TY - JOUR A1 - Hahn, Aaron A1 - Engelhard, Christopher A1 - Reschke, Stefan A1 - Teutloff, Christian A1 - Bittl, Robert A1 - Leimkühler, Silke A1 - Risse, Thomas T1 - Structural Insights into the Incorporation of the Mo Cofactor into Sulfite Oxidase from Site-Directed Spin Labeling JF - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition N2 - Mononuclear molybdoenzymes catalyze a broad range of redox reactions and are highly conserved in all kingdoms of life. This study addresses the question of how the Mo cofactor (Moco) is incorporated into the apo form of human sulfite oxidase (hSO) by using site-directed spin labeling to determine intramolecular distances in the nanometer range. Comparative measurements of the holo and apo forms of hSO enabled the localization of the corresponding structural changes, which are localized to a short loop (residues 263-273) of the Moco-containing domain. A flap-like movement of the loop provides access to the Moco binding-pocket in the apo form of the protein and explains the earlier studies on the in vitro reconstitution of apo-hSO with Moco. Remarkably, the loop motif can be found in a variety of structurally similar molybdoenzymes among various organisms, thus suggesting a common mechanism of Moco incorporation. KW - biocatalysis KW - cofactors KW - enzymes KW - EPR spectroscopy KW - protein structures Y1 - 2015 U6 - https://doi.org/10.1002/anie.201504772 SN - 1433-7851 SN - 1521-3773 VL - 54 IS - 40 SP - 11865 EP - 11869 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Hahn, Aaron A1 - Reschke, Stefan A1 - Leimkühler, Silke A1 - Risse, Thomas T1 - Ketoxime coupling of p-Acetylphenylalanine at neutral pH for site-directed spin labeling of human sulfite oxidase JF - The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces & biophysical chemistry N2 - Site-directed spin labeling of the unnatural amino acid p-acetylphenylalanine (p-AcPhe) using oxime based coupling chemistry is successfully applied to investigate human sulfite oxidase (hSO), a protein containing an essential cysteine residue, which impedes the use of thiol based coupling chemistry. The protein was found to be sensitive toward typical reaction conditions of oxime coupling, namely, acidic reaction conditions and elevated temperatures. Thus, coupling at neutral pH and room temperature is mandatory. Three catalysts described in the literature to accelerate the reaction rate have been tested. Best spin labeling efficiencies were observed for p-methoxyaniline, while the other catalysts described in the literature to have even better performance for oxime coupling at neutral pH were substantially less active or led to precipitation of the protein. A clear correlation of spin labeling efficiency with the local environment of the residue is found, shedding some light on the importance of the sterically demanding reaction complex between p-AcPhe, the aniline catalyst, and the spin label for the reaction rate. The analysis of the line shape has shown that its interpretation in terms of local environment is more challenging as compared to the well-established spin labels based on cysteine chemistry. To this end the results presented here indicate that the larger steric demand of the spin labeled p-AcPhe can induce structural effects instead of reporting on them. Y1 - 2014 U6 - https://doi.org/10.1021/jp503471j SN - 1520-6106 VL - 118 IS - 25 SP - 7077 EP - 7084 PB - American Chemical Society CY - Washington ER - TY - GEN A1 - Esguerra, Alejandro A1 - Helmerich, Nicole A1 - Risse, Thomas T1 - Introduction T2 - Sustainability Politics and Limited Statehood: Contesting the New Modes of Governance N2 - The Paris Agreement for Climate Change or the Sustainable Development Goals (SDGs) rely on new modes of governance for implementation. Indeed, new modes of governance such as market-based instruments, public-private partnerships or multi-stakeholder initiatives have been praised for playing a pivotal role in effective and legitimate sustainability governance. Yet, do they also deliver in areas of limited statehood? States such as Malaysia or the Dominican Republic partly lack the ability to implement and enforce rules; their statehood is limited. This introduction provides the analytical framework of this volume and critically examines the performance of new modes of governance in areas of limited statehood, drawing on the book’s in-depth case studies on issues of climate change, biodiversity, and health. Y1 - 2016 SN - 978-3-319-39871-6 SN - 978-3-319-39870-9 U6 - https://doi.org/10.1007/978-3-319-39871-6_1 SP - 1 EP - 22 PB - Palgrave Macmillan, Cham CY - Basingstoke ER - TY - GEN A1 - Risse, Thomas T1 - Die unipolare Weltordnung - Ein soziales Konstrukt : ein Kommentar zu den Kommentaren N2 - In this issue, we continue and complete the debate on the future of the transatlantic relationship and of world order after the Iraq war. The debate was initiated by an article by Thomas Risse (Freie Universität Berlin) in WeltTrends 39, which has provoked a remarkable reaction within the German academic community, as documented in WeltTrends 40. This issue features additional comments and the rebuttal by Thomas Risse. Most authors believe that the transatlantic partnership is in a serious crisis, but claim that it remains without an alternative for both sides of the Atlantic. KW - US foreign policy KW - European foreign policy KW - Germany KW - transatlantic relations KW - Iraq war Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-9631 ER - TY - GEN A1 - Risse, Thomas T1 - Die neue Weltordnung : US-amerikanische Hypermacht - europäische Ohnmacht? N2 - Do the transatlantic relations have a future after the Iraq crisis and what will they look like? This question will be discussed in this and the next issue of WeltTrends. For this debate, Thomas Risse, Chair of International Relation at the Freie Universität Berlin, provides the initial input. Risse focuses on controversial issues inside of Europe, the outcome of which will be decisive for the future of the transatlantic relationship. Will the European consensus once constituted by the commitment to international law and multilateralism persist? What is the European position regarding democracy and human rights in the Middle East? Will Europe develop a strategy to cope with the new kind of threats posed by weapons of mass destruction in the hands of dictators or terrorists? Risse´s article has provoked a debate inside the German academic community, whose contributions will be published in the next issue of WeltTrends. KW - Iraq crisis KW - world order KW - transatlantic relations Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-9580 ER -