Protein Aggregates

蛋白质聚集体
  • 文章类型: Journal Article
    本研究探讨了微波(MW)场下l-赖氨酸干预小麦面筋蛋白(WG)凝胶形成的机理。结果表明,在相同的升温速率下,MW处理具有较高的ζ电位值。加入L-赖氨酸后,溶液电导率和介电损耗显著增加。此外,在MW处理下,WG凝胶强度提高了4.40%。傅里叶光谱显示,随着赖氨酸的加入,α-螺旋含量降低了13.78%。紫外吸收光谱和荧光光谱表明,MW辐射比水浴加热更有效地影响WG分子之间的相互作用。促进蛋白质结构的变性和展开。此外,扫描电镜分析表明,赖氨酸的掺入促进了蛋白质有序网络结构的形成,这增强了凝胶特性。这表明1-赖氨酸的两性离子在MW场中蛋白质的聚集中起调节作用。
    This study explored the mechanism of l-lysine intervention in wheat gluten protein (WG) gel formation under a microwave (MW) field. The results showed that the MW treatment had higher ζ-potential values at the same heating rate. After adding l-lysine, the solution conductivity and dielectric loss were significantly increased. Moreover, the WG gel strength enhanced 4.40% under the MW treatment. The Fourier spectra showed that the α-helix content was decreased 13.78% with the addition of lysine. The ultraviolet absorption spectra and fluorescence spectra indicated that MW irradiation impacted the interactions between WG molecules more effectively than the water bath heating, promoting the denaturation and unfolding of the protein structure. In addition, scanning electron microscopy analysis showed that the incorporation of lysine promoted an ordered network structure formation of the protein, which enhanced the gel properties. This indicated that the zwitterion of l-lysine played a regulatory role in the aggregation of proteins in the MW field.
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  • 文章类型: Journal Article
    大脑和胰腺中淀粉样蛋白β(Aβ)和人胰岛淀粉样多肽(hIAPP)的共存与阿尔茨海默病(AD)和2型糖尿病(T2D)的风险增加有关,这是由于它们的共同聚集和交叉接种。尽管如此,它们相互作用的分子机制仍然难以捉摸。这里,我们使用原子离散分子动力学(DMD)模拟系统地研究了Aβ和hIAPP之间的串扰。我们的结果表明,Aβ(Aβ10-21和Aβ30-41)和hIAPP(hIAPP8-20和hIAPP22-29)的淀粉样蛋白形成核心区,推动他们的自我聚集,也表现出强烈的交叉相互作用趋势。这种倾向导致形成富含β-折叠的杂复合物,包括潜在有毒的β桶低聚物。Aβ和hIAPP异质聚集体的形成不妨碍募集另外的肽以生长为更大的聚集体。我们的交叉播种模拟表明,Aβ和hIAPP原纤维可以相互充当种子,协助彼此的单体在暴露的原纤维伸长末端转化为β-折叠。Aβ和hIAPP的淀粉样蛋白形成核心区,在寡聚和纤维状状态下,表现出募集分离肽的能力,从而延伸β-折叠边缘,对氨基酸序列的敏感性有限。这些发现表明,通过用淀粉样蛋白抗性肽药物覆盖这些区域,可能具有作为解决AD的治疗方法的潜力。T2D,和他们的共形病理学。
    The coexistence of amyloid-β (Aβ) and human islet amyloid polypeptide (hIAPP) in the brain and pancreas is associated with an increased risk of Alzheimer\'s disease (AD) and type 2 diabetes (T2D) due to their coaggregation and cross-seeding. Despite this, the molecular mechanisms underlying their interaction remain elusive. Here, we systematically investigated the cross-talk between Aβ and hIAPP using atomistic discrete molecular dynamics (DMD) simulations. Our results revealed that the amyloidogenic core regions of both Aβ (Aβ10-21 and Aβ30-41) and hIAPP (hIAPP8-20 and hIAPP22-29), driving their self-aggregation, also exhibited a strong tendency for cross-interaction. This propensity led to the formation of β-sheet-rich heterocomplexes, including potentially toxic β-barrel oligomers. The formation of Aβ and hIAPP heteroaggregates did not impede the recruitment of additional peptides to grow into larger aggregates. Our cross-seeding simulations demonstrated that both Aβ and hIAPP fibrils could mutually act as seeds, assisting each other\'s monomers in converting into β-sheets at the exposed fibril elongation ends. The amyloidogenic core regions of Aβ and hIAPP, in both oligomeric and fibrillar states, exhibited the ability to recruit isolated peptides, thereby extending the β-sheet edges, with limited sensitivity to the amino acid sequence. These findings suggest that targeting these regions by capping them with amyloid-resistant peptide drugs may hold potential as a therapeutic approach for addressing AD, T2D, and their copathologies.
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  • 文章类型: Journal Article
    载体的表面化学在酶负载能力中起着关键作用,结构刚度,从而催化固定化酶的活性。在这项工作中,将辣根过氧化物酶(HRP)和葡萄糖氧化酶(GOx)这两种模型酶共固定在溶菌酶功能化的磁性核壳纳米复合材料(LYZ@MCSNC)上,以增强其稳定性和活性。简而言之,HRP和GOx聚集体首先在均苯三酸的交联剂下形成,其中可以进一步增加酶的负载量和刚性。此外,LYZ很容易在SiO2@Fe3O4磁性纳米粒子表面形成坚固的抗生物污染的纳米薄膜,具有丰富的官能团,其促进HRP和GOx聚集体的化学交联,同时具有最小化的失活。HRP-GOx@LYZ@MCSNCs的固定化酶表现出比游离酶(HRP&GOx)高的优异的恢复活性(95.6%)。具体来说,在7个周期后保留了85%的相对活性,而在4°C下储存33天后还保留了73.5%的初始活性。HRP-GOx@LYZ@MCSNCs的热稳定性和pH适应性均优于HRP&GOx的游离酶。这项研究为使用HRP和GOx作为模型酶的基于LYZ功能化磁性纳米颗粒的多酶共固定提供了一种温和且生态的策略。
    Surface chemistry of carriers plays a key role in enzyme loading capacity, structure rigidity, and thus catalyze activity of immobilized enzymes. In this work, the two model enzymes of horseradish peroxidase (HRP) and glucose oxidase (GOx) are co-immobilized on the lysozyme functionalized magnetic core-shell nanocomposites (LYZ@MCSNCs) to enhance their stability and activity. Briefly, the HRP and GOx aggregates are firstly formed under the crosslinker of trimesic acid, in which the loading amount and the rigidity of the enzyme can be further increased. Additionally, LYZ easily forms a robust anti-biofouling nanofilm on the surface of SiO2@Fe3O4 magnetic nanoparticles with abundant functional groups, which facilitate chemical crosslinking of HRP and GOx aggregates with minimized inactivation. The immobilized enzyme of HRP-GOx@LYZ@MCSNCs exhibited excellent recovery activity (95.6 %) higher than that of the free enzyme (HRP&GOx). Specifically, 85 % of relative activity was retained after seven cycles, while 73.5 % of initial activity was also remained after storage for 33 days at 4 °C. The thermal stability and pH adaptability of HRP-GOx@LYZ@MCSNCs were better than those of free enzyme of HRP&GOx. This study provides a mild and ecofriendly strategy for multienzyme co-immobilization based on LYZ functionalized magnetic nanoparticles using HRP and GOx as model enzymes.
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  • 文章类型: Case Reports
    GATM相关的Fanconi肾小管综合征1(FRTS1)是肾性Fanconi综合征(RFS)的一种形式,这是由于整个近端小管的功能缺陷引起的溶质和水分重吸收的紊乱。最近的发现揭示了FRTS1的分子基础:由突变型GATM触发的线粒体内纤维聚集为近端小管损伤提供了起点并驱动疾病进展。作为一种罕见的新发现的遗传性肾病,FRTS1的复杂表现容易漏诊或误诊。我们讨论了一名26岁女性的复杂表型,该女性在婴儿期发病,并且有很长的低磷酸盐血症病病史。我们还在该患者的GATM基因中鉴定了一种新的杂合错义变体。我们报告的新变体和表型扩展了FRTS1的疾病谱。我们建议对患有RFS的儿童进行GATM筛查,尤其是以前基因检测呈阴性的抗性病患者。此外,我们通过电子显微镜和免疫荧光的结合发现了患者尿沉渣细胞线粒体内突变GATM蛋白的病理性沉积。这种独特的尿液细胞学实验有可能成为识别RRTS1患者的有价值的工具。
    GATM-related Fanconi renotubular syndrome 1 (FRTS1) is a form of renal Fanconi syndrome (RFS), which is a disorder of solute and water reabsorption caused by defects in the function of the entire proximal tubule. Recent findings reveal the molecular basis of FRTS1: Intramitochondrial fiber aggregation triggered by mutant GATM provides a starting point for proximal tubule damage and drives disease progression. As a rare and newly recognized inherited kidney disease, the complex manifestations of FRTS1 are easily underdiagnosed or misdiagnosed. We discuss the complex phenotype of a 26-year-old woman with onset in infancy and a long history of hypophosphatemic rickets. We also identified a novel heterozygous missense variant in the GATM gene in this patient. The novel variant and phenotype we report expand the disease spectrum of FRTS1. We recommend screening for GATM in children with RFS, especially in patients with resistant rickets who have previously had negative genetic testing. In addition, we found pathological deposition of mutant GATM proteins within mitochondria in the patient\'s urinary sediment cells by a combination of electron microscopy and immunofluorescence. This unique urine cytology experiment has the potential to be a valuable tool for identifying patients with RRTS1.
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  • 文章类型: Journal Article
    为抵制日益严重的水污染,净化水源,废水处理材料是必不可少的。特别是,必须提高吸附材料与基材在长期潮湿环境中的结合强度,并抵抗微生物的入侵,延长使用寿命。在这项研究中,由微生物转谷氨酰胺酶(mTGase)催化的溶菌酶的淀粉样聚集方法。溶菌酶在还原剂的存在下自我组装成淀粉样蛋白样相变溶菌酶(PTL)。同时,mTGase催化溶菌酶分子内或溶菌酶和角蛋白分子之间的酰基转移反应,和在羊毛纤维上驱动PTL组件(TG-PTL@羊毛)。该方法提高了PTL在羊毛上的接枝量和牢度。此外,羊毛织物的拉伸强度提高到523N。TG-PTL@羊毛对重金属的去除率达到97.32%,5次循环后保持95%以上的去除率。TG-PTL@羊毛具有优异的抗菌性能(99%),经过50次循环洗涤后,它保持在90%以上。本研究证明mTGase可以增强溶菌酶的淀粉样聚集,并增强PTL涂层与基底之间的结合强度。此外,TG-PTL@羊毛提供了一个可持续的,从水中去除重金属的有效和清洁的解决方案。
    To counteract the increasing severity of water pollution and purify water sources, wastewater treatment materials are essential. In particular, it is necessary to improve the bonding strength between the adsorption material and the substrate in a long-term humid environment, and resist the invasion of microorganisms to prolong the service life. In this study, an amyloid-like aggregation method of lysozyme catalyzed by microbial transglutaminase (mTGase). Lysozyme self-assembles into an amyloid-like phase-transited lysozyme (PTL) in the presence of a reducing agent. Simultaneously, mTGase catalyzes acyl transfer reactions within lysozyme molecules or between lysozyme and keratin molecules, and driving PTL assembly on the wool fiber (TG-PTL@wool). This process enhances the grafting amount and fastness of PTL on the wool. Moreover, the tensile strength of wool fabric increased to 523 N. TG-PTL@wool achieves a 97.32 % removal rate of heavy metals, maintaining a removal rate of over 95 % after 5 cycles. TG-PTL@wool has excellent antibacterial property (99 %), and it remains above 90 % after 50 times of circulating washing. This study proved that mTGase can enhance the amyloid aggregation of lysozyme and enhance the bonding strength between PTL coating and substrate. Moreover, TG-PTL@wool provides a sustainable, efficient and cleaner solution for removing heavy metals from water.
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  • 文章类型: Journal Article
    大豆蛋白基产品的质地主要受蛋白质的聚集和凝胶形态的影响,这是由制造因素调节的。参与蛋白质形态变化的相互作用包括二硫键,疏水相互作用,静电相互作用,和氢键。值得注意的是,相互作用的观点可能为解释聚集和凝胶形态提供了一种新的方法,这可以帮助克服开发质感产品的障碍。基于交互的视角,这篇综述提供了关于汇总的详细信息和证据,构象稳定性,pH诱导大豆蛋白及其组分的凝胶网络形态,NaCl,和温度。pH引起的静电相互作用和氢键,NaCl诱导的静电相互作用,和温度诱导的疏水相互作用和二硫键是导致大豆聚集和凝胶形态变化的主要动机。通过减少强相互作用的比例,如二硫键和疏水相互作用,增加弱相互作用的比例,如静电相互作用和氢键,蛋白质总表面积扩大,表明构象拉伸增加,内聚力降低。这可能导致纹理蛋白质的硬度降低和韧性增加。当强相互作用的比例增加而弱相互作用的比例降低时,可以观察到相反的效果。
    The texture of soybean protein-based products is primarily influenced by the aggregation and gel morphology of the protein, which is modulated by manufacturing factors. Interactions involved in protein morphology changes include disulfide bonds, hydrophobic interactions, electrostatic interactions, and hydrogen bonds. Notably, an interaction perspective probably provides a new way to explaining the aggregation and gel morphology, which could help overcome the hurdle of developing a textured product. Based on the interaction perspective, this review provides detailed information and evidence on aggregation, conformational stability, and gel network morphology of soybean protein and its components induced by pH, NaCl, and temperature. pH-induced electrostatic interactions and hydrogen bonds, NaCl-induced electrostatic interactions, and temperature-induced hydrophobic interactions and disulfide linkages are the main motivations responsible for changes in soybean aggregation and gel morphology. By reducing the proportion of strong-interactions, such as disulfide linkages and hydrophobic interactions, and increasing the proportion of weak-interactions, such as electrostatic interactions and hydrogen bonds, the protein total surface area expands, indicating increased conformational stretching and decreased cohesion. This possibly results in reduced hardness and increased toughness of textured proteins. The opposite effect can be observed when the proportion of strong interactions is increased and that of weak interactions is decreased.
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  • 文章类型: Journal Article
    淀粉样β(Aβ)肽的积累是阿尔茨海默病(AD)的主要标志,在其发病机制中起着至关重要的作用。特别是,富含β-折叠形成的结构化寡聚物种与神经元细胞器损伤有关。解决这种强大的挑战需要鉴定能够抑制肽聚集或解聚预先形成的寡聚体的候选物,用于有效的基于抗聚集的AD治疗。这里,我们提出了一种精心设计的双功能纳米抑制剂,以靶向聚集驱动力和淀粉样蛋白原纤维空间结构。利用内面体金属富勒烯Gd@C82的卓越结构稳定性和简易剪裁能力,我们引入了所需的氢结合位点和带电基团,它的表面上有丰富的特定设计。令人印象深刻的是,这些设计赋予所得的功能化-Gd@C82纳米颗粒(f-Gd@C82NP)具有将肽自组装向无序重定向的高能力,偏离途径的物种,阻碍了原纤维的早期生长,并分解预先形成的有序原纤维或甚至成熟的Aβ原纤维。这导致Aβ肽诱导的神经元细胞毒性的显著缓解,在原代神经元模型中拯救神经元死亡和突触丢失。值得注意的是,这些修饰显著提高了f-Gd@C82NP的分散性,从而大大提高了其生物利用度。此外,f-Gd@C82NP显示出与各种细胞系的优异细胞相容性,并且具有穿透小鼠血脑屏障的能力。大规模分子动力学模拟阐明了抑制和解聚机制。我们的设计成功地克服了其他纳米盐的局限性,通常过度依赖疏水相互作用或光热转化特性,并通过抑制甚至逆转Aβ聚集为开发抗AD药物提供了可行的方向。
    The accumulation of amyloid-β (Aβ) peptides is a major hallmark of Alzheimer\'s disease (AD) and plays a crucial role in its pathogenesis. Particularly, the structured oligomeric species rich in β-sheet formations were implicated in neuronal organelle damage. Addressing this formidable challenge requires identifying candidates capable of inhibiting peptide aggregation or disaggregating preformed oligomers for effective antiaggregation-based AD therapy. Here, we present a dual-functional nanoinhibitor meticulously designed to target the aggregation driving force and amyloid fibril spatial structure. Leveraging the exceptional structural stability and facile tailoring capability of endohedral metallofullerene Gd@C82, we introduce desired hydrogen-binding sites and charged groups, which are abundant on its surface for specific designs. Impressively, these designs endow the resultant functionalized-Gd@C82 nanoparticles (f-Gd@C82 NPs) with high capability of redirecting peptide self-assembly toward disordered, off-pathway species, obstructing the early growth of protofibrils, and disaggregating the preformed well-ordered protofibrils or even mature Aβ fibrils. This results in considerable alleviation of Aβ peptide-induced neuronal cytotoxicity, rescuing neuronal death and synaptic loss in primary neuron models. Notably, these modifications significantly improved the dispersibility of f-Gd@C82 NPs, thus substantially enhancing its bioavailability. Moreover, f-Gd@C82 NPs demonstrate excellent cytocompatibility with various cell lines and possess the ability to penetrate the blood-brain barrier in mice. Large-scale molecular dynamics simulations illuminate the inhibition and disaggregation mechanisms. Our design successfully overcomes the limitations of other nanocandidates, which often overly rely on hydrophobic interactions or photothermal conversion properties, and offers a viable direction for developing anti-AD agents through the inhibition and even reversal of Aβ aggregation.
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  • 文章类型: Journal Article
    人们普遍认为,热处理可以增强蛋白质的胃消化,这主要是基于动物蛋白质的发现,可能不适用于所有蛋白质。特别是植物蛋白。这里,我们在体外半动态消化模型中比较了大豆分离蛋白(SPI)的消化特性,发现热处理对植物蛋白的消化特性有明显影响。结果表明,热处理的SPIs在消化的早期阶段形成凝块,尽管随着消化的进展,凝块逐渐变小和变松,系统在胃消化结束时仍然混浊,表明它们排空的滞后。此外,热处理改变了SPI的流变特性,导致粘度增加和胃排空减慢。这些效果随着热处理温度的升高而变得更加明显。荧光光谱分析表明,热处理改变了其构象。这导致蛋白质展开和疏水基团的暴露,促进消化过程中形成较大的聚集体。此外,热处理暴露更多的裂解位点的胃蛋白酶,增加水解程度。游离氨基酸水平的升高和较小的分子量分布进一步证实了这些发现。这些发现有助于更深入地了解植物蛋白的胃消化特性以及蛋白聚集结构与消化过程之间的关系。
    The common belief that heat treatment enhances the gastric digestion of proteins is largely based on findings from animal proteins and may not apply to all proteins, particularly plant proteins. Here, we compared the digestion characteristics of soybean protein isolates (SPI) in an in vitro semi-dynamic digestion model and found distinct effects of heat treatment on the digestion properties of plant proteins. The results revealed that heat-treated SPIs formed clots during the early stages of digestion, although the clots gradually became smaller and looser as digestion progressed, the systems remained turbid at the end of gastric digestion, indicating the lag in their emptying. Furthermore, heat treatment altered the rheological properties of SPI, resulting in increased viscosity and slower gastric emptying. These effects became more pronounced with increasing heat treatment temperatures. The fluorescence spectrum analysis indicated that heat treatment altered its conformation. This led to protein unfolding and exposure of hydrophobic groups, facilitating the formation of larger aggregates during digestion. Additionally, heat treatment exposed more cleavage sites for gastric proteases, increasing the extent of hydrolysis. Elevated levels of free amino acids and a smaller molecular weight distribution further corroborated these findings. These findings contribute to a deeper understanding of the gastric digestion characteristics of plant proteins and the relationship between protein aggregation structure and the digestion process.
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  • 文章类型: Journal Article
    α-突触核蛋白(α-Syn)在路易体中的沉积是帕金森病(PD)的突出病理标志。最近的研究表明,α-Syn在其纤维化过程中可以进行液-液相分离(LLPS)。随着时间的推移,所得缩合物的成熟导致液-固相变(LSPT),最终导致淀粉样蛋白在细胞中沉积,这与PD的发病机理和发展有关。在这里,我们总结了对α-Syn聚集的理解,可以通过成核和延伸步骤来描述,以了解蛋白质聚集的相关性,结构多态性,和PD进展。此外,我们讨论了α-Syn和异型交叉淀粉样蛋白相互作用的LLPS现象,重点是聚集过程中的异常LSPT。探索α-Syn异常聚集之间的潜在机制和相互作用,病理相变,PD的发病机制将揭示潜在的治疗干预措施。
    The deposition of α-synuclein (α-Syn) in Lewy bodies serves as a prominent pathological hallmark of Parkinson\'s disease (PD). Recent research has revealed that α-Syn can undergo liquid-liquid phase separation (LLPS) during its fibrillization. Over time, the maturation of the resulting condensates leads to a liquid-to-solid phase transition (LSPT) ultimately resulting in the amyloid deposition in cells which is linked to the pathogenesis and development of PD. Herein, we summarize the understanding of α-Syn aggregation which can be described by nucleation and elongation steps to obtain insights into the correlation of protein aggregation, structural polymorphism, and PD progression. Additionally, we discuss the LLPS phenomena of α-Syn and heterotypic cross-amyloid interactions with a focus on aberrant LSPT in the aggregation process. Exploring the underlying mechanisms and interplay between α-Syn aberrant aggregation, pathological phase transitions, and PD pathogenesis will shed light on potential therapeutic interventions.
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  • 文章类型: Journal Article
    由于体感神经系统损伤或疾病,神经性疼痛通常与化疗有关,称为化疗引起的周围神经病变(CIPN)。然而,由于检测手段有限,CIPN诱导的神经元细胞蛋白质组聚集的机制仍然难以捉摸.在这里,我们提供了用于荧光成像(AggStain)和蛋白质组学分析(AggLink)的系列传感器,以可视化和捕获CIPN神经元细胞模型中聚集的蛋白质组。环境敏感的AggStain成像传感器选择性结合并检测具有12.3倍荧光增强的蛋白质聚集。Further,共价AggLink蛋白质组传感器通过LC-MS/MS分析捕获细胞聚集的蛋白质并描述其组成。该集成传感器平台揭示了CIPN细胞模型中蛋白质组聚集的存在,并强调了其在各种细胞应激条件下评估蛋白质组稳定性的更广泛应用的潜力。
    As a consequence of somatosensory nervous system injury or disease, neuropathic pain is commonly associated with chemotherapies, known as chemotherapy-induced peripheral neuropathy (CIPN). However, the mechanisms underlying CIPN-induced proteome aggregation in neuronal cells remain elusive due to limited detection tools. Herein, we present series sensors for fluorescence imaging (AggStain) and proteomics analysis (AggLink) to visualize and capture aggregated proteome in CIPN neuronal cell model. The environment-sensitive AggStain imaging sensor selectively binds and detects protein aggregation with 12.3 fold fluorescence enhancement. Further, the covalent AggLink proteomic sensor captures cellular aggregated proteins and profiles their composition via LC-MS/MS analysis. This integrative sensor platform reveals the presence of proteome aggregation in CIPN cell model and highlights its potential for broader applications in assessing proteome stability under various cellular stress conditions.
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