metalloproteins

金属蛋白
  • 文章类型: Journal Article
    金属离子与人类病原体的化学反应对它们的生存至关重要,能源生产,氧化还原信号,和利基优势。为了调节和操纵金属离子,病原菌中存在各种酶和金属螯合剂。金属酶包含过渡金属如铁,锌,钴,和铜在他们的反应中心执行必要的代谢功能;然而,铁和铜变得越来越重要。Multicopper氧化酶具有在铜离子的帮助下在酚类底物上进行氧化还原反应的能力。据报道,它们来自肠杆菌科,即肠沙门氏菌,大肠杆菌,和小肠结肠炎耶尔森氏菌,但是它们在毒力中的作用仍然知之甚少。同样,超氧化物歧化酶参与减少氧化应激并允许病原体存活。它们在毒力和存活中的作用在鼠伤寒沙门氏菌和结核分枝杆菌中已经确立。Further,为了确保在压力下生存,比如金属饥饿或金属毒性,病原体的氧化还原金属酶和金属运输系统积极参与金属稳态。最近,组学研究帮助提出了新的目标,以调节致病性菌株的定植潜力。目前的综述集中在氧化还原金属酶的主要作用,特别是人类致病菌的MCO和SODs。
    The chemistry of metal ions with human pathogens is essential for their survival, energy generation, redox signaling, and niche dominance. To regulate and manipulate the metal ions, various enzymes and metal chelators are present in pathogenic bacteria. Metalloenzymes incorporate transition metal such as iron, zinc, cobalt, and copper in their reaction centers to perform essential metabolic functions; however, iron and copper have gained more importance. Multicopper oxidases have the ability to perform redox reaction on phenolic substrates with the help of copper ions. They have been reported from Enterobacteriaceae, namely Salmonella enterica, Escherichia coli, and Yersinia enterocolitica, but their role in virulence is still poorly understood. Similarly, superoxide dismutases participate in reducing oxidative stress and allow the survival of pathogens. Their role in virulence and survival is well established in Salmonella typhimurium and Mycobacterium tuberculosis. Further, to ensure survival against stress, like metal starvation or metal toxicity, redox metalloenzymes and metal transportation systems of pathogens actively participate in metal homeostasis. Recently, the omics and protein structure biology studies have helped to predict new targets for regulation the colonization potential of the pathogenic strains. The current review is focused on the major roles of redox metalloenzymes, especially MCOs and SODs of human pathogenic bacteria.
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  • 文章类型: Journal Article
    电感耦合等离子体质谱及其同位素富集标准品制备方法的进展,允许通过同位素稀释质谱法高精度测量金属蛋白。这种技术现在已经达到了成熟的水平,即精度的阶跃变化,精度,和可追溯性,特别是,临床,生物医学测量是可以实现的。目前的临床测量,这需要在复杂样品基质存在下的低检测限,使用基于免疫化学的间接方法研究人类疾病。然而,这种方法的可追溯性差,要求在提供基于矩阵的参考材料的基础上进行比较,用作分析标准。这导致当需要改变参考材料时的困难,通常导致临床结果和参考范围缺乏实验室间和时间可比性。在这次审查中,我们专注于临床研究中最重要的金属蛋白,为了说明色谱与无机质谱联用的属性如何用于直接测量金属蛋白如血红蛋白,转铁蛋白,和铜蓝蛋白.通过使用这种方法,我们希望展示同位素稀释分析如何作为参考方法,以提高可追溯性和支持临床,生物医学,和其他生物测量。
    Advances in inductively coupled plasma mass spectrometry and the methods used to prepare isotopically enriched standards, allow for the high accuracy measurement of metalloproteins by isotope dilution mass spectrometry. This technique has now reached a level of maturity whereby a step change in the accuracy, precision, and traceability of, in particular, clinical, and biomedical measurements is achievable. Current clinical measurements, which require low limits of detection in the presence of complex sample matrices, use indirect methods based on immunochemistry for the study of human disease. However, this approach suffers from poor traceability, requiring comparisons based on provision of matrix-based reference materials, used as analytical standards. This leads to difficulty when changes in the reference material are required, often resulting in a lack of interlaboratory and temporal comparability in clinical results and reference ranges. In this review, we focus on the most important metalloproteins for clinical studies, to illustrate how the attributes of chromatography coupled to inorganic mass spectrometry can be used for the direct measurement of metalloproteins such as hemoglobin, transferrin, and ceruloplasmin. By using this approach, we hope to demonstrate how isotope dilution analysis can be used as a reference method to improve traceability and underpin clinical, biomedical, and other biological measurements.
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  • 文章类型: Journal Article
    1976年引入了多尺度量子力学/分子力学(QM/MM)方法,而这种方法的广泛接受始于1990年代。QM/MM方法与分子动力学(MD)模拟相结合,也称为QM/MM/MD方法,是研究复杂分子系统化学反应机理的强大而有前途的工具,药物输送,分子器件的特性,有机电子,等。在本次审查中,多尺度方法中的主要方法,即,密度泛函理论(DFT),半经验方法论(SE),MD模拟,MM,并简要讨论了他们的新进展。然后,对金属蛋白的计算和反应进行了综述,其中特别注意固氮酶,该固氮酶通过称为固氮和FeMo辅因子的过程催化大气氮分子N2转化为NH3。
    The multiscaling quantum mechanics/molecular mechanics (QM/MM) approach was introduced in 1976, while the extensive acceptance of this methodology started in the 1990s. The combination of QM/MM approach with molecular dynamics (MD) simulation, otherwise known as the QM/MM/MD approach, is a powerful and promising tool for the investigation of chemical reactions\' mechanism of complex molecular systems, drug delivery, properties of molecular devices, organic electronics, etc. In the present review, the main methodologies in the multiscaling approaches, i.e., density functional theory (DFT), semiempirical methodologies (SE), MD simulations, MM, and their new advances are discussed in short. Then, a review on calculations and reactions on metalloproteins is presented, where particular attention is given to nitrogenase that catalyzes the conversion of atmospheric nitrogen molecules N₂ into NH₃ through the process known as nitrogen fixation and the FeMo-cofactor.
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  • 文章类型: Journal Article
    在自闭症谱系障碍(ASD)中,有多种证据表明硫氨基酸(SAA)代谢受损。例如,蛋氨酸的浓度,与健康个体相比,患有ASD的个体的体液中的半胱氨酸和S-腺苷甲硫氨酸(SAM)显著较低,而S-腺苷高半胱氨酸(SAH)的浓度显著较高。减少的甲硫氨酸和SAM可能反映了受损的再甲基化途径,而增加的SAH可能反映了分解代谢方向的S-腺苷高半胱氨酸水解酶活性降低。降低的SAM/SAH比率反映了受损的甲基化能力。我们假设多种机制来解释氧化应激的相互作用,神经炎症,汞暴露,母亲使用丙戊酸盐,改变的肠道微生物组和某些遗传变异可能导致这些SAA代谢型。此外,我们还提出了一些机制来解释SAA代谢异常的代谢后果。例如在大脑中,降低SAM/SAH比率将导致褪黑激素缺乏和许多生物分子如DNA的低甲基化,RNA和组蛋白。除了先前提出的机制之外,我们认为,“自由基SAM”酶的活性受损将导致内源性硫辛酸合成减少,钼辅因子合成减少和卟啉代谢受损导致线粒体功能障碍,卟啉尿症和硫酸化能力受损。此外,SAM的消耗也可能导致ASD亚组中mTOR信号通路的紊乱。提出的“SAM耗竭假说”是一个包容性模型,用于解释在ASD儿童子集中观察到的异质性风险因素与代谢型之间的关系。
    There are multiple lines of evidence for an impaired sulfur amino acid (SAA) metabolism in autism spectrum disorder (ASD). For instance, the concentrations of methionine, cysteine and S-adenosylmethionine (SAM) in body fluids of individuals with ASD is significantly lower while the concentration of S-adenosylhomocysteine (SAH) is significantly higher as compared to healthy individuals. Reduced methionine and SAM may reflect impaired remethylation pathway whereas increased SAH may reflect reduced S-adenosylhomocysteine hydrolase activity in the catabolic direction. Reduced SAM/SAH ratio reflects an impaired methylation capacity. We hypothesize multiple mechanisms to explain how the interplay of oxidative stress, neuroinflammation, mercury exposure, maternal use of valproate, altered gut microbiome and certain genetic variants may lead to these SAA metabotypes. Furthermore, we also propose a number of mechanisms to explain the metabolic consequences of abnormal SAA metabotypes. For instance in the brain, reduced SAM/SAH ratio will result in melatonin deficiency and hypomethylation of a number of biomolecules such as DNA, RNA and histones. In addition to previously proposed mechanisms, we propose that impaired activity of \"radical SAM\" enzymes will result in reduced endogenous lipoic acid synthesis, reduced molybdenum cofactor synthesis and impaired porphyrin metabolism leading to mitochondrial dysfunction, porphyrinuria and impaired sulfation capacity. Furthermore depletion of SAM may also lead to the disturbed mTOR signaling pathway in a subgroup of ASD. The proposed \"SAM-depletion hypothesis\" is an inclusive model to explain the relationship between heterogeneous risk factors and metabotypes observed in a subset of children with ASD.
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  • 文章类型: Journal Article
    金属在生物系统中起着至关重要的作用,并且在许多蛋白质中需要作为结构或催化辅因子。破坏金属的稳态控制和/或空间分布可导致疾病。已经开发了成像技术来可视化生物样品中的元素分布。通过成像质谱和成像X射线荧光测量元素分布越来越多地与可以评估组织学特征和分子组成的技术一起使用。来自几种模态的数据可以作为多模态图像进行查询,以关联形态学,元素,和分子特性。元素和分子分布也已轴向解析,以实现三维体积,大大增加了生物信息。在这次审查中,我们概述了金属成像领域的最新发展,重点是二维和三维的多模态研究。我们特别强调了关于金属稳态如何影响人类健康的技术进步和生物学应用的研究。
    Metals play an essential role in biological systems and are required as structural or catalytic co-factors in many proteins. Disruption of the homeostatic control and/or spatial distributions of metals can lead to disease. Imaging technologies have been developed to visualize elemental distributions across a biological sample. Measurement of elemental distributions by imaging mass spectrometry and imaging X-ray fluorescence are increasingly employed with technologies that can assess histological features and molecular compositions. Data from several modalities can be interrogated as multimodal images to correlate morphological, elemental, and molecular properties. Elemental and molecular distributions have also been axially resolved to achieve three-dimensional volumes, dramatically increasing the biological information. In this review, we provide an overview of recent developments in the field of metal imaging with an emphasis on multimodal studies in two and three dimensions. We specifically highlight studies that present technological advancements and biological applications of how metal homeostasis affects human health.
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  • 文章类型: Journal Article
    Objective: Oral supplementation with iron is a standard intervention for treating or preventing iron deficiency with or without anemia. Over the last few decades, various forms of oral iron have been developed to improve treatment tolerability and iron bioavailability. In this review, we gathered research data regarding the use of iron protein succinylate since it was first marketed in the 1980s.Methods: Electronic databases - PubMed and the Cochrane Library - were searched for studies published up to March 2019. Clinical or observational studies reporting data on the tolerability of oral iron protein succinylate were included. Results were statistically described to evaluate and compare the efficacy and safety of iron protein succinylate with the comparators under study.Results: Iron protein succinylate was investigated in 54 studies: 38 randomized clinical trials and 16 observational studies, with a total of 8454 subjects. Of them, 8142 were included in the efficacy analysis: patients were divided into three population subtypes: general (n = 1899), gynecological/obstetric (n = 5283), and pediatric (n = 960). In total, 6450 patients received iron protein succinylate, experiencing a significant change in hemoglobin and ferritin in all populations. The change in all parameters was similar or higher with iron protein succinylate compared to other iron treatments evaluated. Overall, study groups receiving iron protein succinylate reported the lowest rate of adverse events.Conclusions: Although all iron treatments analyzed are effective and safe, our results suggest that iron protein succinylate may be an excellent choice to treat iron deficiency and anemia due to its superior effectiveness and tolerability.
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  • 文章类型: Journal Article
    BACKGROUND: The family of tripartite motif (TRIM) proteins, which includes 80 known TRIM protein genes in humans, play a key role in cellular processes. TRIM59, a member of the TRIM family of proteins, has been reported to be involved in the carcinogenesis of multiple types of tumors. However, the prognostic value of TRIM59 in the survival of tumor patients remains controversial. We therefore conducted a meta-analysis to assess the prognostic significance of TRIM59 in cancer patients.
    METHODS: PubMed, Embase, VIP, CNKI and Wanfang Data were searched for eligible reports published before September 30, 2018. The hazard ratio (HR) and 95% confidence intervals (CIs) were adopted to estimate the association between TRIM59 and overall survival (OS).
    RESULTS: Six studies with 1584 patients were included to assess the effect. The results showed that high levels of TRIM59 were significantly associated with poor OS in cancer patients (HR = 1.43, 95%CI: 1.24-1.66, P < .001), indicating that higher TRIM59 expression could be an independent prognostic factor for poor survival in cancer patients.
    CONCLUSIONS: Our meta-analysis suggests that higher TRIM59 expression predicts poor prognosis in cancer patients, and it may therefore serve as a promising prognostic factor.
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  • 文章类型: Case Reports
    Molybdenum cofactor deficiency (MoCD) is a rare autosomal-recessive disorder that results in the combined deficiency of molybdenum-dependent enzymes. Four different genes are involved in Molybdenum cofactor biosynthesis: MOCS1, MOCS2, MOCS3, and GEPH. The classical form manifests in the neonatal period with severe encephalopathy, including intractable seizures, MRI changes that resemble hypoxic-ischemic injury, microcephaly, and early death. To date, an atypical phenotype with late-onset has been reported in the literature in 13 patients.
    We describe a late-onset and a relatively mild phenotype in a patient with MOCS2 homozygous mutation.
    Pyramidal and extrapyramidal signs are recognized in those patients, often exacerbated by intercurrent illness. Expressive language is usually compromised. Neurological deterioration is possible even in adulthood, probably due to accumulation of sulfite with time.
    Sulfite inhibition of mitochondrial metabolism could be responsible for the ischemic lesions described in patients with MoCD or alternatively could predispose the brain to suffer an ischemic damage through the action of other insults, for instance intercurrent illness. It is possible that sulfite accumulation together with other external triggers, can lead to neurological deterioration even in adulthood. The role of other factors involved in clinical expression should be investigated to establish the reason for phenotypic variability in patients with the same mutation.
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    文章类型: Journal Article
    Metallo-beta-lactamase (MBL)-producing Pseudomonas aeruginosa is considered to be a serious threat to human health worldwide. Limited information is available concerning the prevalence of MBL-producing P. aeruginosa in Iran. The aim of the present study was to investigate the prevalence of MBL-producing P. aeruginosa in different parts of Iran. We searched major electronic databases including PubMed, ISI Web of Science, Scopus and Google Scholar as well as two Iranian search engines using appropriate keywords. After applying inclusion and exclusion criteria, related papers were recruited for the study. The prevalence of MBL-producing P. aeruginosa in Iranian population was about 32.4 %. Our findings also revealed that the highest prevalence of MBL-producing P. aeruginosa was in Isfahan with 60% (95% CI: 0.27-0.86). In addition, in Iranian population the most reported MBL gene was blaVIM and blaIMP, with frequencies of 19% (95% CI: 0.15-0.23) and 11% (95% CI: 0.08-0.14), respectively. Based on our findings, in the majority of Iranian hospitals, the prevalence of MBL-producing P. aeruginosa is alarmingly high necessitating the need for designing appropriate infection control programs.
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  • 文章类型: Journal Article
    脲酶是将尿素水解成氨和二氧化碳的金属酶。它们是最早结晶的酶,和他们在一起,酶是蛋白质的概念被接受了。在过去的三十年中,人们发现了与脲酶活性无关的脲酶的新毒性。自从我们首次描述卡纳毒素的神经毒性以来,杰克豆脲酶的同工型,1981年出现在Toxicon中,已经发表了大约一百篇关于植物和微生物脲酶的“新”特性的文章。在这里,我们回顾了有关脲酶非酶特性的现有知识。植物脲酶和微生物脲酶通过涉及真菌膜透化的机制对丝状真菌和酵母具有真菌毒性。植物和至少一些细菌脲酶具有有效的杀虫作用。这种昆虫毒性部分依赖于昆虫消化酶对摄入的脲酶进行蛋白水解后释放的内部肽。完整的蛋白质及其衍生肽对昆虫具有神经毒性,并影响许多其他生理功能。比如利尿,肌肉收缩和免疫力。在哺乳动物模型中,一些尿素酶在注射时具有急性神经毒性,至少部分是由酶非依赖性效应。长期以来,细菌脲酶已被认为是产生脲酶的微生物引起疾病的重要毒力因子。脲酶激活不同哺乳动物细胞中的胞吐作用,募集类二十烷酸和Ca(2+)依赖性途径,即使它们的尿素降解活性被不可逆的抑制剂阻断。脲酶是中性粒细胞(和一些细菌)识别的趋化因子,激活它们和血小板进入促炎状态。尿素酶的分泌诱导可能在人类和其他动物的真菌和细菌疾病中起作用。现在公认的这些蛋白质的“月光”特性使人们对脲酶重新产生了兴趣,因为它们具有生物技术潜力,可以改善植物对害虫的防御能力,并可以作为改善由致病性脲酶产生的微生物引起的疾病的潜在目标。
    Ureases are metalloenzymes that hydrolyze urea into ammonia and carbon dioxide. They were the first enzymes to be crystallized and, with them, the notion that enzymes are proteins became accepted. Novel toxic properties of ureases that are independent of their enzyme activity have been discovered in the last three decades. Since our first description of the neurotoxic properties of canatoxin, an isoform of the jack bean urease, which appeared in Toxicon in 1981, about one hundred articles have been published on \"new\" properties of plant and microbial ureases. Here we review the present knowledge on the non-enzymatic properties of ureases. Plant ureases and microbial ureases are fungitoxic to filamentous fungi and yeasts by a mechanism involving fungal membrane permeabilization. Plant and at least some bacterial ureases have potent insecticidal effects. This entomotoxicity relies partly on an internal peptide released upon proteolysis of ingested urease by insect digestive enzymes. The intact protein and its derived peptide(s) are neurotoxic to insects and affect a number of other physiological functions, such as diuresis, muscle contraction and immunity. In mammal models some ureases are acutely neurotoxic upon injection, at least partially by enzyme-independent effects. For a long time bacterial ureases have been recognized as important virulence factors of diseases by urease-producing microorganisms. Ureases activate exocytosis in different mammalian cells recruiting eicosanoids and Ca(2+)-dependent pathways, even when their ureolytic activity is blocked by an irreversible inhibitor. Ureases are chemotactic factors recognized by neutrophils (and some bacteria), activating them and also platelets into a pro-inflammatory \"status\". Secretion-induction by ureases may play a role in fungal and bacterial diseases in humans and other animals. The now recognized \"moonlighting\" properties of these proteins have renewed interest in ureases for their biotechnological potential to improve plant defense against pests and as potential targets to ameliorate diseases due to pathogenic urease-producing microorganisms.
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