学位移的影响以及序列依赖的主链构象平衡尚未得到充分的证明。以前没有关于拥挤剂存在下的DNA骨架平衡的研究，也没有关于错配DNA的研究。系统研究了几种实验条件（Na+浓度、K+浓度、Mg2+浓度、pH值、PEG分子聚集物的存在），并将错配DNA的影响与标准对照序列进行了量化。钠离子浓度、pH值和拥挤剂对骨架平衡的影响很小（对骨架种群的扰动为5%）。但在错配DNA中，K+和Mg2+都改变了两条DNA链上的主链平衡，但最显著的是干扰了错配DNA附近的磷酸盐。这表明反离子在错配识别或核苷酸翻转中的可能作用，并表明解决条件的知识仍然与构象过程相关。

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引用次数: 0

Development of an EPR-based methodology to study protein-lipid interaction 开发基于epr的方法来研究蛋白质-脂质相互作用。

IF 2.2 3区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biophysical chemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-08 DOI: 10.1016/j.bpc.2025.107550

Clara Piersson , Shikhar Prakash , Victoria Lublin , Melanie Rossotti , Baptiste Fischer , Madhur Srivastava , Yann Fichou

The interaction of protein with other biomolecules is central to all cellular processes. In particular, protein-lipid interactions play an essential role in regulating soluble and membrane protein function, structure, and dynamics. However, probing these interactions remains challenging due to the complexity and heterogeneity of membranes. Various methods have been developed to characterize protein-membrane interaction, each presenting advantages and limitations. This study presents a robust methodology based on continuous-wave Electron Paramagnetic Resonance (CW-EPR) spectroscopy to characterize protein–membrane interactions. We focused on the protein Tau, an intrinsically disordered protein associated with neurodegenerative diseases. We show that the interaction of labelled Tau with lipids gives rise to a very distinct lineshape, which can be used to quantify the fraction of bound protein. This allows to obtain the apparent binding mode and affinity through titration experiments. In addition, we show that a single measurement provides the absolute concentration of free and bound protein. We argue that this information, which is rarely obtained by other methods providing relative signals, is very useful for mechanistic studies. Furthermore, we developed a minimal-data approach and demonstrated that a single EPR measurement can be used to estimate an apparent binding constant. The approach is applied to the Tau-membrane interaction occurring in different conditions affecting the binding behavior. The presented methodology is expected to be applicable to other proteins.

蛋白质与其他生物分子的相互作用是所有细胞过程的核心。特别是，蛋白质-脂质相互作用在调节可溶性和膜蛋白的功能、结构和动力学中起着至关重要的作用。然而，由于膜的复杂性和非均质性，探测这些相互作用仍然具有挑战性。已经开发了各种方法来表征蛋白质-膜相互作用，每种方法都有其优点和局限性。本研究提出了一种基于连续波电子顺磁共振（CW-EPR）光谱的稳健方法来表征蛋白质-膜相互作用。我们专注于Tau蛋白，这是一种与神经退行性疾病相关的内在紊乱蛋白。我们发现标记的Tau与脂质的相互作用产生了非常明显的线形，可以用来量化结合蛋白的比例。这样可以通过滴定实验获得表观结合模式和亲和力。此外，我们表明，一次测量提供了游离和结合蛋白的绝对浓度。我们认为，这一信息，很少得到其他方法提供相对信号，是非常有用的机制研究。此外，我们开发了一种最小数据方法，并证明了单个EPR测量可以用来估计表观结合常数。该方法应用于不同条件下影响结合行为的tau -膜相互作用。所提出的方法有望适用于其他蛋白质。

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引用次数: 0

RufO, a cytochrome P450 (CYP) enzyme, recognition to putative substrates and a redox partner: Binding and structural insights 细胞色素P450 （CYP）酶RufO对假定底物和氧化还原伙伴的识别：结合和结构见解。

IF 2.2 3区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biophysical chemistry

Pub Date : 2026-02-01 Epub Date: 2025-10-26 DOI: 10.1016/j.bpc.2025.107546

Dubey Saniya , Parate Shivani , Suman Abhishek , Vadivelu Abithaa , Priyanka Bajaj , Eerappa Rajakumara

RufO is a Cytochrome P450 enzyme involved in synthesising Rufomycin, a circular peptide with antibacterial activity. Herein, we present structural and biophysical analyses to resolve the ambiguity of RufO's substrate specificity. The structure of unliganded RufO, alongside a series of computational and biophysical studies investigating its substrate specificity in the presence of ferredoxin, which is known to serve as an effector of the redox activities of several P450 enzymes. Contrary to reports on RufO's catalytic activity, monomeric L-tyrosine was not recognized by RufO in our isothermal titration calorimetry (ITC) experiments. Instead, RufO recognizes a range of putative substrates, particularly those containing methyl and nitro groups, suggesting a broader substrate scope. Additionally, we see that RufO binds to its redox partner CamB with micromolar affinity, and its interaction significantly enhances the putative substrate binding by ∼10-fold. Our crystal structure of RufO reveals similarities and differences in putative substrates and ferredoxin binding regions compared to other CYP450 enzymes. Our findings establish RufO might be a substrate-promiscuous enzyme with potential applications in the biocatalytic nitration of industrially relevant compounds.

RufO是一种细胞色素P450酶，参与合成具有抗菌活性的环状肽rufoomycin。在这里，我们提出了结构和生物物理分析来解决RufO底物特异性的模糊性。无配体RufO的结构，以及一系列的计算和生物物理研究，研究了其在铁氧还蛋白存在下的底物特异性，铁氧还蛋白被认为是几种P450酶氧化还原活性的效应物。与有关RufO催化活性的报道相反，在等温滴定量热（ITC）实验中，RufO没有识别单体l -酪氨酸。相反，RufO识别一系列假定的底物，特别是含有甲基和硝基的底物，表明底物范围更广。此外，我们发现RufO以微摩尔亲和力与其氧化还原伙伴CamB结合，其相互作用显著增强了假定的底物结合约10倍。与其他CYP450酶相比，RufO的晶体结构揭示了假定底物和铁氧还蛋白结合区域的异同。我们的研究结果表明，RufO可能是一种底物混杂酶，在工业相关化合物的生物催化硝化中具有潜在的应用前景。

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引用次数: 0

Study of neurotransmitter dopamine interaction with DNA by electrochemical and spectroscopic methods 神经递质多巴胺与DNA相互作用的电化学和光谱研究。

IF 2.2 3区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biophysical chemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-17 DOI: 10.1016/j.bpc.2025.107552

Poghos O. Vardevanyan , Gaspar H. Kocharyan , Marine A. Parsadanyan , Anna V. Vardanyan , Mariam A. Shahinyan , Ara P. Antonyan

Dopamine interaction with DNA has been studied using square-wave voltammetry (SWV), fluorescence, and absorption spectroscopy. The effect of dopamine on the binding of classical intercalating agents, such as acridine orange (AO), ethidium bromide (EtBr) as well as classical groove binding ligand Hoechst 33258 (H33258) was evaluated. The obtained results clarify the molecular mechanisms of dopamine interaction with DNA and reveal its potential competition for intercalation and minor groove binding sites which show that dopamine interacts with DNA by multimodal modes. On the basis of fluorescence measurements, the values of the binding constant (K) and the number of base pairs (n) per binding site were determined. It was revealed that the values of these binding parameters (K and n) depend on the ionic strength of the solution. Based on the changes of the binding parameters of AO, EtBr and H33258 with DNA in the absence and presence of dopamine, it was shown that the presence of the neurotransmitter reduces the affinity of these ligands toward DNA. The obtained data indicate that dopamine binds to DNA via intercalation and minor groove binding mechanisms, which leads to a decrease in the binding constants of these ligands with DNA. In the case of dopamine interaction with DNA in the presence of intercalators, the effect is especially pronounced for the strong (intercalation) binding mode of EtBr, as its binding constant with DNA in the presence of dopamine is significantly lower than that of AO.

利用方波伏安法（SWV）、荧光和吸收光谱研究了多巴胺与DNA的相互作用。评价了多巴胺对经典插层剂如吖啶橙（AO）、溴化乙啶（EtBr）以及经典凹槽结合配体Hoechst 33258 （H33258）结合的影响。研究结果阐明了多巴胺与DNA相互作用的分子机制，揭示了多巴胺与DNA相互作用的嵌入位点和小凹槽结合位点的潜在竞争，表明多巴胺与DNA的相互作用是多模式的。根据荧光测量，确定结合常数(K)和每个结合位点的碱基对数(n)。结果表明，这些结合参数（K和n）的值取决于溶液的离子强度。基于AO、EtBr和H33258在多巴胺缺失和存在情况下与DNA结合参数的变化，表明多巴胺的存在降低了这些配体对DNA的亲和力。所获得的数据表明，多巴胺通过嵌入和小槽结合机制与DNA结合，导致这些配体与DNA的结合常数降低。在多巴胺与插入物存在的DNA相互作用的情况下，EtBr的强（插入）结合模式的影响尤其明显，因为在多巴胺存在的情况下，EtBr与DNA的结合常数明显低于AO。

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引用次数: 0

Structural basis of molecular recognition of pyridoxal 5′-phosphate in a bacterial periplasmic binding protein 细菌周围质结合蛋白中吡哆醛5′-磷酸分子识别的结构基础。

IF 2.2 3区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biophysical chemistry

Pub Date : 2026-02-01 Epub Date: 2025-10-26 DOI: 10.1016/j.bpc.2025.107547

Miriana Quaranta, Stefano Pascarella

Vitamin B₆ and its vitamers are essential in bacteria. Many are auxotrophic for B₆ vitamers and require salvage pathways and membrane uptake systems. Despite the importance of the uptake systems, very few transporters have been structurally characterized. The structure of the periplasmic binding protein (P5PA) of an ABC uptake transporter from the pathogen Actinobacillus pleuropneumoniae has been recently solved in complex with pyridoxal 5′-phosphate (PLP). Another close homolog from the same organism, AfuA, had been structurally characterized as a complex with glucose-6-phosphate (G6P). To study the molecular recognition of PLP by P5PA, a comparative approach has been applied. The heterologous complexes P5PA-G6P and AfuA-PLP have been generated by docking. Systematic molecular dynamics simulations have been applied to the native and heterologous complexes. Binding energies and molecular interactions have been compared for all the complexes. The results suggest the selective binding of the ligand is achieved by a combination of structural factors specific to each protein, including shape of the binding site, steric hindrance, hydrogen bonding, electrostatic and hydrophobic interactions. No single residue is uniquely responsible for ligand specificity although a few side chains play a significant role. Heterologous ligands are subject to destabilizing interactions that provoke the distortion of the ligand itself and the alteration of the protein dynamics. Residue Q267 appears to provide a significant stabilization contribution in the P5PA-PLP complex but not in AfuA-PLP. Likewise, D207 provides stabilization in the AfuA-G6P complex and not in AfuA-PLP. The indications obtained suggest strategies for the design of specific inhibitors.

维生素B6和它的维生素是细菌所必需的。许多是营养不良的维生素B6和需要补救途径和膜摄取系统。尽管摄取系统很重要，但很少有转运体被结构表征。病原体胸膜肺炎放线菌ABC摄取转运体的质周结合蛋白（P5PA）的结构最近与吡哆醛5'-磷酸（PLP）复合物一起解决。来自同一生物体的另一个密切同源物AfuA在结构上被表征为葡萄糖-6-磷酸（G6P）的复合物。为了研究P5PA对PLP的分子识别，我们采用了比较的方法。通过对接生成了异源配合物P5PA-G6P和AfuA-PLP。系统的分子动力学模拟已应用于天然和异种配合物。比较了所有配合物的结合能和分子相互作用。结果表明，配体的选择性结合是由每种蛋白质特异性结构因素的组合实现的，包括结合位点的形状、位阻、氢键、静电和疏水相互作用。虽然有几个侧链起着重要的作用，但没有一个残基是唯一负责配体特异性的。异源配体受到不稳定相互作用的影响，引起配体本身的扭曲和蛋白质动力学的改变。残基Q267似乎在P5PA-PLP复合体中提供了显著的稳定贡献，但在AfuA-PLP中没有。同样，D207对AfuA-G6P复合物起到稳定作用，而对AfuA-PLP不起作用。获得的适应症为设计特异性抑制剂提供了策略。

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引用次数: 0

Sustainable synthesis and functional profiling of Ipomoea hederifolia-derived terpenoids-assisted silver nanoparticles: Mechanistic insights into anticancer, antioxidant, antibiofilm, and anti-quorum sensing activities Ipomoea hederifolia衍生萜类辅助银纳米颗粒的可持续合成和功能分析：抗癌、抗氧化、抗生物膜和抗群体感应活性的机制见解

IF 2.2 3区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biophysical chemistry

Pub Date : 2026-01-01 Epub Date: 2025-09-04 DOI: 10.1016/j.bpc.2025.107524

Khushboo Makwana , Reem Binsuwaidan , Mohd Adnan , Nawaf Alshammari , Mitesh Patel

Silver nanoparticles (AgNPs) synthesized through green chemistry approaches offer a sustainable alternative to conventional methods, with potential applications in various biological fields. In this study, we report the synthesis of AgNPs using terpenoids derived from Ipomoea hederifolia L. (Convolvulaceae). The AgNPs (AgNPs-T) were characterized using UV–Vis spectroscopy, which revealed a surface plasmon resonance (SPR) peak at 452 nm, confirming successful synthesis. Fourier-transform infrared spectroscopy (FTIR) analysis identified functional groups such as hydroxyl and carbonyl that facilitated the reduction of silver ions and acted as stabilizing agents. Transmission electron microscopy (TEM) showed that the AgNPs-T were spherical in shape, with sizes ranging from 4 to 20 nm, and were well-dispersed due to the presence of capping agents from the plant extract. The biological activities of AgNPs-T were evaluated, showcasing potent antibacterial activity against several human pathogenic bacteria. Additionally, AgNPs-T exhibited significant antibiofilm and anti-quorum sensing activities, disrupting biofilm formation and inhibiting bacterial communication. The nanoparticles also demonstrated strong antioxidant properties by scavenging DPPH radicals in a dose-dependent manner. Moreover, cytotoxicity studies using the MTT assay revealed that AgNPs-T exerted dose-dependent anticancer effects against breast cancer (MCF-7) cells. These findings suggest that Ipomoea hederifolia-derived AgNPs possess multifunctional biological activities, making them promising candidates for applications in antimicrobial, antioxidant, and anticancer therapies.

通过绿色化学方法合成银纳米粒子（AgNPs）是一种可持续的替代传统方法的方法，在各种生物领域具有潜在的应用前景。在本研究中，我们报道了利用从旋花科植物中提取的萜类化合物合成AgNPs的方法。利用紫外可见光谱对合成的AgNPs （AgNPs- t）进行了表征，发现在452nm处存在表面等离子体共振峰（SPR），证实了合成成功。傅里叶变换红外光谱（FTIR）分析发现，羟基和羰基等官能团有助于银离子的还原，并起到稳定剂的作用。透射电子显微镜（TEM）显示，AgNPs-T呈球形，大小在4 ~ 20 nm之间，由于植物提取物中的盖层剂的存在，AgNPs-T分散良好。对AgNPs-T的生物活性进行了评价，显示出对几种人类致病菌的强抑菌活性。此外，AgNPs-T表现出显著的抗生物膜和反群体感应活性，破坏生物膜的形成并抑制细菌的交流。纳米颗粒还表现出很强的抗氧化性能，清除DPPH自由基，并呈剂量依赖性。此外，使用MTT试验的细胞毒性研究表明，AgNPs-T对乳腺癌（MCF-7）细胞具有剂量依赖性的抗癌作用。这些发现表明，山茱萸衍生的AgNPs具有多种生物学活性，在抗菌、抗氧化和抗癌治疗方面具有广阔的应用前景。

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引用次数: 0

K2P channels and ultrasound neuromodulation: A mechanosensitive memory perspective K2P通道和超声神经调节：机械敏感记忆的视角

IF 2.2 3区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biophysical chemistry

Pub Date : 2026-01-01 Epub Date: 2025-09-22 DOI: 10.1016/j.bpc.2025.107530

Yuval Ben-Abu

Recent work by Ben Abu and Wolfson introduces the concept of ‘energetic memory’ in ion channels, providing a mechanistic framework for ultrasound neuromodulation. This discussion examines how K2P (two-pore domain potassium) channels serve as primary mediators of mechanosensitive memory due to their small size (0.5 μm radius), constitutive activity, and critical physiological roles. In contrast, larger Kv channels (5 μm) show intermediate sensitivity while Na⁺ channels (50 μm) remain largely unaffected, creating size-dependent responses. Nanoindentor experiments demonstrate sustained membrane hyperpolarization following mechanical compression, validating the theoretical predictions. The energetic memory model explains ultrasound therapy's clinical efficacy through preferential K2P channel compression, energy system adaptation, and prolonged recovery phases. This framework enables rational optimization of therapeutic protocols and extends to other mechanically-based interventions, fundamentally expanding our understanding of neural plasticity beyond traditional electrical mechanisms.

Ben Abu和Wolfson最近的工作介绍了离子通道中“能量记忆”的概念，为超声神经调节提供了一个机制框架。本文探讨了K2P（双孔结构域钾）通道如何由于其小尺寸（0.5 μm半径）、本构活性和关键的生理作用而成为机械敏感记忆的主要介质。相比之下，较大的Kv通道（5 μm）表现出中等灵敏度，而Na+通道（50 μm）基本不受影响，产生尺寸相关的响应。纳米压痕实验证明了机械压缩后膜的持续超极化，验证了理论预测。能量记忆模型通过优先压缩K2P通道、能量系统适应和延长恢复期来解释超声治疗的临床疗效。该框架能够合理优化治疗方案，并扩展到其他基于机械的干预措施，从根本上扩展了我们对传统电机制之外的神经可塑性的理解。

引用次数: 0

Cationic carboxymethyl chitosan nanofibers embedded with silver nanoparticles for enhanced antibacterial applications 嵌入银纳米粒子的阳离子羧甲基壳聚糖纳米纤维增强抗菌应用。

IF 2.2 3区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biophysical chemistry

Pub Date : 2026-01-01 Epub Date: 2025-10-14 DOI: 10.1016/j.bpc.2025.107537

Neha Devi , Satish Kumar Pandey , Nishima Wangoo

There has been a growing concern regarding antibiotic resistance which has led to the design of new antibacterial nanocomposite with high efficiency and low cytotoxicity. This report demonstrates an approach for the design of a nanocomposite comprising of histidine tagged silver nanoparticles (His@AgNPs) embedded it in a carboxymethyl chitosan hydrogel (CHG). Carboxymethyl chitosan was used as a cationic polymer substrate to reinforce the antibacterial activity of the embedded silver nanoparticles. ICP-MS showed sufficient release of silver ions which results in enhanced antibacterial activity. In addition, the hydrogel with embedded silver nanoparticles exhibited excellent antibacterial performance against gram-negative Escherichia coli and gram-positive Staphylococcus aureus through a “kill-release” stratagem, which was mainly due to the synergistic effect of CHG and Ag⁺ ions release. The results showed that the cross-linking may enhance antibacterial activities of nanocomposite (CHG-His@AgNPs) by approximately 4-folds in comparison to His@AgNPs. A strong signal observed in confocal microscopy confirmed the successful internalization of the nanocomposite in tested microorganisms. The change in the morphology of the bacterial cells upon the treatment with nanocomposite was observed through FE-SEM microscopy which confirmed the antibacterial activity of the nanocomposite. The synthesized nanocomposite can thereby serve as an excellent candidate for tackling antibiotic resistance.

人们对抗生素耐药性的关注日益增加，这促使人们设计出高效率、低细胞毒性的新型抗菌纳米复合材料。本报告演示了一种设计纳米复合材料的方法，该纳米复合材料包括将组氨酸标记的银纳米颗粒（His@AgNPs）嵌入羧甲基壳聚糖水凝胶（CHG）中。采用羧甲基壳聚糖作为阳离子聚合物底物，增强银纳米粒子的抗菌活性。ICP-MS显示银离子释放充分，抗菌活性增强。此外，包埋银纳米颗粒的水凝胶对革兰氏阴性大肠杆菌和革兰氏阳性金黄色葡萄球菌表现出优异的抗菌性能，其“杀伤-释放”策略主要是由于CHG和Ag+离子释放的协同作用。结果表明，交联可使纳米复合材料（CHG-His@AgNPs）的抗菌活性比His@AgNPs提高约4倍。在共聚焦显微镜下观察到的强信号证实了纳米复合材料在被测微生物中的成功内化。通过FE-SEM观察了纳米复合材料处理后细菌细胞形态的变化，证实了纳米复合材料的抗菌活性。因此，合成的纳米复合材料可以作为解决抗生素耐药性的极好候选材料。

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