1
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Nybro Dansholm C, Meier S, Beeren SR. Amylose Dimerization in Solution Can Be Studied Using a Model System. Chembiochem 2024; 25:e202300832. [PMID: 38220779 DOI: 10.1002/cbic.202300832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/05/2024] [Accepted: 01/12/2024] [Indexed: 01/16/2024]
Abstract
Amylose, the linear polymer of α-1,4-linked glucopyranose units, is known to crystallize as a parallel double helix, but evidence of this duplex forming in solution has remained elusive for decades. We show how the dimerization of short amylose chains can be detected in solution using NMR spectroscopy when the glucans are labeled at the reducing-end with an aromatic moiety that overcomes chemical shift degeneracy leading to distinct signals for the single-stranded and duplex amylose. A set of α-1,4 glucans with varying lengths of 6, 12, 18, and 22 glucose units and a 4-aminobenzamide label were synthesized, enabling the first systematic thermodynamic study of the association of amylose in solution. The dimerization is enthalpically driven, entropically unfavorable and beyond a minimum length of 12, each additional pair of glucose residues stabilizes the duplex by 0.85 kJ mol-1 . This fundamental knowledge provides a basis for a quantitative understanding of starch structure, gelation and enzymatic digestion, and lays the foundations for the strategic use of α-1,4-glucans in the development of self-assembled materials.
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Affiliation(s)
- Charlotte Nybro Dansholm
- Department of Chemistry, Technical University of Denmark, Kemitorvet Building 207, Kongens Lyngby, DK-2800, Denmark
| | - Sebastian Meier
- Department of Chemistry, Technical University of Denmark, Kemitorvet Building 207, Kongens Lyngby, DK-2800, Denmark
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark, Kemitorvet Building 207, Kongens Lyngby, DK-2800, Denmark
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2
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Larsen D, Erichsen A, Masciotta G, Meier S, Beeren SR. Quantitative determination of the binding capabilities of individual large-ring cyclodextrins in complex mixtures. Chem Commun (Camb) 2024; 60:2090-2093. [PMID: 38294022 DOI: 10.1039/d3cc05897b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Large-ring cyclodextrins (CDs) are a comparatively unexplored family of macrocycles. We use high-resolution 1H-13C HSQC NMR experiments to resolve the anomeric signals of at least 13 different size CDs in a mixture. Using a single titration experiment, we can quantify the individual binding capabilites of these structurally-related hosts, avoiding the need for cumbersome isolation.
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Affiliation(s)
- Dennis Larsen
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kongens Lyngby, Denmark.
| | - Andreas Erichsen
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kongens Lyngby, Denmark.
| | - Giorgia Masciotta
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kongens Lyngby, Denmark.
| | - Sebastian Meier
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kongens Lyngby, Denmark.
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kongens Lyngby, Denmark.
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3
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Sørensen J, Hansen EL, Larsen D, Elmquist MA, Buchleithner A, Florean L, Beeren SR. Light-controlled enzymatic synthesis of γ-CD using a recyclable azobenzene template. Chem Sci 2023; 14:7725-7732. [PMID: 37476725 PMCID: PMC10355107 DOI: 10.1039/d3sc01997g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 06/19/2023] [Indexed: 07/22/2023] Open
Abstract
Cyclodextrins (CDs) are important molecular hosts for hydrophobic guests in water and extensively employed in the pharmaceutical, food and cosmetic industries to encapsulate drugs, flavours and aromas. Compared with α- and β-CD, the wide-scale use of γ-CD is currently limited due to costly production processes. We show how the yield of γ-CD in the enzymatic synthesis of CDs can be increased 5-fold by adding a tetra-ortho-isopropoxy-substituted azobenzene template irradiated at 625 nm (to obtain the cis-(Z)-isomer) to direct the synthesis. Following the enzymatic reaction, the template can then be readily recovered from the product mixture for use in subsequent reaction cycles. Heating induces thermal cis-(Z) to trans-(E) relaxation and consequent dissociation from γ-CD whereupon the template can then be precipitated by acidification. For this study we designed and synthesised a set of three water-soluble azobenzene templates with different ortho-substituents and characterised their photoswitching behaviour using UV/vis and NMR spectroscopy. The templates were tested in cyclodextrin glucanotransferase-mediated dynamic combinatorial libraries (DCLs) of cyclodextrins while irradiating at different wavelengths to control the cis/trans ratios. To rationalise the behaviour of the DCLs, NMR titrations were carried out to investigate the binding interactions between α-, β- and γ-CD and the cis and trans isomers of each template.
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Affiliation(s)
- Juliane Sørensen
- Department of Chemistry, Technical University of Denmark Kemitorvet Building 207 Kongens Lyngby 2800 Denmark
| | - Emilie Ljungberg Hansen
- Department of Chemistry, Technical University of Denmark Kemitorvet Building 207 Kongens Lyngby 2800 Denmark
| | - Dennis Larsen
- Department of Chemistry, Technical University of Denmark Kemitorvet Building 207 Kongens Lyngby 2800 Denmark
| | - Mathias Albert Elmquist
- Department of Chemistry, Technical University of Denmark Kemitorvet Building 207 Kongens Lyngby 2800 Denmark
| | - Andreas Buchleithner
- Department of Chemistry, Technical University of Denmark Kemitorvet Building 207 Kongens Lyngby 2800 Denmark
| | - Luca Florean
- Department of Chemistry, Technical University of Denmark Kemitorvet Building 207 Kongens Lyngby 2800 Denmark
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark Kemitorvet Building 207 Kongens Lyngby 2800 Denmark
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4
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Abstract
While α-, β-, and γ-cyclodextrin (CD) are ubiquitous hosts employed by supramolecular chemists, δ-CD (formed from nine α-1,4-linked glucopyranose units) has received very little attention. α-, β-, and γ-CD are the major products of the enzymatic breakdown of starch by cyclodextrin glucanotransferase (CGTase), but δ-CD forms only transiently in this reaction, as a minor component of a complex mixture of linear and cyclic glucans. In this work, we show how δ-CD can be synthesized in unprecedented yields by employing a bolaamphiphile template in an enzyme-mediated dynamic combinatorial library of cyclodextrins. NMR spectroscopy studies revealed that δ-CD can thread up to three bolaamphiphiles forming [2]-, [3]-, or [4]-pseudorotaxanes, depending on the size of the hydrophilic headgroup and the length of the alkyl chain axle. Threading of the first bolaamphiphile occurs in fast exchange on the NMR chemical shift time scale, while subsequent threading occurs in slow exchange. To extract quantitative information for 1:2 and 1:3 binding events occurring in mixed exchange regimes, we derived equations for nonlinear curve fitting that take into consideration both the chemical shift changes for species in fast exchange and the integrals for species in slow exchange to determine Ka1, Ka2, and Ka3. Template T1 could be used to direct the enzymatic synthesis of δ-CD due to the cooperative formation of a 1:2 complex─the [3]-pseudorotaxane δ-CD·T12. Importantly, T1 is recyclable. It can be readily recovered from the enzymatic reaction by precipitation and reused in subsequent syntheses enabling preparative-scale synthesis of δ-CD.
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Affiliation(s)
- Andreas Erichsen
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Günther H J Peters
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
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5
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Samuelsen L, Larsen D, Schönbeck C, Beeren SR. pH-Responsive templates modulate the dynamic enzymatic synthesis of cyclodextrins. Chem Commun (Camb) 2022; 58:5152-5155. [PMID: 35383788 DOI: 10.1039/d1cc06554h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Product selection in the dynamic enzymatic synthesis of cyclodextrins can be controlled by changing the pH. Using cyclodextrin glucanotransferase to make labile the glycosidic linkages in cyclodextrins (CDs), we generate a dynamic combinatorial library of interconverting linear and cyclic α-1,4-glucans. Templates can be employed to favour the selective production of specific CDs and, herein, we show that by using ionisable templates, the synthesis of α-CD or β-CD can be favoured by simply changing the pH. Using 4-nitrophenol as the template, β-CD is the preferred product at low pH, while α-CD is the preferred product at high pH. Furthermore, a new methodology is described for the simulation of product distributions in dynamic combinatorial libraries with ionisable templates at any given pH.
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Affiliation(s)
- Lisa Samuelsen
- Department of Science and Environment, Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark.,Department of Chemistry, Technical University of Denmark, Kemitorvet building 207, DK-2800 Kongens Lyngby, Denmark.
| | - Dennis Larsen
- Department of Chemistry, Technical University of Denmark, Kemitorvet building 207, DK-2800 Kongens Lyngby, Denmark.
| | - Christian Schönbeck
- Department of Science and Environment, Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark, Kemitorvet building 207, DK-2800 Kongens Lyngby, Denmark.
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6
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Larsen D, Ferreira M, Tilloy S, Monflier E, Beeren SR. Unnatural cyclodextrins can be accessed from enzyme-mediated dynamic combinatorial libraries. Chem Commun (Camb) 2022; 58:2287-2290. [PMID: 35080533 DOI: 10.1039/d1cc06452e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamic systems of cyclodextrins (CDs) enabled by a native cyclodextrin glucanotransferase (CGTase) can incorporate unnatural glucopyranose-derived building blocks, expanding the applicability of enzyme-mediated dynamic combinatorial chemistry by using synthetically modified substrates. Starting dynamic combinatorial libraries from CDs with a single 6-modified glucopyranose results in a dynamic mixture of CDs containing several modified glucopyranoses. The relative concentrations of modified α, β or γ-CDs can be controlled by the addition of templates, providing a novel way to access modified CDs.
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Affiliation(s)
- Dennis Larsen
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark.
| | - Michel Ferreira
- Univ. Artois, CNRS, Centrale Lille, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Lens 62300, France
| | - Sébastien Tilloy
- Univ. Artois, CNRS, Centrale Lille, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Lens 62300, France
| | - Eric Monflier
- Univ. Artois, CNRS, Centrale Lille, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Lens 62300, France
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark.
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7
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Erichsen A, Larsen D, Beeren SR. Chaotropic and Kosmotropic Anions Regulate the Outcome of Enzyme-Mediated Dynamic Combinatorial Libraries of Cyclodextrins in Two Different Ways. Front Chem 2021; 9:721942. [PMID: 34414164 PMCID: PMC8370642 DOI: 10.3389/fchem.2021.721942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/12/2021] [Indexed: 11/22/2022] Open
Abstract
We demonstrate how different anions from across the Hofmeister series can influence the behavior of enzyme-mediated dynamic combinatorial libraries of cyclodextrins (CDs). Using cyclodextrin glucanotransferase to catalyze reversible transglycosylation, dynamic mixtures of interconverting cyclodextrins can be formed wherein the relative concentrations of α-CD, β-CD and γ-CD is determined by their intrinsic stabilities and any stabilizing influences of added template (guest) molecules. Here, we find that addition of high concentrations of kosmotropic anions can be used to enhance the effects of added hydrophobic templates, while chaotropic anions can themselves act as templates, causing predictable and significant changes in the cyclodextrin composition due to weak, but specific, binding interactions with α-CD.
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Affiliation(s)
- Andreas Erichsen
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Dennis Larsen
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, Denmark
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8
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Larsen D, Beeren SR. Building up cyclodextrins from scratch - templated enzymatic synthesis of cyclodextrins directly from maltose. Chem Commun (Camb) 2021; 57:2503-2506. [PMID: 33554997 DOI: 10.1039/d1cc00137j] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cyclodextrins (CDs) are commercially produced via enzymatic breakdown of starch or amylose. In contrast, we show that cyclodextrins can be synthesised directly from the disaccharide maltose in good yields by exploiting the use of templates to favour the enzymatic build-up of cyclodextrins. Using cyclodextrin glucanotransferase to catalyse reversible transglycosylation, and 1-adamantane carboxylic acid as the template, we can synthesise β-CD from maltose in approximately 70% yield. This work represents a step towards supramolecular control over enzymatic production of complex oligosaccharides from simple building blocks.
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Affiliation(s)
- Dennis Larsen
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark.
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark.
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9
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Larsen D, Beeren SR. Tuning the Outcome of Enzyme-Mediated Dynamic Cyclodextrin Libraries to Enhance Template Effects. Chemistry 2020; 26:11032-11038. [PMID: 32445426 DOI: 10.1002/chem.202001076] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/15/2020] [Indexed: 12/11/2022]
Abstract
Enzyme-mediated dynamic combinatorial chemistry combines the concept of thermodynamically controlled covalent self-assembly with the inherent biological relevance of enzymatic transformations. A system of interconverting cyclodextrins has been explored, in which the glycosidic linkage is rendered dynamic by the action of cyclodextrin glucanotransferase (CGTase). External factors, such as pH, temperature, solvent, and salinity are reported to modulate the composition of the dynamic cyclodextrin library. Dynamic libraries of cyclodextrins (CDs) could be obtained in wide ranges of pH (5.0-9.0), temperature (5-37 °C), and salinity (up to 7.5 m NaNO3 ), and with high organic solvent content (50 % by volume of ethanol), showing that enzyme-mediated dynamic systems can be robust and not limited to physiological conditions. Furthermore, it is demonstrated how strategic choice of reaction conditions can enhance template effects, in this case, to achieve highly selective production of α-CD, an otherwise challenging target due to competition from the structurally similar β-CD.
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Affiliation(s)
- Dennis Larsen
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800, Kongens Lyngby, Denmark
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800, Kongens Lyngby, Denmark
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10
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Larsen D, Bjerre PM, Beeren SR. Light-controlled out-of-equilibrium assembly of cyclodextrins in an enzyme-mediated dynamic system. Chem Commun (Camb) 2019; 55:15037-15040. [PMID: 31782430 DOI: 10.1039/c9cc08452e] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We show that the selective enzymatic synthesis of specific cyclodextrins can be modulated using light. We use enzyme-mediated dynamic combinatorial chemistry to generate a mixture of interconverting linear and cyclic α-1,4-glucans, and employ an azobenzene photoswitch as a template. Using UV or blue light to switch between photostationary states with different azobenzene cis/trans isomeric ratios, we can promote the out-of-equilibrium assembly of either α-cyclodextrin or β-cyclodextrin.
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Affiliation(s)
- Dennis Larsen
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kongens Lyngby, Denmark.
| | - Philip M Bjerre
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kongens Lyngby, Denmark.
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kongens Lyngby, Denmark.
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11
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Larsen D, Beeren SR. Enzyme-mediated dynamic combinatorial chemistry allows out-of-equilibrium template-directed synthesis of macrocyclic oligosaccharides. Chem Sci 2019; 10:9981-9987. [PMID: 32055354 PMCID: PMC6979337 DOI: 10.1039/c9sc03983j] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 09/02/2019] [Indexed: 12/16/2022] Open
Abstract
Artificial templates can control out-of-equilibrium self-assembly in an enzyme-mediated dynamic system of cyclodextrins, even allowing access to products not selected in Nature.
We show that the outcome of enzymatic reactions can be manipulated and controlled by using artificial template molecules to direct the self-assembly of specific products in an enzyme-mediated dynamic system. Specifically, we utilize a glycosyltransferase to generate a complex dynamic mixture of interconverting linear and macrocyclic α-1,4-d-glucans (cyclodextrins). We find that the native cyclodextrins (α, β and γ) are formed out-of-equilibrium as part of a kinetically trapped subsystem, that surprisingly operates transiently like a Dynamic Combinatorial Library (DCL) under thermodynamic control. By addition of different templates, we can promote the synthesis of each of the native cyclodextrins with 89–99% selectivity, or alternatively, we can amplify the synthesis of unusual large-ring cyclodextrins (δ and ε) with 9 and 10 glucose units per macrocycle. In the absence of templates, the transient DCL lasts less than a day, and cyclodextrins convert rapidly to short maltooligosaccharides. Templates stabilize the kinetically trapped subsystem enabling robust selective synthesis of cyclodextrins, as demonstrated by the high-yielding sequential interconversion of cyclodextrins in a single reaction vessel. Our results show that given the right balance between thermodynamic and kinetic control, templates can direct out-of-equilibrium self-assembly, and be used to manipulate enzymatic transformations to favor specific and/or alternative products to those selected in Nature.
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Affiliation(s)
- Dennis Larsen
- Department of Chemistry , Technical University of Denmark , Kemitorvet 207 , DK-2800 Kongens Lyngby , Denmark .
| | - Sophie R Beeren
- Department of Chemistry , Technical University of Denmark , Kemitorvet 207 , DK-2800 Kongens Lyngby , Denmark .
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12
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Petersen MÅ, Rasmussen B, Andersen NN, Sauer SPA, Nielsen MB, Beeren SR, Pittelkow M. Cover Feature: Molecular Switching in Confined Spaces: Effects of Encapsulating the DHA/VHF Photo-Switch in Cucurbiturils (Chem. Eur. J. 67/2017). Chemistry 2017. [DOI: 10.1002/chem.201704331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Michael Å. Petersen
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 Copenhagen Ø Denmark
| | - Brian Rasmussen
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 Copenhagen Ø Denmark
| | - Nicolaj N. Andersen
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 Copenhagen Ø Denmark
| | - Stephan P. A. Sauer
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 Copenhagen Ø Denmark
| | - Mogens Brøndsted Nielsen
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 Copenhagen Ø Denmark
| | - Sophie R. Beeren
- Department of Chemistry; Technical University of Denmark; Kemitorvet, bygning 207 2800 Kgs. Lyngby Denmark
| | - Michael Pittelkow
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 Copenhagen Ø Denmark
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13
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Shekarforoush E, Mendes AC, Baj V, Beeren SR, Chronakis IS. Electrospun Phospholipid Fibers as Micro-Encapsulation and Antioxidant Matrices. Molecules 2017; 22:E1708. [PMID: 29039789 PMCID: PMC6151585 DOI: 10.3390/molecules22101708] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 10/05/2017] [Accepted: 10/09/2017] [Indexed: 11/17/2022] Open
Abstract
Electrospun phospholipid (asolectin) microfibers were investigated as antioxidants and encapsulation matrices for curcumin and vanillin. These phospholipid microfibers exhibited antioxidant properties which increased after the encapsulation of both curcumin and vanillin. The total antioxidant capacity (TAC) and the total phenolic content (TPC) of curcumin/phospholipid and vanillin/phospholipid microfibers remained stable over time at different temperatures (refrigerated, ambient) and pressures (vacuum, ambient). ¹H-NMR confirmed the chemical stability of both encapsulated curcumin and vanillin within phospholipid fibers. Release studies in aqueous media revealed that the phenolic bioactives were released mainly due to swelling of the phospholipid fiber matrix over time. The above studies confirm the efficacy of electrospun phospholipid microfibers as encapsulation and antioxidant systems.
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Affiliation(s)
- Elhamalsadat Shekarforoush
- Nano-Bio Science Research Group, DTU-Food, Technical University of Denmark, Kemitorvet 202, 2800 Kongens Lyngby, Denmark; (E.S.); (I.S.C.)
| | - Ana C. Mendes
- Nano-Bio Science Research Group, DTU-Food, Technical University of Denmark, Kemitorvet 202, 2800 Kongens Lyngby, Denmark; (E.S.); (I.S.C.)
| | - Vanessa Baj
- Nano-Bio Science Research Group, DTU-Food, Technical University of Denmark, Kemitorvet 202, 2800 Kongens Lyngby, Denmark; (E.S.); (I.S.C.)
| | - Sophie R. Beeren
- DTU-Chemistry, Technical University of Denmark, Kemitorvet 207, 2800 Kongens Lyngby, Denmark; (V.B.); (S.R.B.)
| | - Ioannis S. Chronakis
- Nano-Bio Science Research Group, DTU-Food, Technical University of Denmark, Kemitorvet 202, 2800 Kongens Lyngby, Denmark; (E.S.); (I.S.C.)
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14
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Petersen MÅ, Rasmussen B, Andersen NN, Sauer SPA, Nielsen MB, Beeren SR, Pittelkow M. Molecular Switching in Confined Spaces: Effects of Encapsulating the DHA/VHF Photo-Switch in Cucurbiturils. Chemistry 2017; 23:17010-17016. [PMID: 28922509 DOI: 10.1002/chem.201703196] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Indexed: 11/05/2022]
Abstract
Confinement of reactive chemical species uniquely affects chemical reactivity by restricting the physical space available and by restricting access to interactions with the solvent. In Nature, for example, confined protein binding pockets govern processes following photoisomerization reactions and the isomerizations themselves. Here we describe the first example of a dihydroazulene/vinylheptafulvene (DHA/VHF) photo-switch functioning in water, and we show how its switching behavior is strongly influenced by supramolecular interactions with a series of cucurbit[n]uril (CB) host molecules. In CB7 inclusion complexes, the kinetics of the thermal VHF-to-DHA back-reaction is accelerated, while in CB8 inclusion complexes, the kinetics is slowed down as compared to the free photo-switch. The effect of the CB encapsulation of the photo-switch can be effectively canceled by introducing a guest that binds the CB more strongly. According to DFT calculations, a stabilization of the reactive s-cis VHF conformer relative to the s-trans VHF appears to be a contributing factor responsible for the accelerated back-reaction when encapsulated in CB7.
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Affiliation(s)
- Michael Å Petersen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen Ø, Denmark
| | - Brian Rasmussen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen Ø, Denmark
| | - Nicolaj N Andersen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen Ø, Denmark
| | - Stephan P A Sauer
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen Ø, Denmark
| | - Mogens Brøndsted Nielsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen Ø, Denmark
| | - Sophie R Beeren
- Department of Chemistry, Technical University of Denmark, Kemitorvet, bygning 207, 2800 Kgs., Lyngby, Denmark
| | - Michael Pittelkow
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen Ø, Denmark
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15
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Mendes AC, Shekarforoush E, Engwer C, Beeren SR, Gorzelanny C, Goycoolea FM, Chronakis IS. Co-assembly of chitosan and phospholipids into hybrid hydrogels. PURE APPL CHEM 2016. [DOI: 10.1515/pac-2016-0708] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
AbstractNovel hybrid hydrogels were formed by adding chitosan (Ch) to phospholipids (P) self-assembled particles in lactic acid. The effect of the phospholipid concentration on the hydrogel properties was investigated and was observed to affect the rate of hydrogel formation and viscoelastic properties. A lower concentration of phospholipids (0.5% wt/v) in the mixture, facilitates faster network formation as observed by Dynamic Light Scattering, with lower elastic modulus than the hydrogels formed with higher phospholipid content. The nano-porous structure of Ch/P hydrogels, with a diameter of 260±20 nm, as observed by cryo-scanning electron microscopy, facilitated the penetration of water and swelling. Cell studies revealed suitable biocompatibility of the Ch/P hydrogels that can be used within life sciences applications.
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Affiliation(s)
- Ana C. Mendes
- 1Nano-BioScience Research Group, DTU-Food, Technical University of Denmark, Søltofts plads 227, 2800 Kgs. Lyngby, Denmark
| | - Elhamalsadat Shekarforoush
- 1Nano-BioScience Research Group, DTU-Food, Technical University of Denmark, Søltofts plads 227, 2800 Kgs. Lyngby, Denmark
| | - Christoph Engwer
- 2Institute for Biology and Biotechnology of Plants (IBBP), Westfälische Wilhelms-Universität Münster, Schlossgarten 3, 48149 Münster, Germany
| | - Sophie R. Beeren
- 3DTU-Chemistry, Technical University of Denmark, Kemitorvet 207, 2800 Kgs. Lyngby, Denmark
| | - Christian Gorzelanny
- 4Experimental Dermatology, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Francisco M. Goycoolea
- 2Institute for Biology and Biotechnology of Plants (IBBP), Westfälische Wilhelms-Universität Münster, Schlossgarten 3, 48149 Münster, Germany
| | - Ioannis S. Chronakis
- 1Nano-BioScience Research Group, DTU-Food, Technical University of Denmark, Søltofts plads 227, 2800 Kgs. Lyngby, Denmark
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Cuesta-Seijo JA, Nielsen MM, Ruzanski C, Krucewicz K, Beeren SR, Rydhal MG, Yoshimura Y, Striebeck A, Motawia MS, Willats WGT, Palcic MM. In vitro Biochemical Characterization of All Barley Endosperm Starch Synthases. Front Plant Sci 2016; 6:1265. [PMID: 26858729 PMCID: PMC4730117 DOI: 10.3389/fpls.2015.01265] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/27/2015] [Indexed: 05/18/2023]
Abstract
Starch is the main storage polysaccharide in cereals and the major source of calories in the human diet. It is synthesized by a panel of enzymes including five classes of starch synthases (SSs). While the overall starch synthase (SS) reaction is known, the functional differences between the five SS classes are poorly understood. Much of our knowledge comes from analyzing mutant plants with altered SS activities, but the resulting data are often difficult to interpret as a result of pleitropic effects, competition between enzymes, overlaps in enzyme activity and disruption of multi-enzyme complexes. Here we provide a detailed biochemical study of the activity of all five classes of SSs in barley endosperm. Each enzyme was produced recombinantly in E. coli and the properties and modes of action in vitro were studied in isolation from other SSs and other substrate modifying activities. Our results define the mode of action of each SS class in unprecedented detail; we analyze their substrate selection, temperature dependence and stability, substrate affinity and temporal abundance during barley development. Our results are at variance with some generally accepted ideas about starch biosynthesis and might lead to the reinterpretation of results obtained in planta. In particular, they indicate that granule bound SS is capable of processive action even in the absence of a starch matrix, that SSI has no elongation limit, and that SSIV, believed to be critical for the initiation of starch granules, has maltoligosaccharides and not polysaccharides as its preferred substrates.
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Affiliation(s)
| | | | | | | | | | - Maja G. Rydhal
- Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Copenhagen, Denmark
| | | | | | - Mohammed S. Motawia
- Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Copenhagen, Denmark
| | - William G. T. Willats
- Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Copenhagen, Denmark
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Beeren SR, Christensen CE, Tanaka H, Jensen MG, Donaldson I, Hindsgaul O. Direct study of fluorescently-labelled barley β-glucan fate in an in vitro human colon digestion model. Carbohydr Polym 2015; 115:88-92. [DOI: 10.1016/j.carbpol.2014.08.056] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Revised: 08/05/2014] [Accepted: 08/10/2014] [Indexed: 12/20/2022]
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18
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Beeren SR, Meier S. Supramolecular chemical shift reagents inducing conformational transitions: NMR analysis of carbohydrate homooligomer mixtures. Chem Commun (Camb) 2015; 51:3073-6. [DOI: 10.1039/c4cc09710f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Supramolecular chemical shift reagents improve signal resolution for NMR analysis of homooligosaccharides by inducing conformational transitions upon binding.
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Affiliation(s)
| | - Sebastian Meier
- Technical University of Denmark
- Department of Chemistry
- Kgs. Lyngby
- Denmark
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19
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Mikkelsen MS, Cornali SB, Jensen MG, Nilsson M, Beeren SR, Meier S. Probing interactions between β-glucan and bile salts at atomic detail by ¹H-¹³C NMR assays. J Agric Food Chem 2014; 62:11472-11478. [PMID: 25375023 DOI: 10.1021/jf504352w] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Polysaccharides are prospective hosts for the delivery and sequestration of bioactive guest molecules. Polysaccharides of dietary fiber, specifically cereal (1 → 3)(1 → 4)-β-glucans, play a role in lowering the blood plasma cholesterol level in humans. Direct host-guest interactions between β-glucans and conjugated bile salts are among the possible molecular mechanisms explaining the hypocholesterolemic effects of β-glucans. The present study shows that (1)H-(13)C NMR assays on a time scale of minutes detect minute signal changes in both bile salts and β-glucans, thus indicating dynamic interactions between bile salts and β-glucans. Experiments are consistent with stronger interactions at pH 5.3 than at pH 6.5 in this in vitro assay. The changes in bile salt and β-glucan signals suggest a stabilization of bile salt micelles and concomitant conformational changes in β-glucans.
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Affiliation(s)
- Mette Skau Mikkelsen
- Faculty of Science, Department of Food Science, University of Copenhagen , Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
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20
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Affiliation(s)
- Sebastian Meier
- Department
of Chemistry, Technical University of Denmark, Kemitorvet, Building
201, Kgs Lyngby 2800, Denmark
- Carlsberg Laboratory, Gamle Carlsberg
Vej 10, Copenhagen V 1799, Denmark
| | - Sophie R. Beeren
- Carlsberg Laboratory, Gamle Carlsberg
Vej 10, Copenhagen V 1799, Denmark
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21
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Sim L, Beeren SR, Findinier J, Dauvillée D, Ball SG, Henriksen A, Palcic MM. Crystal structure of the Chlamydomonas starch debranching enzyme isoamylase ISA1 reveals insights into the mechanism of branch trimming and complex assembly. J Biol Chem 2014; 289:22991-23003. [PMID: 24993830 DOI: 10.1074/jbc.m114.565044] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The starch debranching enzymes isoamylase 1 and 2 (ISA1 and ISA2) are known to exist in a large complex and are involved in the biosynthesis and crystallization of starch. It is suggested that the function of the complex is to remove misplaced branches of growing amylopectin molecules, which would otherwise prevent the association and crystallization of adjacent linear chains. Here, we investigate the function of ISA1 and ISA2 from starch producing alga Chlamydomonas. Through complementation studies, we confirm that the STA8 locus encodes for ISA2 and sta8 mutants lack the ISA1·ISA2 heteromeric complex. However, mutants retain a functional dimeric ISA1 that is able to partly sustain starch synthesis in vivo. To better characterize ISA1, we have overexpressed and purified ISA1 from Chlamydomonas reinhardtii (CrISA1) and solved the crystal structure to 2.3 Å and in complex with maltoheptaose to 2.4 Å. Analysis of the homodimeric CrISA1 structure reveals a unique elongated structure with monomers connected end-to-end. The crystal complex reveals details about the mechanism of branch binding that explains the low activity of CrISA1 toward tightly spaced branches and reveals the presence of additional secondary surface carbohydrate binding sites.
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Affiliation(s)
- Lyann Sim
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799 Copenhagen V, Denmark and.
| | - Sophie R Beeren
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799 Copenhagen V, Denmark and
| | - Justin Findinier
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 CNRS-USTL, Bâtiment C9, Cité Scientifique, F-59655 Villeneuve d'Ascq, France
| | - David Dauvillée
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 CNRS-USTL, Bâtiment C9, Cité Scientifique, F-59655 Villeneuve d'Ascq, France
| | - Steven G Ball
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 CNRS-USTL, Bâtiment C9, Cité Scientifique, F-59655 Villeneuve d'Ascq, France
| | - Anette Henriksen
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799 Copenhagen V, Denmark and
| | - Monica M Palcic
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799 Copenhagen V, Denmark and
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Abstract
Regions of consecutive α(1–4)-glucopyranose units in amylopectin are detected by turn-on fluorescence by extraction of amphiphilic probes from fluorescence-quenched spermidine-stabilised micelles.
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23
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Beeren SR, Petersen BO, Bøjstrup M, Hindsgaul O, Meier S. Time-Resolved in-Situ Observation of Starch Polysaccharide Degradation Pathways. Chembiochem 2013; 14:2506-11. [DOI: 10.1002/cbic.201300461] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Indexed: 12/22/2022]
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25
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Beeren SR, Hindsgaul O. Nature’s Dendrimer: Characterizing Amylopectin as a Multivalent Host. Angew Chem Int Ed Engl 2013; 52:11265-8. [DOI: 10.1002/anie.201305132] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Indexed: 12/17/2022]
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26
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Bøjstrup M, Petersen BO, Beeren SR, Hindsgaul O, Meier S. Fast and Accurate Quantitation of Glucans in Complex Mixtures by Optimized Heteronuclear NMR Spectroscopy. Anal Chem 2013; 85:8802-8. [DOI: 10.1021/ac401980m] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marie Bøjstrup
- Carlsberg Laboratory, Gamle
Carlsberg Vej 10, 1799 Copenhagen V, Denmark
| | - Bent O. Petersen
- Carlsberg Laboratory, Gamle
Carlsberg Vej 10, 1799 Copenhagen V, Denmark
| | - Sophie R. Beeren
- Carlsberg Laboratory, Gamle
Carlsberg Vej 10, 1799 Copenhagen V, Denmark
| | - Ole Hindsgaul
- Carlsberg Laboratory, Gamle
Carlsberg Vej 10, 1799 Copenhagen V, Denmark
| | - Sebastian Meier
- Carlsberg Laboratory, Gamle
Carlsberg Vej 10, 1799 Copenhagen V, Denmark
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Cuesta-Seijo JA, Nielsen MM, Marri L, Tanaka H, Beeren SR, Palcic MM. Structure of starch synthase I from barley: insight into regulatory mechanisms of starch synthase activity. Acta Crystallogr D Biol Crystallogr 2013; 69:1013-25. [DOI: 10.1107/s090744491300440x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 02/14/2013] [Indexed: 11/11/2022]
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Petersen BO, Olsen O, Beeren SR, Hindsgaul O, Meier S. Monitoring pathways of β-glucan degradation by enzyme mixtures in situ. Carbohydr Res 2013; 368:47-51. [DOI: 10.1016/j.carres.2012.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Accepted: 12/07/2012] [Indexed: 11/15/2022]
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29
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Johannesen SA, Beeren SR, Blank D, Yang BY, Geyer R, Hindsgaul O. Glycan analysis via derivatization with a fluorogenic pyrylium dye. Carbohydr Res 2012; 352:94-100. [DOI: 10.1016/j.carres.2012.02.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 02/13/2012] [Accepted: 02/15/2012] [Indexed: 10/28/2022]
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30
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Beeren SR, Pittelkow M, Sanders JKM. From static to dynamic: escaping kinetic traps in hydrazone-based dynamic combinatorial libraries. Chem Commun (Camb) 2011; 47:7359-61. [PMID: 21643569 DOI: 10.1039/c1cc12268a] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thermodynamic control over kinetically-trapped mixtures of hydrazone-based macrocycles is achieved by addition of an aromatic monohydrazide to generate dynamic combinatorial libraries (DCLs) of linear and macrocyclic oligomers.
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Affiliation(s)
- Sophie R Beeren
- University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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31
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Beeren SR, Sanders JKM. Discovery of linear receptors for multiple dihydrogen phosphate ions using dynamic combinatorial chemistry. J Am Chem Soc 2011; 133:3804-7. [PMID: 21361379 DOI: 10.1021/ja200130h] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We describe the use of dynamic combinatorial chemistry to discover a new series of linear hydrazone-based receptors that bind multiple dihydrogen phosphate ions. Through the use of a template-driven, selection-based approach to receptor synthesis, dynamic combinatorial chemistry allows for the identification of unexpected host structures and binding motifs. Notably, we observed the unprecedented selection of these linear receptors in preference to competing macrocyclic hosts. Furthermore, linear receptors containing up to nine building blocks and three different building blocks were amplified in the dynamic combinatorial library. The receptors were formed using a dihydrazide building block based on an amino acid-disubstituted ferrocene scaffold. A detailed study of the linear pentamer revealed that it forms a helical ditopic receptor that employs four acylhydrazone hydrogen-bond donor motifs to cooperatively bind two dihydrogen phosphate ions.
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Affiliation(s)
- Sophie R Beeren
- University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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33
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Beeren SR, Dabb SL, Edwards G, Smith MK, Willis AC, Messerle BA. Improving intramolecular hydroamination Rh(i) and Ir(i) catalysts through targeted ligand modification. NEW J CHEM 2010. [DOI: 10.1039/b9nj00759h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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