cytochrome

细胞色素
  • 文章类型: Journal Article
    目的:安乃近是一种相当古老的镇痛药,解热和痉挛特性。最近的研究结果表明,它可以诱导几种细胞色素P450(CYP)酶,尤其是CYP3A4和CYP2B6。这些特性的临床相关性是不确定的。我们的目的是揭示安乃近和CYP3A4底物喹硫平之间潜在的药代动力学相互作用。
    方法:分析了来自大型治疗药物监测数据库的喹硫平的血浆浓度。两组33例,要么接受喹硫平作为单一疗法(无CYP调节粉刺),要么同时应用安乃近,我们进行了比较,发现美乃唑对喹硫平代谢的潜在影响反映在喹硫平的血浆浓度和剂量调整后的血浆浓度的差异上。
    结果:服用安乃近的患者显示喹硫平的血浆浓度降低>50%(中位数为45.2ng/mL,Q1=15.5;Q3=90.5vs.92.0ng/mL,Q1=52.3;Q3=203.8,P=.003)。剂量调整后的血浆浓度在昏迷组降低了69%(P=.001)。亚组分析未表明安乃近效应或喹硫平制剂的影响存在剂量依赖性(立即与延长释放)。最后,在喹硫平浓度低于治疗参考范围的患者中,昏迷组表现出明显更高的比例(安乃近组78.8%与对照组54.4%,P=0.037)表示治疗药物浓度不足。
    结论:安乃近和喹硫平合用导致喹硫平的药物浓度明显降低,可能是通过CYP3A4的诱导。临床医生必须考虑药物不良反应的风险,特别是在喹硫平下加入安乃近时治疗失败。
    OBJECTIVE: Metamizole is quite an old drug with analgesic, antipyretic and spasmolytic properties. Recent findings have shown that it may induce several cytochrome P450 (CYP) enzymes, especially CYP3A4 and CYP2B6. The clinical relevance of these properties is uncertain. We aimed to unravel potential pharmacokinetic interactions between metamizole and the CYP3A4 substrate quetiapine.
    METHODS: Plasma concentrations of quetiapine from a large therapeutic drug monitoring database were analysed. Two groups of 33 patients, either receiving quetiapine as a monotherapy (without CYP modulating comedications) or with concomitantly applied metamizole, were compared addressing a potential impact of metamizole on the metabolism of quetiapine being reflected in differences of plasma concentrations of quetiapine and dose-adjusted plasma concentrations.
    RESULTS: Patients comedicated with metamizole showed >50% lower plasma concentrations of quetiapine (median 45.2 ng/mL, Q1 = 15.5; Q3 = 90.5 vs. 92.0 ng/mL, Q1 = 52.3; Q3 = 203.8, P = .003). The dose-adjusted plasma concentrations were 69% lower in the comedication group (P = .001). Subgroup analyses did not suggest a dose dependency of the metamizole effect or an influence of quetiapine formulation (immediate vs. extended release). Finally, the comedication group exhibited a significantly higher proportion of patients whose quetiapine concentrations were below the therapeutic reference range (78.8% in the metamizole group vs. 54.4% in the control group, P = .037) indicating therapeutically insufficient drug concentrations.
    CONCLUSIONS: The combination of metamizole and quetiapine leads to significantly lower drug concentrations of quetiapine, probably via an induction of CYP3A4. Clinicians must consider the risk of adverse drug reactions, especially treatment failure under quetiapine when adding metamizole.
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  • 文章类型: Journal Article
    胶质细胞通过分泌可溶性因子为神经元和神经组织的细胞外区室提供物理和化学支持和保护。不溶性支架,和囊泡。此外,神经胶质细胞通过重塑其物理微环境和改变其附近不同细胞类型的生理特性而具有再生能力。各种类型的异常胶质细胞和巨噬细胞与人类疾病有关,障碍,和恶性肿瘤。我们以前证明了跨膜蛋白,TMEM230通过分泌促血管生成因子和金属蛋白酶而具有组织血运重建和再生能力,诱导内皮细胞发芽和通道形成。在健康的正常神经组织中,TMEM230主要表达于神经胶质细胞和细胞中,提示在神经组织稳态中的重要作用。通过与RNASET2共表达支持TMEM230对内膜系统的调节(溶酶体,线粒体,和囊泡)和STEAP家族成员(高尔基复合体)。胶质细胞成分的细胞内运输和细胞外分泌与内吞作用有关,运动蛋白介导的胞吐和吞噬作用。贩运成分包括金属蛋白,金属蛋白酶,聚糖,和糖缀合物加工和消化酶,在吞噬体和囊泡中发挥作用,以调节正常的神经组织微环境,稳态,应激反应,以及神经组织损伤或变性后的修复。异常高持续水平TMEM230促进金属蛋白表达,运输和分泌有助于高肿瘤级别神经胶质瘤的肿瘤相关浸润和血管过度形成。中枢神经或外周系统损伤后,TMEM230超常调节的上调促进组织伤口愈合,通过激活神经胶质和巨噬细胞产生的微通道/微管(称为血管模仿)和血管发芽和分支来进行重塑和血运重建。我们的结果支持TMEM230可能充当神经胶质瘤和神经胶质增生中一大类金属蛋白的运输和区室化的运动蛋白的主要调节因子。
    Glial cells provide physical and chemical support and protection for neurons and for the extracellular compartments of neural tissue through secretion of soluble factors, insoluble scaffolds, and vesicles. Additionally, glial cells have regenerative capacity by remodeling their physical microenvironment and changing physiological properties of diverse cell types in their proximity. Various types of aberrant glial and macrophage cells are associated with human diseases, disorders, and malignancy. We previously demonstrated that transmembrane protein, TMEM230 has tissue revascularization and regenerating capacity by its ability to secrete pro-angiogenic factors and metalloproteinases, inducing endothelial cell sprouting and channel formation. In healthy normal neural tissue, TMEM230 is predominantly expressed in glial and marcophate cells, suggesting a prominent role in neural tissue homeostasis. TMEM230 regulation of the endomembrane system was supported by co-expression with RNASET2 (lysosome, mitochondria, and vesicles) and STEAP family members (Golgi complex). Intracellular trafficking and extracellular secretion of glial cellular components are associated with endocytosis, exocytosis and phagocytosis mediated by motor proteins. Trafficked components include metalloproteins, metalloproteinases, glycans, and glycoconjugate processing and digesting enzymes that function in phagosomes and vesicles to regulate normal neural tissue microenvironment, homeostasis, stress response, and repair following neural tissue injury or degeneration. Aberrantly high sustained levels TMEM230 promotes metalloprotein expression, trafficking and secretion which contribute to tumor associated infiltration and hypervascularization of high tumor grade gliomas. Following injury of the central nervous or peripheral systems, transcient regulated upregulation of TMEM230 promotes tissue wound healing, remodeling and revascularization by activating glial and macrophage generated microchannels/microtubules (referred to as vascular mimicry) and blood vessel sprouting and branching. Our results support that TMEM230 may act as a master regulator of motor protein mediated trafficking and compartmentalization of a large class of metalloproteins in gliomas and gliosis.
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  • 文章类型: Journal Article
    来自大肠杆菌的细胞色素bd-I属于原核bd型氧还原酶的超家族。它包含三个血红素,b558,b595和d,并将双氧对喹啉的氧化与质子动力的产生耦合。该酶表现出对各种应激源的抗性,被认为是下一代抗菌剂的靶蛋白。通过使用电子吸收和MCD光谱,这项工作表明,氰化物与分离的完全还原的细胞色素bd-I中的血红素d2结合。氰化物诱导的差异吸收光谱显示血红素d2α带附近的变化,最小值为633nm,最大值为600nm左右,以及Soret地区的W形响应。血红素d2+的氰化物络合物的表观解离常数(Kd)为0.052M。氰化物结合的动力学是单相的,表明酶中存在单个配体结合位点。始终如一,MCD数据显示氰化物结合血红素d2+但不结合b5582+或b5952+。这与已发表的结构数据一致,即酶的活性位点不是双血红素位点。观察到的结合率(kobs)随着氰化物浓度的增加而增加,给出二阶速率常数(kon)为0.1M-1s-1。
    Cytochrome bd-I from Escherichia coli belongs to the superfamily of prokaryotic bd-type oxygen reductases. It contains three hemes, b558, b595 and d, and couples oxidation of quinol by dioxygen with the generation of a proton-motive force. The enzyme exhibits resistance to various stressors and is considered as a target protein for next-generation antimicrobials. By using electronic absorption and MCD spectroscopy, this work shows that cyanide binds to heme d2+ in the isolated fully reduced cytochrome bd-I. Cyanide-induced difference absorption spectra display changes near the heme d2+ α-band, a minimum at 633 nm and a maximum around 600 nm, and a W-shaped response in the Soret region. Apparent dissociation constant (Kd) of the cyanide complex of heme d2+ is ∼0.052 M. Kinetics of cyanide binding is monophasic, indicating the presence of a single ligand binding site in the enzyme. Consistently, MCD data show that cyanide binds to heme d2+ but not to b5582+ or b5952+. This agrees with the published structural data that the enzyme\'s active site is not a di-heme site. The observed rate of binding (kobs) increases as the concentration of cyanide is increased, giving a second-order rate constant (kon) of ∼0.1 M-1 s-1.
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  • 文章类型: Journal Article
    线粒体是药物靶向和递送的重要细胞内细胞器,因为它们似乎可以产生能量并执行许多其他细胞任务。线粒体功能障碍和功能障碍导致许多疾病。已经采取了许多举措来检测,诊断,和图像线粒体异常,并将药物精确地运输和积累到线粒体,都是因为癌症病理生理学的特殊线粒体方面。除了负膜电位和矛盾的线粒体动力学,它们包括高温,高水平的活性氧,高水平的谷胱甘肽,和高温。神经退行性疾病代表了广泛的衰弱性疾病。它们与基于个体的生理或解剖学的某些神经元群的丢失有关。细胞中的线粒体通常被认为是ATP产生的权威。该系统的破坏与几个细胞生理问题有关。神经退行性疾病的发展与线粒体功能障碍有关,根据病理生理学研究。似乎有大量证据表明线粒体功能障碍和氧化应激与神经退行性疾病的发展有关。已经广泛观察到线粒体功能障碍引发自噬,在神经退行性疾病中起作用。此外,兴奋性毒性和线粒体功能障碍与神经退行性疾病的发展有关。神经退行性疾病的病理生理学与细胞凋亡和坏死增加有关。以及线粒体功能障碍。多种合成和天然治疗已显示出治疗由线粒体衰竭引起的神经退行性疾病的功效。神经退行性疾病可以用靶向线粒体的现有药物有效治疗,尽管他们的精确配方知之甚少。因此,在神经退行性疾病的治疗和诊断中,迫切需要专注于创造专门针对线粒体的药物递送方法。
    Mitochondria are an essential intracellular organelle for medication targeting and delivery since they seem to create energy and conduct many other cellular tasks, and mitochondrial dysfunctions and malfunctions lead to many illnesses. Many initiatives have been taken to detect, diagnose, and image mitochondrial abnormalities, and to transport and accumulate medicines precisely to mitochondria, all because of special mitochondrial aspects of the pathophysiology of cancer. In addition to the negative membrane potential and paradoxical mitochondrial dynamics, they include high temperatures, high levels of reactive oxygen species, high levels of glutathione, and high temperatures. Neurodegenerative diseases represent a broad spectrum of debilitating illnesses. They are linked to the loss of certain groups of neurons based on an individual\'s physiology or anatomy. The mitochondria in a cell are generally accepted as the authority with respect to ATP production. Disruption of this system is linked to several cellular physiological issues. The development of neurodegenerative disorders has been linked to mitochondrial malfunction, according to pathophysiological studies. There seems to be substantial evidence connecting mitochondrial dysfunction and oxidative stress to the development of neurodegenerative disorders. It has been extensively observed that mitochondrial malfunction triggers autophagy, which plays a role in neurodegenerative disorders. In addition, excitotoxicity and mitochondrial dysfunction have been linked to the development of neurodegenerative disorders. The pathophysiology of neurodegenerative illnesses has been linked to increased apoptosis and necrosis, as well as mitochondrial malfunction. A variety of synthetic and natural treatments have shown efficacy in treating neurodegenerative illnesses caused by mitochondrial failure. Neurodegenerative illnesses can be effectively treated with existing drugs that target mitochondria, although their precise formulations are poorly understood. Therefore, there is an immediate need to focus on creating drug delivery methods specifically targeted at mitochondria in the treatment and diagnosis of neurodegenerative disorders.
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  • 文章类型: Journal Article
    紫色硫细菌(PSB)能够通过氧化还原的硫化合物进行缺氧光合作用,并被认为是一系列缺氧环境中硫循环的关键驱动因素。在这项研究中,我们表明,使用黄铁矿作为电子和硫源,长春变色菌(一种PSB物种)能够自养生长。比较生长概况,底物表征,和转录组测序数据为细菌利用黄铁矿和自养生长的分子机制提供了有价值的见解。具体来说,黄铁矿支持的细胞培养物(\“py\”\')表现出强劲但缓慢的生长速度和与硫化钠修正的阳性对照不同的模式。在py中观察到编码各种c型和b型细胞色素的基因上调约200倍,“指出这些分子在清除和传递电子从黄铁矿到细胞质代谢中的高度相关性。相反,与LH和RC复杂成分相关的基因的广泛下调表明电子源可能直接控制细菌细胞的光合活性。在硫代谢方面,编码周质或膜结合蛋白的基因(例如,FccAB和SoxYZ)在很大程度上上调,而那些编码细胞质蛋白(例如,Dsr和Apr组)被广泛抑制。其他值得注意的差异表达基因与鞭毛/菌毛/菌毛(+)有关,金属流出(+),ferrienterochelin(-),和[NiFe]氢化酶(+)。生物反应的黄铁矿的表征表明存在聚合硫。这些结果,第一次,把PSB和过渡金属硫化物化学的相互作用放在聚光灯下,具有推进多个领域的潜力,包括金属和硫生物地球化学,细菌胞外电子转移,和人工光合作用。
    目的:固相基质的微生物利用构成了环境微生物学的关键领域,为微生物代谢过程和适应性提供有价值的见解。该领域的最新进展深刻加深了我们对与这些情景相关的微生物生理学的了解,并刺激了生物合成和能源生产方面的创新。此外,对微生物和固相基质之间相互作用的研究直接将微生物活动与周围的矿物学环境联系起来,从而增强我们对相关生物地球化学循环的理解。我们的研究表明,在这一领域向前迈出了重要的一步,第一次,使用不溶性黄铁矿(FeS2)作为电子和硫源的紫色硫细菌的自养生长。呈现的比较增长概况,底物表征,转录组测序数据揭示了电子供体类型之间的关系,光合反应中心活动,以及这些能够进行缺氧光合作用的生物体中潜在的细胞外电子转移。此外,我们的研究结果可能为早期地球生物地球化学演化提供新的见解,为理解塑造我们星球历史的环境条件和微生物过程提供了有价值的约束。
    Purple sulfur bacteria (PSB) are capable of anoxygenic photosynthesis via oxidizing reduced sulfur compounds and are considered key drivers of the sulfur cycle in a range of anoxic environments. In this study, we show that Allochromatium vinosum (a PSB species) is capable of autotrophic growth using pyrite as the electron and sulfur source. Comparative growth profile, substrate characterization, and transcriptomic sequencing data provided valuable insight into the molecular mechanisms underlying the bacterial utilization of pyrite and autotrophic growth. Specifically, the pyrite-supported cell cultures (\"py\"\') demonstrated robust but much slower growth rates and distinct patterns from their sodium sulfide-amended positive controls. Up to ~200-fold upregulation of genes encoding various c- and b-type cytochromes was observed in \"py,\" pointing to the high relevance of these molecules in scavenging and relaying electrons from pyrite to cytoplasmic metabolisms. Conversely, extensive downregulation of genes related to LH and RC complex components indicates that the electron source may have direct control over the bacterial cells\' photosynthetic activity. In terms of sulfur metabolism, genes encoding periplasmic or membrane-bound proteins (e.g., FccAB and SoxYZ) were largely upregulated, whereas those encoding cytoplasmic proteins (e.g., Dsr and Apr groups) are extensively suppressed. Other notable differentially expressed genes are related to flagella/fimbriae/pilin(+), metal efflux(+), ferrienterochelin(-), and [NiFe] hydrogenases(+). Characterization of the biologically reacted pyrite indicates the presence of polymeric sulfur. These results have, for the first time, put the interplay of PSB and transition metal sulfide chemistry under the spotlight, with the potential to advance multiple fields, including metal and sulfur biogeochemistry, bacterial extracellular electron transfer, and artificial photosynthesis.
    OBJECTIVE: Microbial utilization of solid-phase substrates constitutes a critical area of focus in environmental microbiology, offering valuable insights into microbial metabolic processes and adaptability. Recent advancements in this field have profoundly deepened our knowledge of microbial physiology pertinent to these scenarios and spurred innovations in biosynthesis and energy production. Furthermore, research into interactions between microbes and solid-phase substrates has directly linked microbial activities to the surrounding mineralogical environments, thereby enhancing our understanding of the relevant biogeochemical cycles. Our study represents a significant step forward in this field by demonstrating, for the first time, the autotrophic growth of purple sulfur bacteria using insoluble pyrite (FeS2) as both the electron and sulfur source. The presented comparative growth profiles, substrate characterizations, and transcriptomic sequencing data shed light on the relationships between electron donor types, photosynthetic reaction center activities, and potential extracellular electron transfer in these organisms capable of anoxygenic photosynthesis. Furthermore, the findings of our study may provide new insights into early-Earth biogeochemical evolutions, offering valuable constraints for understanding the environmental conditions and microbial processes that shaped our planet\'s history.
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  • 文章类型: Journal Article
    微生物是全球生物地球化学硫循环的关键参与者。其中,由于它们的电活动和进行细胞外电子转移的能力,有些引起了特别的关注。越来越多的研究强调了它们广泛的系统发育和代谢多样性,揭示了它们在生态过程中的关键作用。在这次审查中,我们深入研究了硫酸盐还原细菌和厌氧烷烃氧化古细菌之间的电子转移过程,促进互养群落内的生长。此外,我们回顾了多细胞丝状硫氧化细菌中的长距离电子转移和潜在的细胞外电子转移现象。这些细菌,具有广阔的应用前景和生态意义,在各种生态过程中起着举足轻重的作用。随后,我们讨论了菌毛/细胞色素对电子转移的重要作用,并提出了探索和研究电活性微生物的前沿方法。这篇综述提供了参与生物地球化学硫循环的电活性微生物的全面概述。通过研究它们的电子转移机制,以及潜在的生态和应用影响,我们提供了对微生物硫代谢的新见解,从而推进可持续生物电子材料和生物修复技术的开发应用。
    Microorganisms are key players in the global biogeochemical sulfur cycle. Among them, some have garnered particular attention due to their electrical activity and ability to perform extracellular electron transfer. A growing body of research has highlighted their extensive phylogenetic and metabolic diversity, revealing their crucial roles in ecological processes. In this review, we delve into the electron transfer process between sulfate-reducing bacteria and anaerobic alkane-oxidizing archaea, which facilitates growth within syntrophic communities. Furthermore, we review the phenomenon of long-distance electron transfer and potential extracellular electron transfer in multicellular filamentous sulfur-oxidizing bacteria. These bacteria, with their vast application prospects and ecological significance, play a pivotal role in various ecological processes. Subsequently, we discuss the important role of the pili/cytochrome for electron transfer and presented cutting-edge approaches for exploring and studying electroactive microorganisms. This review provides a comprehensive overview of electroactive microorganisms participating in the biogeochemical sulfur cycle. By examining their electron transfer mechanisms, and the potential ecological and applied implications, we offer novel insights into microbial sulfur metabolism, thereby advancing applications in the development of sustainable bioelectronics materials and bioremediation technologies.
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  • 文章类型: Journal Article
    最近的全基因组关联研究已经确定了线粒体胺肟减少成分1(mARC1)中的错义变体p.A165T,其与非酒精性脂肪性肝炎(NASH)的全因肝硬化保护和预后改善密切相关。这种保护作用的确切机制是未知的。预测用苏氨酸取代丙氨酸165会影响mARC1蛋白的稳定性,并对其功能产生有害影响。为了研究机制,我们在人肝癌HepG2细胞中产生了敲入突变体mARC1A165T和催化死亡突变体C273A(作为对照),能够表征蛋白质亚细胞分布,稳定性,和从其内源性基因座表达的mARC1突变蛋白的生化功能。与野生型(WT)mARC1相比,我们发现A165T突变体在其锚定在线粒体外膜的传统位置之外表现出明显的错误定位,并降低了蛋白质的稳定性,导致较低的基础水平。我们评估了泛素蛋白酶体系统在mARC1A165T降解中的参与,并观察到A165T变体的泛素化增加和降解更快。此外,我们已经表明,携带MTARC1p.A165T变体的HepG2细胞在体外对外源添加的胺肟底物表现出较低的N-还原活性。来自这些生化和功能测定的数据表明MTARC1p.A165T变体消除酶功能的机制,这可能有助于其在肝病中的保护作用。
    Recent genome-wide association studies have identified a missense variant p.A165T in mitochondrial amidoxime-reducing component 1 (mARC1) that is strongly associated with protection from all-cause cirrhosis and improved prognosis in nonalcoholic steatohepatitis. The precise mechanism of this protective effect is unknown. Substitution of alanine 165 with threonine is predicted to affect mARC1 protein stability and to have deleterious effects on its function. To investigate the mechanism, we have generated a knock-in mutant mARC1 A165T and a catalytically dead mutant C273A (as a control) in human hepatoma HepG2 cells, enabling characterization of protein subcellular distribution, stability, and biochemical functions of the mARC1 mutant protein expressed from its endogenous locus. Compared to WT mARC1, we found that the A165T mutant exhibits significant mislocalization outside of its traditional location anchored in the mitochondrial outer membrane and reduces protein stability, resulting in lower basal levels. We evaluated the involvement of the ubiquitin proteasome system in mARC1 A165T degradation and observed increased ubiquitination and faster degradation of the A165T variant. In addition, we have shown that HepG2 cells carrying the MTARC1 p.A165T variant exhibit lower N-reductive activity on exogenously added amidoxime substrates in vitro. The data from these biochemical and functional assays suggest a mechanism by which the MTARC1 p.A165T variant abrogates enzyme function which may contribute to its protective effect in liver disease.
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  • 文章类型: Journal Article
    原子转移自由基聚合(ATRP)是用于受控聚合物合成的公知技术。然而,ATRP通常使用有毒的重金属离子作为催化剂,并且对分子氧敏感,这使得它应该在严格缺氧的条件下进行。在环境和生物相容性条件下进行ATRP是主要挑战。在这项研究中,在生物相容性条件下,细胞色素C被用作ATRP的有效生物催化剂。细胞色素C催化的ATRP显示1.19的相对低的聚合物分散指数。更有趣的是,细胞色素C催化的ATRP表现出优异的抗氧性,因为它可以在高溶解氧水平的有氧条件下进行。进一步的分析表明,嵌入细胞色素C中的Fe(II)可能充当催化中心,甲基自由基负责ATRP催化。这项工作探索了用于有氧ATRP的新型生物相容性催化剂,这可能为细胞色素C蛋白的实际应用和应用开辟新的维度。
    Atom-transfer radical polymerization (ATRP) is a well-known technique for controlled polymer synthesis. However, the ATRP usually employed toxic heavy metal ionas as the catalyst and was susceptible to molecular oxygen, which made it should be conducted under strictly anoxic condition. Conducting ATRP under ambient and biocompatible conditions is the major challenge. In this study, cytochrome C was explored as an efficient biocatalyst for ATRP under biocompatible conditions. The cytochrome C catalyzed ATRP showed a relatively low polymer dispersity index of 1.19. More interestingly, the cytochrome C catalyzed ATRP showed superior oxygen resistance as it could be performed under aerobic conditions with high dissolved oxygen level. Further analysis suggested that the Fe(II) embed in the cytochrome C might serve as the catalytic center and methyl radical was responsible for the ATRP catalysis. This work explored new biocompatible catalyst for aerobic ATRP, which might open new dimension for practical ATRP and application of cytochrome C protein.
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  • 文章类型: Journal Article
    通过将呼吸电子通过长达20年之久的争议身份的细丝释放到矿物质和其他微生物,从而还原了地球的生物地球化学。低温电子显微镜显示了氧化还原活性细胞色素的细丝,但是相同的细丝在细胞色素变性/抑制条件下表现出有机金属样导电性的标志。本文合成了对多血红素蛋白的基于结构的先前计算和动力学分析,以提出至少约7个细胞色素纳米线可以携带Geobacter细胞的呼吸通量,已知表达更多(≥20)细丝以增加生产性接触的可能性。相比之下,由于实验伪影和样品杂质,先前的电学和光谱结构表征被认为与已知的细胞色素丝在生理上无关或在物理上不合理。这种观点澄清了我们对生理金属-微生物相互作用的机械理解,并推进了合成生物学努力,以优化生物修复和能源或化学生产的相互作用。
    Geobacter sulfurreducens profoundly shapes Earth\'s biogeochemistry by discharging respiratory electrons to minerals and other microbes through filaments of a two-decades-long debated identity. Cryogenic electron microscopy has revealed filaments of redox-active cytochromes, but the same filaments have exhibited hallmarks of organic metal-like conductivity under cytochrome denaturing/inhibiting conditions. Prior structure-based calculations and kinetic analyses on multi-heme proteins are synthesized herein to propose that a minimum of ~7 cytochrome \'nanowires\' can carry the respiratory flux of a Geobacter cell, which is known to express somewhat more (≥20) filaments to increase the likelihood of productive contacts. By contrast, prior electrical and spectroscopic structural characterizations are argued to be physiologically irrelevant or physically implausible for the known cytochrome filaments because of experimental artifacts and sample impurities. This perspective clarifies our mechanistic understanding of physiological metal-microbe interactions and advances synthetic biology efforts to optimize those interactions for bioremediation and energy or chemical production.
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  • 文章类型: Journal Article
    近年来发现无标记的潜在药物分子azamulin是CYP3A4和CYP3A5的特异性抑制剂,但该分子也显示出与两种CYP3A亚型不同的结合能力和亲和力。为了探索微观机理,采用常规分子动力学(MD)模拟方法研究了两种同工型与氮丙素之间的动态相互作用。模拟结果表明,配体的结合导致两种CYP3A蛋白的结构性质不同。首先,与apo-CYP3A4相比,配体azamulin的结合可以导致CYP3A4结构柔性的变化,即holo-CYP3A4比apo-CYP3A4更灵活。CYP3A5的构造变更正好相反。配体结合增加CYP3A5的刚性。此外,详细分析了MD模拟中生产阶段的代表性结构,以获得配体氮丙素和两种CYP3A同工型在原子水平上的微观相互作用。推测活性位点组成和相互作用的差异是两种蛋白质结构性质变化的根本原因。由RamaswamyH.Sarma沟通。
    The unmarked potential drug molecule azamulin has been found to be a specific inhibitor of CYP3A4 and CYP3A5 in recent years, but this molecule also shows different binding ability and affinity to the two CYP3A isoforms. In order to explore the microscopic mechanism, conventional molecular dynamics (MD) simulation methods were performed to study the dynamic interactions between two isoforms and azamulin. The simulation results show that the binding of the ligand leads to different structural properties of two CYP3A proteins. First of all, compared with apo-CYP3A4, the binding of the ligand azamulin can lead to changes in the structural flexibility of CYP3A4, i.e., holo-CYP3A4 is more flexible than apo-CYP3A4. The structural changes of CYP3A5 are just the opposite. The ligand binding increases the rigidity of CYP3A5. Furthermore, the representative structures of the production phase in the MD simulation were in details analyzed to obtain the microscopic interactions between the ligand azamulin and two CYP3A isoforms at the atomic level. It is speculated that the difference of composition and interaction of the active sites is the fundamental cause of the change of structural properties of the two proteins.Communicated by Ramaswamy H. Sarma.
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