Pub Date : 2022-04-19DOI: 10.1038/s41467-022-29757-9
Mihael S Grbić, Eoin C T O'Farrell, Yosuke Matsumoto, Kentaro Kuga, Manuel Brando, Robert Küchler, Andriy H Nevidomskyy, Makoto Yoshida, Toshiro Sakakibara, Yohei Kono, Yasuyuki Shimura, Michael L Sutherland, Masashi Takigawa, Satoru Nakatsuji
Intermetallic compounds containing f-electron elements have been prototypical materials for investigating strong electron correlations and quantum criticality (QC). Their heavy fermion ground state evoked by the magnetic f-electrons is susceptible to the onset of quantum phases, such as magnetism or superconductivity, due to the enhanced effective mass (m*) and a corresponding decrease of the Fermi temperature. However, the presence of f-electron valence fluctuations to a non-magnetic state is regarded an anathema to QC, as it usually generates a paramagnetic Fermi-liquid state with quasiparticles of moderate m*. Such systems are typically isotropic, with a characteristic energy scale T0 of the order of hundreds of kelvins that require large magnetic fields or pressures to promote a valence or magnetic instability. Here we show the discovery of a quantum critical behaviour and a Lifshitz transition under low magnetic field in an intermediate valence compound α-YbAlB4. The QC origin is attributed to the anisotropic hybridization between the conduction and localized f-electrons. These findings suggest a new route to bypass the large valence energy scale in developing the QC.
含有 f 电子元素的金属间化合物一直是研究强电子关联和量子临界（QC）的典型材料。由于有效质量（m*）的增强和费米温度的相应降低，磁性 f 电子唤起的重费米子基态容易导致磁性或超导性等量子相的出现。然而，非磁态 f 电子价态波动的存在被认为是量子相位的天敌，因为它通常会产生具有中等 m* 准粒子的顺磁费米液体态。这种系统通常是各向同性的，其特征能级 T0 为数百开尔文，需要大磁场或压力来促进价态或磁态不稳定性。在这里，我们发现了中间价化合物 α-YbAlB4 在低磁场下的量子临界行为和 Lifshitz 转变。量子临界源于传导电子和局部 f 电子之间的各向异性杂化。这些发现为发展 QC 提出了一条绕过大价态能级的新途径。
{"title":"Anisotropy-driven quantum criticality in an intermediate valence system.","authors":"Mihael S Grbić, Eoin C T O'Farrell, Yosuke Matsumoto, Kentaro Kuga, Manuel Brando, Robert Küchler, Andriy H Nevidomskyy, Makoto Yoshida, Toshiro Sakakibara, Yohei Kono, Yasuyuki Shimura, Michael L Sutherland, Masashi Takigawa, Satoru Nakatsuji","doi":"10.1038/s41467-022-29757-9","DOIUrl":"10.1038/s41467-022-29757-9","url":null,"abstract":"<p><p>Intermetallic compounds containing f-electron elements have been prototypical materials for investigating strong electron correlations and quantum criticality (QC). Their heavy fermion ground state evoked by the magnetic f-electrons is susceptible to the onset of quantum phases, such as magnetism or superconductivity, due to the enhanced effective mass (m<sup>*</sup>) and a corresponding decrease of the Fermi temperature. However, the presence of f-electron valence fluctuations to a non-magnetic state is regarded an anathema to QC, as it usually generates a paramagnetic Fermi-liquid state with quasiparticles of moderate m<sup>*</sup>. Such systems are typically isotropic, with a characteristic energy scale T<sub>0</sub> of the order of hundreds of kelvins that require large magnetic fields or pressures to promote a valence or magnetic instability. Here we show the discovery of a quantum critical behaviour and a Lifshitz transition under low magnetic field in an intermediate valence compound α-YbAlB<sub>4</sub>. The QC origin is attributed to the anisotropic hybridization between the conduction and localized f-electrons. These findings suggest a new route to bypass the large valence energy scale in developing the QC.</p>","PeriodicalId":50454,"journal":{"name":"FEBS Letters","volume":"9 1","pages":"2141"},"PeriodicalIF":14.7,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9019086/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74609216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this Scientists' Forum article, we present a new app, GENIGMA, launched by structural genomics specialist Marc A. Marti‐Renom and his team, aimed at mapping the 3D genome of cancer cell lines. GENIGMA is a digital game, which was designed and tested through a co‐creation process with citizens. Finally, by playing the game, citizens produce data, reaching beyond the capacity of artificial intelligence. This is an exceptional experiment of extreme citizen science, which broadens the implications of open science.
在这篇科学家论坛的文章中，我们介绍了一个新的应用程序，GENIGMA，由结构基因组学专家Marc a . Marti‐renm和他的团队推出，旨在绘制癌细胞系的3D基因组。GENIGMA是一款数字游戏，通过与市民共同创造的过程进行设计和测试。最后，通过玩游戏，公民产生数据，这超出了人工智能的能力。这是一个极端公民科学的特殊实验，它扩大了开放科学的含义。
{"title":"GENIGMA: an app to map the 3D genome of cancer cell lines through extreme citizen science","authors":"D. Ruffell","doi":"10.1002/1873-3468.14331","DOIUrl":"https://doi.org/10.1002/1873-3468.14331","url":null,"abstract":"In this Scientists' Forum article, we present a new app, GENIGMA, launched by structural genomics specialist Marc A. Marti‐Renom and his team, aimed at mapping the 3D genome of cancer cell lines. GENIGMA is a digital game, which was designed and tested through a co‐creation process with citizens. Finally, by playing the game, citizens produce data, reaching beyond the capacity of artificial intelligence. This is an exceptional experiment of extreme citizen science, which broadens the implications of open science.","PeriodicalId":50454,"journal":{"name":"FEBS Letters","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44749506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carotenoids with rare 6‐hydroxy‐3‐keto‐ε‐end groups, such as piprixanthin, vitixanthin, or cochloxanthin, found in manakin birds or plants, are rare carotenoids with high antioxidant activity. The same chemical structure is found in abscisic acid or blumenol, apocarotenoids found in plants or fungi. In this study, we serendipitously discovered that the promiscuous activity of the β‐carotene hydroxylase CrtZ, a diiron‐containing membrane protein, can catalyze the formation of 6‐hydroxy‐3‐keto‐ε‐end by using epoxycarotenoids antheraxanthin or violaxanthin as substrate. We suggest that the reaction mechanism is similar to that of a rhodoxanthin biosynthetic enzyme. Our results provide a further understanding of the reaction mechanism of diiron‐containing β‐carotene hydroxylases, as well as insight into the biosynthesis of natural compounds with 6‐hydroxy‐3‐keto‐ε‐end carotenoid derivatives.
{"title":"Promiscuous activity of β‐carotene hydroxylase CrtZ on epoxycarotenoids leads to the formation of rare carotenoids with 6‐hydroxy‐3‐keto‐ε‐ends","authors":"Maiko Furubayashi, T. Maoka, Y. Mitani","doi":"10.1002/1873-3468.14342","DOIUrl":"https://doi.org/10.1002/1873-3468.14342","url":null,"abstract":"Carotenoids with rare 6‐hydroxy‐3‐keto‐ε‐end groups, such as piprixanthin, vitixanthin, or cochloxanthin, found in manakin birds or plants, are rare carotenoids with high antioxidant activity. The same chemical structure is found in abscisic acid or blumenol, apocarotenoids found in plants or fungi. In this study, we serendipitously discovered that the promiscuous activity of the β‐carotene hydroxylase CrtZ, a diiron‐containing membrane protein, can catalyze the formation of 6‐hydroxy‐3‐keto‐ε‐end by using epoxycarotenoids antheraxanthin or violaxanthin as substrate. We suggest that the reaction mechanism is similar to that of a rhodoxanthin biosynthetic enzyme. Our results provide a further understanding of the reaction mechanism of diiron‐containing β‐carotene hydroxylases, as well as insight into the biosynthesis of natural compounds with 6‐hydroxy‐3‐keto‐ε‐end carotenoid derivatives.","PeriodicalId":50454,"journal":{"name":"FEBS Letters","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45512275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Mohr, M. Crawford, P. Jasbi, S. Fessler, K. Sweazea
Systemic inflammation is associated with chronic disease and is purported to be a main pathogenic mechanism underlying metabolic conditions. Microbes harbored in the host gastrointestinal tract release signaling byproducts from their cell wall, such as lipopolysaccharides (LPS), which can act locally and, after crossing the gut barrier and entering circulation, also systemically. Defined as metabolic endotoxemia, elevated concentrations of LPS in circulation are associated with metabolic conditions and chronic disease. As such, measurement of LPS is highly prevalent in animal and human research investigating these states. Indeed, LPS can be a potent stimulant of host immunity, but this response depends on the microbial species’ origin, a parameter often overlooked in both preclinical and clinical investigations. Indeed, the lipid A portion of LPS is mutable and comprises the main virulence and endotoxic component, thus contributing to the structural and functional diversity among LPSs from microbial species. In this review, we discuss how such structural differences in LPS can induce differential immunological responses in the host.
{"title":"Lipopolysaccharide and the gut microbiota: considering structural variation","authors":"A. Mohr, M. Crawford, P. Jasbi, S. Fessler, K. Sweazea","doi":"10.1002/1873-3468.14328","DOIUrl":"https://doi.org/10.1002/1873-3468.14328","url":null,"abstract":"Systemic inflammation is associated with chronic disease and is purported to be a main pathogenic mechanism underlying metabolic conditions. Microbes harbored in the host gastrointestinal tract release signaling byproducts from their cell wall, such as lipopolysaccharides (LPS), which can act locally and, after crossing the gut barrier and entering circulation, also systemically. Defined as metabolic endotoxemia, elevated concentrations of LPS in circulation are associated with metabolic conditions and chronic disease. As such, measurement of LPS is highly prevalent in animal and human research investigating these states. Indeed, LPS can be a potent stimulant of host immunity, but this response depends on the microbial species’ origin, a parameter often overlooked in both preclinical and clinical investigations. Indeed, the lipid A portion of LPS is mutable and comprises the main virulence and endotoxic component, thus contributing to the structural and functional diversity among LPSs from microbial species. In this review, we discuss how such structural differences in LPS can induce differential immunological responses in the host.","PeriodicalId":50454,"journal":{"name":"FEBS Letters","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2022-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45684737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flavohaemoglobins (FlavoHbs) function as nitric oxide dioxygenases, oxidizing nitric oxide with nitrite and shuttling electrons from NAD(P)H via FAD and O2. Here, using pulse radiolysis, we investigate intramolecular electron transfer between FAD and haem b in FlavoHbs. We found that reduction of FlavoHb with hydrated electrons proceeded via two phases: an initial fast phase and a second slower process. Absorbance measured at 600 nm revealed fast flavin reduction followed by a slower decrease corresponding to reoxidation of FAD. The slower process was partially lost in FlavoHbs lacking FAD. These results suggest that the slower phase is attributable to intramolecular electron transfer from FAD to the haem iron. The rate constant in the absence of azole compound (3.3 × 103 s‐1) was accelerated ~ 10‐fold (2.7 × 104 s‐1) by the binding of econazole, reflecting a conformational change in the open‐to‐closed transition.
{"title":"Interdomain electron transfer in flavohaemoglobin from Candida norvegensis with antibiotic azole compounds","authors":"Kazuo Kobayashi, J. Igarashi, T. Kozawa","doi":"10.1002/1873-3468.14327","DOIUrl":"https://doi.org/10.1002/1873-3468.14327","url":null,"abstract":"Flavohaemoglobins (FlavoHbs) function as nitric oxide dioxygenases, oxidizing nitric oxide with nitrite and shuttling electrons from NAD(P)H via FAD and O2. Here, using pulse radiolysis, we investigate intramolecular electron transfer between FAD and haem b in FlavoHbs. We found that reduction of FlavoHb with hydrated electrons proceeded via two phases: an initial fast phase and a second slower process. Absorbance measured at 600 nm revealed fast flavin reduction followed by a slower decrease corresponding to reoxidation of FAD. The slower process was partially lost in FlavoHbs lacking FAD. These results suggest that the slower phase is attributable to intramolecular electron transfer from FAD to the haem iron. The rate constant in the absence of azole compound (3.3 × 103 s‐1) was accelerated ~ 10‐fold (2.7 × 104 s‐1) by the binding of econazole, reflecting a conformational change in the open‐to‐closed transition.","PeriodicalId":50454,"journal":{"name":"FEBS Letters","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2022-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46127173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Retraction statement: Zhiyong Yan, Jianpeng Wang, Chao Wang, Yingbing Jiao, Weiguo Qi, Shusheng Che (2014), miR-96/HBP1/Wnt/β-catenin regulatory circuitry promotes glioma growth, FEBS Letters, 588: 3038-3046. https://doi.org/10.1016/j.febslet.2014.06.017 The above article from FEBS Letters, published online on 12 June 2014 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal's Editor-in-Chief, Michael Brunner, the FEBS Press and John Wiley & Sons Ltd. The retraction has been agreed due to concerns raised about Figures 4C, 6A and 6C. There is evidence of image manipulation and the duplication of image elements from four subsequently published articles. The authors and the authors' institution failed to reply to the journal's requests to provide original data confirming that the images arose from the reported experiments are genuine, unmodified and suitable for publication. Reference 1 Yan Z, Wang J, Wang C, Jiao Y, Qi W, Che S. miR-96/HBP1/Wnt/β-catenin regulatory circuitry promotes glioma growth. FEBS Lett. 2014;588:3038-46.
{"title":"Retraction statement: miR‐96/HBP1/Wnt/β‐catenin regulatory circuitry promotes glioma growth","authors":"M. Brunner","doi":"10.1002/1873-3468.14284","DOIUrl":"https://doi.org/10.1002/1873-3468.14284","url":null,"abstract":"Retraction statement: Zhiyong Yan, Jianpeng Wang, Chao Wang, Yingbing Jiao, Weiguo Qi, Shusheng Che (2014), miR-96/HBP1/Wnt/β-catenin regulatory circuitry promotes glioma growth, FEBS Letters, 588: 3038-3046. https://doi.org/10.1016/j.febslet.2014.06.017 The above article from FEBS Letters, published online on 12 June 2014 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal's Editor-in-Chief, Michael Brunner, the FEBS Press and John Wiley & Sons Ltd. The retraction has been agreed due to concerns raised about Figures 4C, 6A and 6C. There is evidence of image manipulation and the duplication of image elements from four subsequently published articles. The authors and the authors' institution failed to reply to the journal's requests to provide original data confirming that the images arose from the reported experiments are genuine, unmodified and suitable for publication. Reference 1 Yan Z, Wang J, Wang C, Jiao Y, Qi W, Che S. miR-96/HBP1/Wnt/β-catenin regulatory circuitry promotes glioma growth. FEBS Lett. 2014;588:3038-46.","PeriodicalId":50454,"journal":{"name":"FEBS Letters","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41496392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alberto Blanch Jover, Nicola de Franceschi, D. Fenel, W. Weissenhorn, C. Dekker
The Cdv proteins constitute the cell-division system of the Crenarchaea, in a protein machinery that is closely related to the ESCRT system of eukaryotes. The CdvB paralog CdvB1 is believed to play a major role in the constricting ring that is the central actor in cell division in the crenarchaea. Here, we present an in vitro study of purified CdvB1 from the crenarchaeon M. sedula with a combination of TEM imaging and biochemical assays. We show that CdvB1 self-assembles into filamentous polymers that are depolymerized by the action of the Vps4-homolog ATPase CdvC. Using liposome flotation assays, we show that CdvB1 binds to negatively charged lipid membranes and can be detached from the membrane by the action of CdvC. Interestingly, we find that the polymerization and the membrane binding are mutually exclusive properties of the protein. Our findings provide novel insight into one of the main components of the archaeal cell division machinery.
{"title":"The archaeal division protein CdvB1 assembles into polymers that are depolymerized by CdvC","authors":"Alberto Blanch Jover, Nicola de Franceschi, D. Fenel, W. Weissenhorn, C. Dekker","doi":"10.1002/1873-3468.14324","DOIUrl":"https://doi.org/10.1002/1873-3468.14324","url":null,"abstract":"The Cdv proteins constitute the cell-division system of the Crenarchaea, in a protein machinery that is closely related to the ESCRT system of eukaryotes. The CdvB paralog CdvB1 is believed to play a major role in the constricting ring that is the central actor in cell division in the crenarchaea. Here, we present an in vitro study of purified CdvB1 from the crenarchaeon M. sedula with a combination of TEM imaging and biochemical assays. We show that CdvB1 self-assembles into filamentous polymers that are depolymerized by the action of the Vps4-homolog ATPase CdvC. Using liposome flotation assays, we show that CdvB1 binds to negatively charged lipid membranes and can be detached from the membrane by the action of CdvC. Interestingly, we find that the polymerization and the membrane binding are mutually exclusive properties of the protein. Our findings provide novel insight into one of the main components of the archaeal cell division machinery.","PeriodicalId":50454,"journal":{"name":"FEBS Letters","volume":"596 1","pages":"958 - 969"},"PeriodicalIF":3.5,"publicationDate":"2021-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45665732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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