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Sauer F, Sydow C, Trapp O. A robust sheath-flow CE-MS interface for hyphenation with Orbitrap MS. Electrophoresis 2020; 41:1280-1286. [PMID: 32358866 DOI: 10.1002/elps.202000044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 11/10/2022]
Abstract
The hyphenation of capillary electrophoresis with high-resolution mass spectrometry, such as Orbitrap MS, is of broad interest for the unambiguous and exceptionally sensitive identification of compounds. However, the coupling of these techniques requires a robust ionization interface that does not influence the stability of the separation voltage while coping with oxidation of the emitter tip at large ionization voltages. Herein, we present the design of a sheath-flow CE-ESI-MS interface which combines a robust and easy to operate set-up with high-resolution Orbitrap MS detection. The sheath liquid interface is equipped with a gold coated electrospray emitter which increases the stability and overall lifetime of the system. For the characterization of the interface, the spray stability and durability were investigated in dependence of the sheath-flow rate, electrospray voltage, and additional gold coating. The optimized conditions were applied to a separation of angiotensin II and neurotensin resulting in LODs of 2.4 and 3.5 ng/mL.
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Sauer F, Sydow C, Trapp O. Front cover: A robust sheath‐flow CE‐MS interface for hyphenation with Orbitrap MS. Electrophoresis 2020. [DOI: 10.1002/elps.202070082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Siebert M, Sure R, Deglmann P, Closs AC, Lucas F, Trapp O. Mechanistic Investigation into the Acetate-Initiated Catalytic Trimerization of Aliphatic Isocyanates: A Bicyclic Ride. J Org Chem 2020; 85:8553-8562. [PMID: 32508101 DOI: 10.1021/acs.joc.0c00944] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The acetate-initiated aliphatic isocyanate trimerization to isocyanurate was investigated by state-of-the-art analytical and computational methods. Although the common cyclotrimerization mechanism assumes the consecutive addition of three equivalents of isocyanate to acetate prior to product formation, we found that the underlying mechanism is more complex. In this work, we demonstrate that the product, in fact, is formed via the connection of two unexpected catalytic cycles, with acetate being only the precatalyst. The initial discovery of a precatalyst activation by quantum chemical computations and the resulting first catalysis cycle were corroborated by mass spectrometric and NMR experiments, thereby additionally revealing a catalyst migration to the second catalytic cycle. These results were further confirmed by computations, completing the full mechanistic understanding of this catalytic system. Identification of a side product with undesired properties for final coating applications allows for process optimization in the chemical industry.
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Siebert M, Storch G, Trapp O. A Fast and Reliable Screening Setup for Homogeneous Catalysis with Gaseous Reactants at Extreme Temperatures and Pressures. Org Process Res Dev 2020. [DOI: 10.1021/acs.oprd.0c00192] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Oda R, Crassous J, Berova N, Pescitelli G, Trapp O. Special issue: Proceedings of 31st International Symposium on Chirality, Bordeaux, 2019. Chirality 2020; 32:1035-1036. [PMID: 32469440 DOI: 10.1002/chir.23238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 04/28/2020] [Indexed: 11/12/2022]
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Baumann AN, Reiners F, Siegle AF, Mayer P, Trapp O, Didier D. Thiete Dioxides as Templates Towards Twisted Scaffolds and Macrocyclic Structures. Chemistry 2020; 26:6029-6035. [PMID: 32119146 PMCID: PMC7318563 DOI: 10.1002/chem.201905751] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/14/2020] [Indexed: 11/07/2022]
Abstract
Thiete dioxide units have been employed as a template for further functionalization through C-H activation strategies. Using simple thiete dioxide building blocks, a new library of axially chiral molecules has been synthesized that owe their stability to electrostatic interactions in the solid state. Similar starting materials were further engaged in the formation of cyclic trimeric structures, opening the pathway to unprecedented macrocyclic ring systems.
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von Rüden C, Trapp O, Augat P, Stuby FM, Friederichs J. Evolution of imaging in surgical fracture management. Injury 2020; 51 Suppl 2:S51-S56. [PMID: 31706585 DOI: 10.1016/j.injury.2019.10.080] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/20/2019] [Accepted: 10/22/2019] [Indexed: 02/02/2023]
Abstract
Intraoperative imaging has been advanced substantially over the last decades. It supports localization of the region of interest, verification of the preoperatively classified fracture pattern, identification of correct insertion point of the implant, placement of instruments and fixation material, and verification of correct fracture reduction and implant positioning. While conventional fluoroscopic 2D imaging remains the gold standard in intraoperative imaging, critical anatomical regions are predestined for intraoperative 3D imaging. Additional options such as perioperative virtual planning, simulation, and surgical training, 3D printing techniques and 3D augmented reality visualization may potentially open new windows to improve surgical results in fracture care. This manuscript presents an update on current and upcoming imaging techniques in orthopaedic and trauma surgery focusing on technical advances for decreasing malreduction, malalignment, and malposition, as well as tips and tricks for daily surgical practice in order to improve clinical outcomes and patients' and surgeons' safety.
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Harada N, Monde K, Kurtan T, Borhan B, Berova N, Pescitelli G, Trapp O. Publication of Chirality special issue in memory and honor of Professor Koji Nakanishi (1925-2019). Chirality 2020; 32:421-422. [PMID: 32125027 DOI: 10.1002/chir.23181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 11/07/2022]
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Siebert M, Krennrich G, Seibicke M, Siegle AF, Trapp O. Identifying high-performance catalytic conditions for carbon dioxide reduction to dimethoxymethane by multivariate modelling. Chem Sci 2019; 10:10466-10474. [PMID: 32153745 PMCID: PMC7012071 DOI: 10.1039/c9sc04591k] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 10/23/2019] [Indexed: 12/20/2022] Open
Abstract
In times of a warming climate due to excessive carbon dioxide production, catalytic conversion of carbon dioxide to formaldehyde is not only a process of great industrial interest, but it could also serve as a means for meeting our climate goals. Currently, formaldehyde is produced in an energetically unfavourable and atom-inefficient process. A much needed solution remains academically challenging. Here we present an algorithmic workflow to improve the ruthenium-catalysed transformation of carbon dioxide to the formaldehyde derivative dimethoxymethane. Catalytic processes are typically optimised by comprehensive screening of catalysts, substrates, reaction parameters and additives to enhance activity and selectivity. The common problem of the multidimensionality of the parameter space, leading to only incremental improvement in laborious physical investigations, was overcome by combining elements from machine learning, optimisation and experimental design, tripling the turnover number of 786 to 2761. The optimised conditions were then used in a new reaction setup tailored to the process parameters leading to a turnover number of 3874, exceeding by far those of known processes.
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Scholtes JF, Trapp O. Design and synthesis of a stereodynamic catalyst with reversal of selectivity by enantioselective self-inhibition. Chirality 2019; 31:1028-1042. [PMID: 31646689 DOI: 10.1002/chir.23132] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 12/13/2022]
Abstract
Chirality plays a pivotal role in an uncountable number of biological processes, and nature has developed intriguing mechanisms to maintain this state of enantiopurity. The strive for a deeper understanding of the different elements that constitute such self-sustaining systems on a molecular level has sparked great interest in the studies of autoinductive and amplifying enantioselective reactions. The design of these reactions remains highly challenging; however, the development of generally applicable principles promises to have a considerable impact on research of catalyst design and other adjacent fields in the future. Here, we report the realization of an autoinductive, enantioselective self-inhibiting hydrogenation reaction. Development of a stereodynamic catalyst with chiral sensing abilities allowed for a chiral reaction product to interact with the catalyst and change its selectivity in order to suppress its formation, which caused a reversal of selectivity over time.
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Hierholzer C, Friederichs J, Augat P, Woltmann A, Trapp O, Bühren V, von Rüden C. [Evolution and principles of intramedullary locked nailing]. Unfallchirurg 2019; 121:239-255. [PMID: 29464295 DOI: 10.1007/s00113-018-0461-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Key factors for successful osteosynthetic fracture stabilization are anatomical fracture reduction, restoration of axis and torsion alignment as well as tissue-preserving operative techniques. In long bone fractures, the use of intramedullary long bridging nailing offers ideal conditions for bone healing, as axial and rotational stability is provided by canal-filling nails and locking screws. In addition, the tissue in the fracture region is protected as the intramedullary nail insertion is distant from the fracture. The indication spectrum for modern intramedullary locked nailing includes diaphyseal fractures of long bones, metaphyseal fractures and reconstructions, as well as treatment of nonunion, osteotomy and arthrodesis of the lower extremities. Continuous improvements in nail design and instrumentation as well as the introduction of anatomical reconstruction nails will optimize the spectrum and effectiveness of intramedullary osteosynthesis even further.
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Scholtes JF, Trapp O. Enantioselectivity Induced by Stereoselective Interlocking: A Novel Core Motif for Tropos Ligands. Chemistry 2019; 25:11707-11714. [PMID: 31336015 PMCID: PMC7522685 DOI: 10.1002/chem.201902017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Indexed: 11/09/2022]
Abstract
Well-defined supramolecular interactions are a powerful tool to control the stereochemistry of a catalytic reaction. In this paper, we report a novel core motif for fluxional 2,2'-biphenyl ligands carrying (S)-amino acid-derived interaction sites in 5,5'-position that cause spontaneous enrichment of the Rax rotamer. The process is based on strong non-covalent interlocking between interaction sites, which causes diastereoselective formation of a supramolecular ligand dimer, in which the axial chirality of the two subunits is dictated by the stereochemical information in the amino acid residues. The detailed structure of the dimer was elucidated by NMR spectroscopy and single-crystal X-ray analysis. Three different phosphorus-based ligand types, namely a bisphosphine, a bisphosphinite and a phosphoramidite were synthesized and characterized. Whereas the first one was found to exist in a strongly weighted equilibrium, the two others each exhibited stereoconvergent behavior transforming into the diastereopure Rax rotamer. Enriched ligands were used in rhodium-mediated asymmetric hydrogenation reactions of prochiral olefins in which very high enantioselectivities of up to 96:4 were achieved.
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Eisenmann B, Czemmel S, Ziegler T, Buchholz G, Kortekamp A, Trapp O, Rausch T, Dry I, Bogs J. Rpv3-1 mediated resistance to grapevine downy mildew is associated with specific host transcriptional responses and the accumulation of stilbenes. BMC PLANT BIOLOGY 2019; 19:343. [PMID: 31387524 PMCID: PMC6685164 DOI: 10.1186/s12870-019-1935-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/11/2019] [Indexed: 05/05/2023]
Abstract
BACKGROUND European grapevine cultivars (Vitis vinifera spp.) are highly susceptible to the downy mildew pathogen Plasmopara viticola. Breeding of resistant V. vinifera cultivars is a promising strategy to reduce the impact of disease management. Most cultivars that have been bred for resistance to downy mildew, rely on resistance mediated by the Rpv3 (Resistance to P. viticola) locus. However, despite the extensive use of this locus, little is known about the mechanism of Rpv3-mediated resistance. RESULTS In this study, Rpv3-mediated defense responses were investigated in Rpv3+ and Rpv3- grapevine cultivars following inoculation with two distinct P. viticola isolates avrRpv3+ and avrRpv3-, with the latter being able to overcome Rpv3 resistance. Based on comparative microscopic, metabolomic and transcriptomic analyses, our results show that the Rpv3-1-mediated resistance is associated with a defense mechanism that triggers synthesis of fungi-toxic stilbenes and programmed cell death (PCD), resulting in reduced but not suppressed pathogen growth and development. Functional annotation of the encoded protein sequence of genes significantly upregulated during the Rpv3-1-mediated defense response revealed putative roles in pathogen recognition, signal transduction and defense responses. CONCLUSION This study used histochemical, transcriptomic and metabolomic analyses of Rpv3+ and susceptible cultivars inoculated with avirulent and virulent P. viticola isolates to investigate mechanism underlying the Rpv3-1-mediated resistance response. We demonstrated a strong correlation between the expressions of stilbene biosynthesis related genes, the accumulation of fungi-toxic stilbenes, pathogen growth inhibition and PCD.
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Teichert JS, Kruse FM, Trapp O. Direct Prebiotic Pathway to DNA Nucleosides. Angew Chem Int Ed Engl 2019; 58:9944-9947. [PMID: 31131499 DOI: 10.1002/anie.201903400] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/23/2019] [Indexed: 11/11/2022]
Abstract
It is assumed that RNA played a key role in the origin of life, and the transition to more complex but more stable DNA for continuous information storage and replication requires the development of a ribonucleotide reductase to obtain the deoxyribonucleotides from ribonucleotides. This step, as well as an alternative path from abiotic molecules to DNA-based life is completely unknown. Shown here is the formation of deoxyribonucleosides under relevant prebiotic conditions in water in high regio- and stereoselectivity, from all canonical purine and pyrimidine bases, by condensation with acetaldehyde and sugar-forming precursors. Thus, a continuous path to deoxyribonucleosides, starting from simple, prebiotically available molecules has been discovered. Furthermore, the deoxyapionucleosides (DApiNA) were identified as a potential DNA progenitor. The results suggest that the DNA world evolved much earlier than previously assumed.
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Wunsch MR, Reiter AMC, Schuster FS, Lehnig R, Trapp O. Continuous online process analytics with multiplexing gas chromatography by using calibrated convolution matrices. J Chromatogr A 2019; 1595:180-189. [PMID: 30803787 DOI: 10.1016/j.chroma.2019.02.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 02/11/2019] [Accepted: 02/14/2019] [Indexed: 11/26/2022]
Abstract
The development of fast and precise measurement techniques for process analytical technology is important to operate chemical processes safely and efficiently. For quantitative measurements of multiple components at a trace level, often gas chromatographic methods are used which have a response time of several minutes or of up to one hour. For fast changing processes, this can be too slow for efficient control. For reducing the dead time of a control loop by increasing the measurement frequency, a multiplexing gas chromatography (mpGC) technique for a chromatographic system exhibiting a systematic non-linear response has been developed. For mpGC, superimposed chromatograms are measured by injecting consecutive samples before all components of previous samples have eluted from the column. The deconvolution of a superimposed chromatogram yields a computed chromatogram which is an average over the single chromatograms forming the superimposed chromatogram. Such a computed chromatogram typically shows so called correlation noise depending on the degree by which the single chromatograms forming the superimposed chromatogram will differ from each other (non-linear response). A technique is presented to calibrate the convolution matrix in order to suppress correlation noise introduced by systematic errors of the chromatographic system. The remaining correlation noise in the computed chromatogram is then exclusively caused by changing concentrations in the sample stream. For the method presented here, the sample is injected five times during the run time of a single chromatogram. The computed chromatogram is obtained three times within this timespan while representing each time an averaged chromatogram over the last five injections. Therefore, the sample throughput is increased by a factor of three compared to conventional GC.
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Lamour S, Pallmann S, Haas M, Trapp O. Prebiotic Sugar Formation Under Nonaqueous Conditions and Mechanochemical Acceleration. Life (Basel) 2019; 9:life9020052. [PMID: 31226799 PMCID: PMC6617062 DOI: 10.3390/life9020052] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 06/17/2019] [Accepted: 06/18/2019] [Indexed: 12/26/2022] Open
Abstract
Monosaccharides represent one of the major building blocks of life. One of the plausible prebiotic synthesis routes is the formose network, which generates sugars from C1 and C2 carbon sources in basic aqueous solution. We report on the feasibility of the formation of monosaccharides under physical forces simulated in a ball mill starting from formaldehyde, glycolaldehyde, DL-glyceraldehyde as prebiotically available substrates using catalytically active, basic minerals. We investigated the influence of the mechanic energy input on our model system using calcium hydroxide in an oscillatory ball mill. We show that the synthesis of monosaccharides is kinetically accelerated under mechanochemical conditions. The resulting sugar mixture contains monosaccharides with straight and branched carbon chains as well as decomposition products. In comparison to the sugar formation in water, the monosaccharides formed under mechanochemical conditions are more stable and selectively synthesized. Our results imply the possibility of a prebiotic monosaccharide origin in geochemical environments scant or devoid of water promoted by mechanochemical forces such as meteorite impacts or lithospheric activity.
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Scholtes JF, Trapp O. Supramolecular Interlocked Biphenyl Ligands for Enantioselective Ti-Catalyzed Alkylation of Aromatic Aldehydes. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00262] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Dorn A, Feller L, Castri D, Röhrig S, Enderle J, Herrmann NJ, Block-Schmidt A, Trapp O, Köhler L, Puchta H. An Arabidopsis FANCJ helicase homologue is required for DNA crosslink repair and rDNA repeat stability. PLoS Genet 2019; 15:e1008174. [PMID: 31120885 PMCID: PMC6550410 DOI: 10.1371/journal.pgen.1008174] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/05/2019] [Accepted: 05/03/2019] [Indexed: 11/18/2022] Open
Abstract
Proteins of the Fanconi Anemia (FA) complementation group are required for crosslink (CL) repair in humans and their loss leads to severe pathological phenotypes. Here we characterize a homolog of the Fe-S cluster helicase FANCJ in the model plant Arabidopsis, AtFANCJB, and show that it is involved in interstrand CL repair. It acts at a presumably early step in concert with the nuclease FAN1 but independently of the nuclease AtMUS81, and is epistatic to both error-prone and error-free post-replicative repair in Arabidopsis. The simultaneous knock out of FANCJB and the Fe-S cluster helicase RTEL1 leads to induced cell death in root meristems, indicating an important role of the enzymes in replicative DNA repair. Surprisingly, we found that AtFANCJB is involved in safeguarding rDNA stability in plants. In the absence of AtRTEL1 and AtFANCJB, we detected a synergetic reduction to about one third of the original number of 45S rDNA copies. It is tempting to speculate that the detected rDNA instability might be due to deficiencies in G-quadruplex structure resolution and might thus contribute to pathological phenotypes of certain human genetic diseases.
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Seibicke M, Siebert M, Siegle AF, Gutenthaler SM, Trapp O. Application of Hetero-Triphos Ligands in the Selective Ruthenium-Catalyzed Transformation of Carbon Dioxide to the Formaldehyde Oxidation State. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00107] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Enderle J, Dorn A, Beying N, Trapp O, Puchta H. The Protease WSS1A, the Endonuclease MUS81, and the Phosphodiesterase TDP1 Are Involved in Independent Pathways of DNA-protein Crosslink Repair in Plants. THE PLANT CELL 2019; 31:775-790. [PMID: 30760561 PMCID: PMC6501609 DOI: 10.1105/tpc.18.00824] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/08/2019] [Accepted: 02/11/2019] [Indexed: 05/04/2023]
Abstract
DNA-protein crosslinks (DPCs) represent a severe threat to the genome integrity; however, the main mechanisms of DPC repair were only recently elucidated in humans and yeast. Here we define the pathways for DPC repair in plants. Using CRISPR/Cas9, we could show that only one of two homologs of the universal repair proteases SPARTAN/ weak suppressor of smt3 (Wss1), WSS1A, is essential for DPC repair in Arabidopsis (Arabidopsis thaliana). WSS1A defective lines exhibit developmental defects and are hypersensitive to camptothecin (CPT) and cis-platin. Interestingly, the CRISPR/Cas9 mutants of TYROSYL-DNA PHOSPHODIESTERASE 1 (TDP1) are insensitive to CPT, and only the wss1A tdp1 double mutant reveals a higher sensitivity than the wss1A single mutant. This indicates that TDP1 defines a minor backup pathway in the repair of DPCs. Moreover, we found that knock out of the endonuclease METHYL METHANESULFONATE AND UV SENSITIVE PROTEIN 81 (MUS81) results in a strong sensitivity to DPC-inducing agents. The fact that wss1A mus81 and tdp1 mus81 double mutants exhibit growth defects and an increase in dead cells in root meristems after CPT treatment demonstrates that there are three independent pathways for DPC repair in Arabidopsis. These pathways are defined by their different biochemical specificities, as main actors, the DNA endonuclease MUS81 and the protease WSS1A, and the phosphodiesterase TDP1 as backup.
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Scholtes JF, Trapp O. Inducing Enantioselectivity in a Dynamic Catalyst by Supramolecular Interlocking. Angew Chem Int Ed Engl 2019; 58:6306-6310. [PMID: 30786123 DOI: 10.1002/anie.201901175] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 02/19/2019] [Indexed: 12/19/2022]
Abstract
The design of a new class of fluxional biphenyl bisphosphinite (BIBIPHOS) ligands decorated with amino acid-based diamide interaction sites is reported that undergo spontaneous desymmetrization. Hydrogenation of prochiral alkenes using Rh-BIBIPHOS results in enantiomeric ratios of up to 96:4 (R/S). This stereoconvergent behavior of the fluxional BIBIPHOS ligand is triggered by pronounced intermolecular interlocking of the recognition sites, leading to the formation of a supramolecular assembly, where the axial orientation of the biphenyl ligand backbone is governed by the chirality of the amino acid moieties. Stereoinduction during catalysis is decoupled from this process and occurs as an immediate consequence of the emergent behavior of the ligands. This supramolecular system is very robust and has the potential to be adopted for other ligand designs in enantioselective catalysis.
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Scholtes JF, Trapp O. Inducing Enantioselectivity in a Dynamic Catalyst by Supramolecular Interlocking. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201901175] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Albert S, Chen Z, Keppler K, Lerch P, Quack M, Schurig V, Trapp O. The Gigahertz and Terahertz spectrum of monodeutero-oxirane (c-C 2H 3DO). Phys Chem Chem Phys 2019; 21:3669-3675. [PMID: 30444517 DOI: 10.1039/c8cp05311a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The rotational spectrum of monodeutero-oxirane was analysed as measured using the Zurich Gigahertz (GHz) spectrometer and our highest resolution Fourier Transform Infrared (FTIR) spectrometer system coupled to synchrotron radiation at the Swiss Light Source (SLS). 112 distinct line frequencies have been newly assigned in the GHz range (extended to 120 GHz, compared to previous work extending to only 59 GHz) including rotational states up to J = 23. We have furthermore assigned 398 lines in the far infrared or Terahertz range (0.75-2.10 THz or 25-70 cm-1) including transitions with rotational quantum numbers up to J = 59. The results are discussed in relation to the possible first astrophysical observation of an isotopically chiral molecule and in relation to molecular parity violation.
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de Souza A, Brighenti A, Brighenti E, Caliari V, Stefanini M, Trapp O, Gardin J, Dalbó M, Welter L, Camargo S. Performance of resistant varieties (PIWI) at two different altitudes in Southern Brazil. BIO WEB OF CONFERENCES 2019. [DOI: 10.1051/bioconf/20191201021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In southern Brazil there is a predominance of labrusca and hybrid varieties for wine and juice production due to climatic conditions of high rainfall, temperature and relative humidity. Growing varieties that combine disease resistance and wine quality (PIWI) can be an alternative to improve wine quality. The objective of this work was to evaluate the performance of three PIWI varieties (Felicia, Calardis Blanc and Aromera) in two regions (Videira, 27∘01′S and 51∘08′W, altitude 830 m; and São Joaquim, 28∘13′S and 50∘04′W, altitude 1100 m) in the vintage 2018. The date of occurrence of main phenological stages, productiveindexes, clusters characteristics and grape qualitative indexes was evaluated. There was no difference for budbreak date, but flowering, veraison an maturity time varied between regions. The development of plants is slower when they are cultivated at a higher altitude. The number of clusters per plant and yield were higher at 830 m for all varieties. For productive indexes Felicia and Calardis Blanc varieties stood out in relation to Aromera in all parameters. Among the evaluated varieties, Felicia and Calardis Blanc were better adapted to the lower altitude region and had higher productivity and the same grape quality. On the other hand, Aromera presented higher productivity at 830 m but higher soluble solids content at 1100 m.
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