1
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O'Neill NS, Alvarez NJ, Schweitzer-Stenner R. Tuning the thermostability of GHG gels by salts at different positions on the Hofmeister scale. Sci Rep 2024; 14:14742. [PMID: 38926473 PMCID: PMC11208536 DOI: 10.1038/s41598-024-65145-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 06/17/2024] [Indexed: 06/28/2024] Open
Abstract
The influence of Hofmeister cations (NH4+, Na+, Mg2+) and anions (H2PO4-, CH3COO-, Cl-, NO3-) on the thermostability of a GHG hydrogel was investigated. The combined results of UV circular dichroism (UVCD) and Small Amplitude Oscillatory Shear Rheology experiments reveal that the addition of salt reduces the stability of the gel phase and the underlying fibrils. In line with the cationic Hofmeister hierarchy, the chaotropic Mg2+ ions caused the greatest thermal destabilization of the gel phase with the gel → sol transition temperature Tgs value lowered by 10 °C. In the absence of salt, the gel → sol transition probed by the storage modulus and microscopy is biphasic. In the presence of salt, it becomes monophasic. Contrary to expectations the presence of Hofmeister anions leads to a nearly identical reduction of the gel → sol transition temperatures. However, UVCD spectra suggest that they affect the ππ-stacking between imidazole groups to a different extent. We relate the absence of ion specificity regarding the solubility of fibrils (probed by UVCD) to the observed enthalpy-entropy compensation of the dissolution process. Our results combined show how CD spectroscopy and rheology combined yields a more nuanced picture of the processes underlying the gel → sol transition.
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Affiliation(s)
- Nichole S O'Neill
- Department of Chemistry, Drexel University, Philadelphia, PA, 19104, USA
| | - Nicolas J Alvarez
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA, 19104, USA.
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2
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Li M, Li X, Lv Y, Yan H, Wang XY, He J, Zhou C, Ouyang Y. Chiral MoS 2@BC fibrous membranes selectively promote peripheral nerve regeneration. J Nanobiotechnology 2024; 22:337. [PMID: 38886712 PMCID: PMC11181549 DOI: 10.1186/s12951-024-02493-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 04/22/2024] [Indexed: 06/20/2024] Open
Abstract
BACKGROUND Molybdenum disulfide (MoS2) has excellent physical and chemical properties. Further, chiral MoS2 (CMS) exhibits excellent chiroptical and enantioselective effects, and the enantioselective properties of CMS have been studied for the treatment of neurodegenerative diseases. Intriguingly, left- and right-handed materials have different effects on promoting the differentiation of neural stem cells into neurons. However, the effect of the enantioselectivity of chiral materials on peripheral nerve regeneration remains unclear. METHODS In this study, CMS@bacterial cellulose (BC) scaffolds were fabricated using a hydrothermal approach. The CMS@BC films synthesized with L-2-amino-3-phenyl-1-propanol was defined as L-CMS. The CMS@BC films synthesized with D-2-amino-3-phenyl-1-propanol was defined as D-CMS. The biocompatibility of CMS@BC scaffolds and their effect on Schwann cells (SCs) were validated by cellular experiments. In addition, these scaffolds were implanted in rat sciatic nerve defect sites for three months. RESULTS These chiral scaffolds displayed high hydrophilicity, good mechanical properties, and low cytotoxicity. Further, we found that the L-CMS scaffolds were superior to the D-CMS scaffolds in promoting SCs proliferation. After three months, the scaffolds showed good biocompatibility in vivo, and the nerve conducting velocities of the L-CMS and D-CMS scaffolds were 51.2 m/s and 26.8 m/s, respectively. The L-CMS scaffolds showed a better regenerative effect than the D-CMS scaffolds. Similarly, the sciatic nerve function index and effects on the motor and electrophysiological functions were higher for the L-CMS scaffolds than the D-CMS scaffolds. Finally, the axon diameter and myelin sheath thickness of the regenerated nerves were improved in the L-CMS group. CONCLUSION We found that the CMS@BC can promote peripheral nerve regeneration, and in general, the L-CMS group exhibited superior repair performance. Overall, the findings of this study reveal that CMS@BC can be used as a chiral nanomaterial nerve scaffold for peripheral nerve repair.
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Affiliation(s)
- Mengru Li
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
- Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai, 201306, China
| | - Xiao Li
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Yaowei Lv
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
- Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai, 201306, China
| | - Hede Yan
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Xiang-Yang Wang
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Jin He
- Department of Pediatric Orthopaedics, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China.
| | - Chao Zhou
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.
- Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai, 201306, China.
| | - Yuanming Ouyang
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.
- Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai, 201306, China.
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3
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Szepke D, Zarzeczny M, Pawlak M, Jarmuła P, Yoshizawa A, Pociecha D, Lewandowski W. Disentangling optical effects in 3D spiral-like, chiral plasmonic assemblies templated by a dark conglomerate liquid crystal. J Chem Phys 2024; 160:074201. [PMID: 38380754 DOI: 10.1063/5.0179535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 01/22/2024] [Indexed: 02/22/2024] Open
Abstract
Chiral thin films showing electronic and plasmonic circular dichroism (CD) are intensively explored for optoelectronic applications. The most studied chiral organic films are the composites exhibiting a helical geometry, which often causes entanglement of circular optical properties with unwanted linear optical effects (linearly polarized absorption or refraction). This entanglement limits tunability and often translates to a complex optical response. This paper describes chiral films based on dark conglomerate, sponge-like, liquid crystal films, which go beyond the usual helical type geometry, waiving the problem of linear contributions to chiroptical electronic and plasmonic properties. First, we show that purely organic films exhibit high electronic CD and circular birefringence, as studied in detail using Mueller matrix polarimetry. Analogous linear properties are two orders of magnitude lower, highlighting the benefits of using the bi-isotropic dark conglomerate liquid crystal for chiroptical purposes. Next, we show that the liquid crystal can act as a template to guide the assembly of chemically compatible gold nanoparticles into 3D spiral-like assemblies. The Mueller matrix polarimetry measurements confirm that these composites exhibit both electronic and plasmonic circular dichroisms, while nanoparticle presence is not compromising the beneficial optical properties of the matrix.
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Affiliation(s)
- Dorota Szepke
- Faculty of Chemistry, University of Warsaw, Ludwika Pasteura 1, 02-093 Warsaw, Poland
| | - Mateusz Zarzeczny
- Faculty of Chemistry, University of Warsaw, Ludwika Pasteura 1, 02-093 Warsaw, Poland
| | - Mateusz Pawlak
- Faculty of Chemistry, University of Warsaw, Ludwika Pasteura 1, 02-093 Warsaw, Poland
| | - Paweł Jarmuła
- Faculty of Chemistry, University of Warsaw, Ludwika Pasteura 1, 02-093 Warsaw, Poland
| | - Atsushi Yoshizawa
- National University Corporation, Hirosaki University, 1 Bunkyo-cho, Hirosaki, Aomori 036-8560, Japan
| | - Damian Pociecha
- Faculty of Chemistry, University of Warsaw, Ludwika Pasteura 1, 02-093 Warsaw, Poland
| | - Wiktor Lewandowski
- Faculty of Chemistry, University of Warsaw, Ludwika Pasteura 1, 02-093 Warsaw, Poland
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4
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Collette D, Dunlap D, Finzi L. Macromolecular Crowding and DNA: Bridging the Gap between In Vitro and In Vivo. Int J Mol Sci 2023; 24:17502. [PMID: 38139331 PMCID: PMC10744201 DOI: 10.3390/ijms242417502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/29/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
The cellular environment is highly crowded, with up to 40% of the volume fraction of the cell occupied by various macromolecules. Most laboratory experiments take place in dilute buffer solutions; by adding various synthetic or organic macromolecules, researchers have begun to bridge the gap between in vitro and in vivo measurements. This is a review of the reported effects of macromolecular crowding on the compaction and extension of DNA, the effect of macromolecular crowding on DNA kinetics, and protein-DNA interactions. Theoretical models related to macromolecular crowding and DNA are briefly reviewed. Gaps in the literature, including the use of biologically relevant crowders, simultaneous use of multi-sized crowders, empirical connections between macromolecular crowding and liquid-liquid phase separation of nucleic materials are discussed.
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Affiliation(s)
| | | | - Laura Finzi
- Department of Physics, College of Arts & Sciences, Emory University, Atlanta, GA 30322, USA; (D.C.); (D.D.)
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5
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Duan Y, Che S. Chiral Mesostructured Inorganic Materials with Optical Chiral Response. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2205088. [PMID: 36245314 DOI: 10.1002/adma.202205088] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 09/15/2022] [Indexed: 06/16/2023]
Abstract
Fabricating chiral inorganic materials and revealing their unique quantum confinement-determined optical chiral responses are crucial tasks in the multidisciplinary fields of chemistry, physics, and biology. The field of chiral mesostructured inorganic materials started from the synthesis of individual nanocrystals and evolved to include their assembly from metals, semiconductors, ceramics, and inorganic salts endowed with various chiral structures ranging from atomic to micron scales. This tutorial review highlights the recent research on chiral mesostructured inorganic materials, especially the novel expression of mesostructured chirality and endowed optical chiral response, and it may inspire us with new strategies for the design of chiral inorganic materials and new opportunities beyond the traditional applications of chirality. Fabrication methods for chiral mesostructured inorganic materials are classified according to chirality type, scale, and symmetry-breaking mechanism. Special attention is given to highlight systems with original discoveries, exceptional phenomena, or unique mechanisms of optical chiral response for left- and right-handedness.
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Affiliation(s)
- Yingying Duan
- School of Chemical Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, P. R. China
| | - Shunai Che
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, State Key Laboratory of Matrix Composite, Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China
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6
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Samanta D, Shaw M, Shaik MAS, Basu R, Mondal I, Bhattacharya A, Pathak A. Optical Asymmetry and Structural Complexity in Hierarchically Organized Chiral CuO Nanostructures: Insight into the Geometric and Crystallographic Effects on Cooperative Chirality. Inorg Chem 2023; 62:16725-16733. [PMID: 37768369 DOI: 10.1021/acs.inorgchem.3c01861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Optical asymmetry and structural complexity across different length scales were realized in flower-shaped CuO nanostructures, prepared through refluxing an aqueous solution of copper acetate, sodium hydroxide, and D-tartaric acid, as well as in their toroid-like forms obtained on calcination at 600 °C. Atomic scale chirality in the flower morphology could be visualized as putative Boerdijk-Coexter-Bernal like tetrahelical fragments, while that in the toroid form could be identified as screw dislocation-driven helicity. The fraction of asymmetry in the nanostructures has been evaluated from their chiroptical responses based on Kuhn asymmetry factor (g) from circular dichroism (CD) spectroscopy in the entire UV-vis range. The origin of chirality in the two CuO nanostructures has been assigned to the helical arrangement of the Cu-O-Cu network in accordance with their microscopic and spectroscopic observations. Attempts have been made to interpret the crystallographic and geometric chiralities in the two CuO nanostructures based on the redshift and augmented intensity of the CD signal along with an increase in their corresponding anisotropic factor on calcination. Further, the diverse interaction of the toroid-shaped CuO nanostructures with enantiomeric tryptophan moieties has been illustrated from the measurement of their corresponding thermodynamic parameters.
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Affiliation(s)
- Dipanjan Samanta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, W.B. 721302, India
| | - Manisha Shaw
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, W.B. 721302, India
| | - Md Abdus Salam Shaik
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, W.B. 721302, India
| | - Rajarshi Basu
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, W.B. 721302, India
| | - Imran Mondal
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, W.B. 721302, India
| | - Angana Bhattacharya
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, W.B. 721302, India
| | - Amita Pathak
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, W.B. 721302, India
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7
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Morozov VN, Klimovich MA, Shibaeva AV, Klimovich ON, Koshevaya ED, Kolyvanova MA, Kuzmin VA. Optical Polymorphism of Liquid-Crystalline Dispersions of DNA at High Concentrations of Crowding Polymer. Int J Mol Sci 2023; 24:11365. [PMID: 37511123 PMCID: PMC10379083 DOI: 10.3390/ijms241411365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 07/30/2023] Open
Abstract
Optically active liquid-crystalline dispersions (LCD) of nucleic acids, obtained by polymer- and salt-induced (psi-) condensation, e.g., by mixing of aqueous saline solutions of low molecular weight DNA (≤106 Da) and polyethylene glycol (PEG), possess an outstanding circular dichroism (CD) signal (so-called psi-CD) and are of interest for sensor applications. Typically, such CD signals are observed in PEG content from ≈12.5% to ≈22%. However, in the literature, there are very conflicting data on the existence of psi-CD in DNA LCDs at a higher content of crowding polymer up to 30-40%. In the present work, we demonstrate that, in the range of PEG content in the system above ≈24%, optically polymorphic LCDs can be formed, characterized by both negative and positive psi-CD signals, as well as by ones rather slightly differing from the spectrum of isotropic DNA solution. Such a change in the CD signal is determined by the concentration of the stock solution of PEG used for the preparation of LCDs. We assume that various saturation of polymer chains with water molecules may affect the amount of active water, which in turn leads to a change in the hydration of DNA molecules and their transition from B-form to Z-form.
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Affiliation(s)
- Vladimir N Morozov
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina, 119334 Moscow, Russia
| | - Mikhail A Klimovich
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina, 119334 Moscow, Russia
- Burnazyan Federal Medical Biophysical Center, Federal Medical Biological Agency of the Russian Federation, 23 Marshala Novikova, 123182 Moscow, Russia
| | - Anna V Shibaeva
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina, 119334 Moscow, Russia
| | - Olga N Klimovich
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina, 119334 Moscow, Russia
| | - Ekaterina D Koshevaya
- Burnazyan Federal Medical Biophysical Center, Federal Medical Biological Agency of the Russian Federation, 23 Marshala Novikova, 123182 Moscow, Russia
| | - Maria A Kolyvanova
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina, 119334 Moscow, Russia
- Burnazyan Federal Medical Biophysical Center, Federal Medical Biological Agency of the Russian Federation, 23 Marshala Novikova, 123182 Moscow, Russia
| | - Vladimir A Kuzmin
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina, 119334 Moscow, Russia
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8
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Massa M, Rivara M, Pertinhez TA, Compari C, Donofrio G, Cristofolini L, Orsi D, Franceschi V, Fisicaro E. Chemico-Physical Properties of Some 1,1'-Bis-alkyl-2,2'-hexane-1,6-diyl-bispyridinium Chlorides Hydrogenated and Partially Fluorinated for Gene Delivery. Molecules 2023; 28:molecules28083585. [PMID: 37110819 PMCID: PMC10145364 DOI: 10.3390/molecules28083585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023] Open
Abstract
The development of very efficient and safe non-viral vectors, constituted mainly by cationic lipids bearing multiple charges, is a landmark for in vivo gene-based medicine. To understand the effect of the hydrophobic chain's length, we here report the synthesis, and the chemico-physical and biological characterization, of a new term of the homologous series of hydrogenated gemini bispyridinium surfactants, the 1,1'-bis-dodecyl-2,2'-hexane-1,6-diyl-bispyridinium chloride (GP12_6). Moreover, we have collected and compared the thermodynamic micellization parameters (cmc, changes in enthalpy, free energy, and entropy of micellization) obtained by isothermal titration calorimetry (ITC) experiments for hydrogenated surfactants GP12_6 and GP16_6, and for the partially fluorinated ones, FGPn (where n is the spacer length). The data obtained for GP12_6 by EMSA, MTT, transient transfection assays, and AFM imaging show that in this class of compounds, the gene delivery ability strictly depends on the spacer length but barely on the hydrophobic tail length. CD spectra have been shown to be a useful tool to verify the formation of lipoplexes due to the presence of a "tail" in the 288-320 nm region attributed to a chiroptical feature named ψ-phase. Ellipsometric measurements suggest that FGP6 and FGP8 (showing a very interesting gene delivery activity, when formulated with DOPE) act in a very similar way, and dissimilar from FGP4, exactly as in the case of transfection, and confirm the hypothesis suggested by previously obtained thermodynamic data about the requirement of a proper length of the spacer to allow the molecule to form a sort of molecular tong able to intercalate DNA.
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Affiliation(s)
- Michele Massa
- Department of Maternal Infantile and Urological Sciences, Sapienza University of Rome, 00165 Rome, Italy
| | - Mirko Rivara
- Department Food and Drug, University of Parma, Parco Area delle Scienze, 27/A, 43124 Parma, Italy
| | - Thelma A Pertinhez
- Department of Medicine and Surgery, University of Parma, Via Volturno, 39, 43125 Parma, Italy
| | - Carlotta Compari
- Department Food and Drug, University of Parma, Parco Area delle Scienze, 27/A, 43124 Parma, Italy
| | - Gaetano Donofrio
- Department of Veterinary Sciences, University of Parma, Via del Taglio, 10, 43126 Parma, Italy
| | - Luigi Cristofolini
- Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/a, 43124 Parma, Italy
| | - Davide Orsi
- Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/a, 43124 Parma, Italy
| | - Valentina Franceschi
- Department of Veterinary Sciences, University of Parma, Via del Taglio, 10, 43126 Parma, Italy
| | - Emilia Fisicaro
- Department Food and Drug, University of Parma, Parco Area delle Scienze, 27/A, 43124 Parma, Italy
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9
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Synchronous quantitative analysis of chiral mesostructured inorganic crystals by 3D electron diffraction tomography. Nat Commun 2022; 13:5718. [PMID: 36175426 PMCID: PMC9522932 DOI: 10.1038/s41467-022-33443-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/19/2022] [Indexed: 11/08/2022] Open
Abstract
Chiral mesostructures exhibit distinctive twisting and helical hierarchical stacking ranging from atomic to micrometre scales with fascinating structural-chiral anisotropy properties. However, the detailed determination of their multilevel chirality remains challenging due to the limited information from spectroscopy, diffraction techniques, scanning electron microscopy and the two-dimensional projections in transmission electron microscopy. Herein, we report a general approach to determine chiral hierarchical mesostructures based on three-dimensional electron diffraction tomography (3D EDT), by which the structure can be solved synchronously according to the quantitative measurement of diffraction spot deformations and their arrangement in reciprocal space. This method was verified on two samples-chiral mesostructured nickel molybdate and chiral mesostructured tin dioxide-revealing hierarchical chiral structures that cannot be determined by conventional techniques. This approach provides more precise and comprehensive identification of the hierarchical mesostructures, which is expected to advance our understanding of structural-chiral anisotropy at the fundamental level.
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10
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Patty CL, Pommerol A, Kühn JG, Demory BO, Thomas N. Directional Aspects of Vegetation Linear and Circular Polarization Biosignatures. ASTROBIOLOGY 2022; 22:1034-1046. [PMID: 35984943 PMCID: PMC9508456 DOI: 10.1089/ast.2021.0156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 03/12/2022] [Indexed: 06/15/2023]
Abstract
Homochirality is a generic and unique property of all biochemical life and it is considered a universal and agnostic biosignature. Upon interaction with unpolarized light, homochirality induces fractional circular polarization in the light that is scattered from it, which can be sensed remotely. As such, it can be a prime candidate biosignature in the context of future life detection missions and observatories. The linear polarizance of vegetation is also sometimes envisaged as a biosignature, although it does not share the same molecular origin as circular polarization. It is known that linear polarization of surfaces is strongly dependent on the phase angle. The relationship between the phase angle and circular polarization stemming from macromolecular assemblies such as in vegetation, however, remained unclear. In this study, using the average of 27 different species, we demonstrate that the circular polarization-phase angle dependency of vegetation induces relatively small changes in spectral shape and mostly affects the signal magnitude. With these results, we underline the use of circular spectropolarimetry as a promising agnostic biosignature complementary to the use of linear spectropolarimetry and scalar reflectance.
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Affiliation(s)
- C.H. Lucas Patty
- Weltraumforschung und Planetologie (WP), Physikalisches Institut and Universität Bern, Bern, Switzerland
| | - Antoine Pommerol
- Weltraumforschung und Planetologie (WP), Physikalisches Institut and Universität Bern, Bern, Switzerland
| | - Jonas G. Kühn
- Center for Space and Habitability, Universität Bern, Bern, Switzerland
- Département d'Astronomie, Université de Genève, Versoix, Switzerland
| | | | - Nicolas Thomas
- Weltraumforschung und Planetologie (WP), Physikalisches Institut and Universität Bern, Bern, Switzerland
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11
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Taketomi Y, Yamaguchi Y, Sakurai S, Tanaka M. Evaluation of DNA-mediated electron transfer using a hole-trapping nucleobase under crowded conditions. Org Biomol Chem 2022; 20:2043-2047. [PMID: 35005766 DOI: 10.1039/d1ob01669e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of a crowded environment on DNA-mediated electron transfer were evaluated using a pyrene-modified oligonucleotide containing a hole-trapping nucleobase in poly(ethylene glycol) mixed solutions. Rapid decompositions of hole-trapping bases in condensed and noncondensed DNA showed that more efficient electron transfer occurred under crowded conditions than in dilute solutions.
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Affiliation(s)
- Yuuki Taketomi
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan.
| | - Yuuki Yamaguchi
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan.
| | - Shunsuke Sakurai
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan.
| | - Makiko Tanaka
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan.
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12
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Yadav MR, Kumar M, Murumkar PR. Further Studies on Cationic Gemini Amphiphiles as Carriers for Gene Delivery-The Effect of Linkers in the Structure and Other Factors Affecting the Transfection Efficacy of These Amphiphiles. ACS OMEGA 2021; 6:33370-33388. [PMID: 34926887 PMCID: PMC8674915 DOI: 10.1021/acsomega.1c03667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 09/30/2021] [Indexed: 06/14/2023]
Abstract
Gene therapy has the therapeutic potential to address a multitude of health problems, and it also has utility in different domains of science. However, its applications are plagued due to the absence of a suitable, safe, efficient, selective, and universal vector, which could help in delivering the desired nucleic acid cargo to the site of action. Though viral vectors are efficient, they pose various health risks. Different types of synthetic agents have been tried as nucleic acid vectors by researchers but with limited success. Gemini amphiphiles (GAs) are a class of synthetic surfactants having biscationic heads with attached hydrophilic and lipophilic groups. Herein, we synthesized two classes of GAs differing in the chemical nature and length of the linkers, head groups, and lipophilic chains. The resulting compounds were evaluated for their efficiency to transfect A549 and HeLa cell lines with a β-galactosidase reporter plasmid. A 3-oxypentyl linker, a monohydroxyethyl head group, and a tetradecyl moiety as the lipophilic chain offered the best transfection efficiency (compound 10BIII). Dioleoylphosphatidylethanolamine (DOPE) as the helper lipid improved the transfection efficacy of the GAs in the absence of serum. In the presence of serum, DOPE and cholesterol, as the helper lipids, improved the transfection efficacy of the resulting formulations. The synthesized GAs showed concentration-dependent toxicity in the MTT assay. Biodistribution studies using 99mTc-labeled lipoplexes indicated that the lipoplexes got concentrated in some vital organs such as the spleen, liver, and lungs.
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Affiliation(s)
- Mange Ram Yadav
- Faculty
of Pharmacy, The Maharaja Sayajirao University
of Baroda, Vadodara 390 001, Gujarat, India
- Centre
of Research for Development, Parul University, Waghodia Road, Vadodara 391 760, Gujarat, India
| | - Mukesh Kumar
- Faculty
of Pharmacy, The Maharaja Sayajirao University
of Baroda, Vadodara 390 001, Gujarat, India
| | - Prashant R. Murumkar
- Faculty
of Pharmacy, The Maharaja Sayajirao University
of Baroda, Vadodara 390 001, Gujarat, India
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13
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Meskers SCJ. Circular Polarization of Luminescence as a Tool To Study Molecular Dynamical Processes. CHEMPHOTOCHEM 2021. [DOI: 10.1002/cptc.202100154] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Stefan C. J. Meskers
- Molecular Materials and Nanosystems and Institute for Complex Molecular Systems Eindhoven University of Technology P.O. box 513 (STW 4.37) NL 5600 MB Eindhoven Netherlands
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14
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Differential Polarization Imaging of Plant Cells. Mapping the Anisotropy of Cell Walls and Chloroplasts. Int J Mol Sci 2021; 22:ijms22147661. [PMID: 34299279 PMCID: PMC8306740 DOI: 10.3390/ijms22147661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 11/17/2022] Open
Abstract
Modern light microscopy imaging techniques have substantially advanced our knowledge about the ultrastructure of plant cells and their organelles. Laser-scanning microscopy and digital light microscopy imaging techniques, in general—in addition to their high sensitivity, fast data acquisition, and great versatility of 2D–4D image analyses—also opened the technical possibilities to combine microscopy imaging with spectroscopic measurements. In this review, we focus our attention on differential polarization (DP) imaging techniques and on their applications on plant cell walls and chloroplasts, and show how these techniques provided unique and quantitative information on the anisotropic molecular organization of plant cell constituents: (i) We briefly describe how laser-scanning microscopes (LSMs) and the enhanced-resolution Re-scan Confocal Microscope (RCM of Confocal.nl Ltd. Amsterdam, Netherlands) can be equipped with DP attachments—making them capable of measuring different polarization spectroscopy parameters, parallel with the ‘conventional’ intensity imaging. (ii) We show examples of different faces of the strong anisotropic molecular organization of chloroplast thylakoid membranes. (iii) We illustrate the use of DP imaging of cell walls from a variety of wood samples and demonstrate the use of quantitative analysis. (iv) Finally, we outline the perspectives of further technical developments of micro-spectropolarimetry imaging and its use in plant cell studies.
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15
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Sparks WB, Parenteau MN, Blankenship RE, Germer TA, Patty CHL, Bott KM, Telesco CM, Meadows VS. Spectropolarimetry of Primitive Phototrophs as Global Surface Biosignatures. ASTROBIOLOGY 2021; 21:219-234. [PMID: 33216615 PMCID: PMC7876348 DOI: 10.1089/ast.2020.2272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 10/12/2020] [Indexed: 06/11/2023]
Abstract
Photosynthesis is an ancient metabolic process that began on early Earth and offers plentiful energy to organisms that can utilize it such that that they achieve global significance. The potential exists for similar processes to operate on habitable exoplanets and result in observable biosignatures. Before the advent of oxygenic photosynthesis, the most primitive phototrophs, anoxygenic phototrophs, dominated surface environments on the planet. Here, we characterize surface polarization biosignatures associated with a diverse sample of anoxygenic phototrophs and cyanobacteria, examining both pure cultures and microbial communities from the natural environment. Polarimetry is a tool that can be used to measure the chiral signature of biomolecules. Chirality is considered a universal, agnostic biosignature that is independent of a planet's biochemistry, receiving considerable interest as a target biosignature for life-detection missions. In contrast to preliminary indications from earlier work, we show that there is a diversity of distinctive circular polarization signatures, including the magnitude of the polarization, associated with the variety of chiral photosynthetic pigments and pigment complexes of anoxygenic and oxygenic phototrophs. We also show that the apparent death and release of pigments from one of the phototrophs is accompanied by an elevation of the reflectance polarization signal by an order of magnitude, which may be significant for remotely detectable environmental signatures. This work and others suggest that circular polarization signals up to ∼1% may occur, significantly stronger than previously anticipated circular polarization levels. We conclude that global surface polarization biosignatures may arise from anoxygenic and oxygenic phototrophs, which have dominated nearly 80% of the history of our rocky, inhabited planet.
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Affiliation(s)
- William B. Sparks
- SETI Institute, Mountain View, California, USA
- Space Telescope Science Institute, Baltimore, Maryland, USA
| | - Mary Niki Parenteau
- Virtual Planetary Laboratory, University of Washington, Seattle, Washington, USA
- NASA Ames Research Center, Moffett Field, California, USA
| | - Robert E. Blankenship
- Virtual Planetary Laboratory, University of Washington, Seattle, Washington, USA
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Thomas A. Germer
- National Institute of Standards and Technology, Gaithersburg, Maryland, USA
| | - Christian Herman Lucas Patty
- Institute of Plant Biology, Hungarian Academy of Sciences, Szeged, Hungary
- Space Research and Planetary Sciences, University of Bern, Bern, Switzerland
| | - Kimberly M. Bott
- Virtual Planetary Laboratory, University of Washington, Seattle, Washington, USA
- Department of Earth and Planetary Sciences, University of California, Riverside, Riverside, California, USA
| | - Charles M. Telesco
- Department of Astronomy, University of Florida, Gainesville, Florida, USA
| | - Victoria S. Meadows
- Virtual Planetary Laboratory, University of Washington, Seattle, Washington, USA
- Department of Astronomy, University of Washington, Seattle, Washington, USA
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16
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Kjær C, Jones NC, Stockett MH, Hoffmann SV, Nielsen SB. Circular dichroism, anisotropy and absorption spectroscopy of chlorophyll b in methanol and mixed methanol-water solutions. Phys Chem Chem Phys 2020; 22:26961-26966. [PMID: 33206737 DOI: 10.1039/d0cp03284k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The spectroscopic properties of chlorophyll (Chl) strongly depend on interactions with other Chl molecules, a fact that nature exploits in light harvesting by photosynthetic proteins. In solution, complex Chl aggregates are formed that depend not only on the solvent, but also on the detailed preparation procedure. Here we report synchrotron radiation circular dichroism (SRCD) spectra of Chlb in methanol (MeOH) and MeOH/H2O mixtures; in the latter, water molecules assist in the formation of Chl aggregates as Chlb is too hydrophobic to dissolve in water. The magnitude of the most prominent CD signal increases up to 100-fold over time (2-15 hours) when the water content is increased from 0 to 50% in volume, the signal is non-conservative (almost exclusively negative), and sensitive to sample preparation. Three different types of signature CD spectra (Types A to C) are identified depending on preparation, and the change in CD signal over time and with temperature is further analyzed with anisotropy spectroscopy (ratio of simultaneously recorded CD to absorption) and principal component analysis (PCA). We show that CD is clearly superior to pure absorption spectroscopy in identifying structural changes, and anisotropy spectroscopy further increases the sensitivity towards smaller structural changes. PCA on temperature dependent CD data show that depending on preparation, and thus the type of aggregate as revealed by the CD signature, either one (Type A) or two chiral species (Type B) are identified in the spectra, further evidencing the complex nature of Chlb aggregates. Furthermore, the CD signal decreases linearly with volume when a sample of Chlb in MeOH/H2O (i.e., a sample of Chlb aggregates) is diluted, which implies that the aggregation process is irreversible: once aggregates are formed, they largely do not revert back to monomers. However, anisotropy spectroscopy reveals that there are small changes in the aggregates, not directly noticeable in CD and absorption. The work presented here demonstrates, compared to absorption spectroscopy, a clear advantage of CD and anisotropy spectroscopy in studying the complex evolution of Chl samples with time and temperature.
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Affiliation(s)
- Christina Kjær
- Department of Physics and Astronomy, Aarhus University, Denmark.
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17
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Circular Intensity Differential Scattering for Label-Free Chromatin Characterization: A Review for Optical Microscopy. Polymers (Basel) 2020; 12:polym12102428. [PMID: 33096877 PMCID: PMC7588990 DOI: 10.3390/polym12102428] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/09/2020] [Accepted: 10/16/2020] [Indexed: 02/08/2023] Open
Abstract
Circular Intensity Differential Scattering (CIDS) provides a differential measurement of the circular right and left polarized light and has been proven to be a gold standard label-free technique to study the molecular conformation of complex biopolymers, such as chromatin. In early works, it has been shown that the scattering component of the CIDS signal gives information from the long-range chiral organization on a scale down to 1/10th-1/20th of the excitation wavelength, leading to information related to the structure and orientation of biopolymers in situ at the nanoscale. In this paper, we review the typical methods and technologies employed for measuring this signal coming from complex macro-molecules ordering. Additionally, we include a general description of the experimental architectures employed for spectroscopic CIDS measurements, angular or spectral, and of the most recent advances in the field of optical imaging microscopy, allowing a visualization of the chromatin organization in situ.
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18
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Improved Production and Biophysical Analysis of Recombinant Silicatein-α. Biomolecules 2020; 10:biom10091209. [PMID: 32825281 PMCID: PMC7565869 DOI: 10.3390/biom10091209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/12/2020] [Accepted: 08/17/2020] [Indexed: 11/16/2022] Open
Abstract
Silicatein-α is a hydrolase found in siliceous sea sponges with a unique ability to condense and hydrolyse silicon–oxygen bonds. The enzyme is thus of interest from the perspective of its unusual enzymology, and for potential applications in the sustainable synthesis of siloxane-containing compounds. However, research into this enzyme has previously been hindered by the tendency of silicatein-α towards aggregation and insolubility. Herein, we report the development of an improved method for the production of a trigger factor-silicatein fusion protein by switching the previous hexahistidine tag for a Strep-II tag, resulting in 244-fold improvement in protein yield compared to previous methods. Light scattering and thermal denaturation analyses show that under the best storage conditions, although oligomerisation is never entirely abolished, these nanoscale aggregates of the Strep-tagged protein exhibit improved colloidal stability and solubility. Enzymatic assays show that the Strep-tagged protein retains catalytic competency, but exhibits lower activity compared to the His6-tagged protein. These results suggest that the hexahistidine tag is capable of non-specific catalysis through their imidazole side chains, highlighting the importance of careful consideration when selecting a purification tag. Overall, the Strep-tagged fusion protein reported here can be produced to a higher yield, exhibits greater stability, and allows the native catalytic properties of this protein to be assessed.
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19
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Zhao B, Yu H, Pan K, Tan Z, Deng J. Multifarious Chiral Nanoarchitectures Serving as Handed-Selective Fluorescence Filters for Generating Full-Color Circularly Polarized Luminescence. ACS NANO 2020; 14:3208-3218. [PMID: 32022541 DOI: 10.1021/acsnano.9b08618] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A series of full-color circularly polarized luminescence (CPL)-active materials are fabricated by judiciously combining multifarious chiral nanoarchitectures with achiral fluorescence dyes. The investigated nanoarchitectures include organic polymer nanofibers, organic-inorganic hybrid nanoflowers, and inorganic nanoflowers. The as-prepared chiral nanoarchitectures all can act as handed-selective fluorescence filters to powerfully transform unpolarized fluorescent light into circularly polarized luminescence. Also notable, no interaction is required between chiral and fluorescent components for achieving CPL emission. The present study provides a convenient and universal approach for preparing full-color CPL materials. Following the strategy, numerous chiroptical materials with CPL performance can be expected due to the abundant chiral matters and achiral fluorophores.
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Affiliation(s)
- Biao Zhao
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Huli Yu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Kai Pan
- College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Zhan'ao Tan
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jianping Deng
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
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20
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Krupová M, Kessler J, Bouř P. Recent Trends in Chiroptical Spectroscopy: Theory and Applications of Vibrational Circular Dichroism and Raman Optical Activity. Chempluschem 2020; 85:561-575. [DOI: 10.1002/cplu.202000014] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/18/2020] [Indexed: 12/13/2022]
Affiliation(s)
- Monika Krupová
- Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
- Faculty of Mathematics and PhysicsCharles University Ke Karlovu 3 12116 Prague 2 Czech Republic
| | - Jiří Kessler
- Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
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21
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Zsiros O, Ünnep R, Nagy G, Almásy L, Patai R, Székely NK, Kohlbrecher J, Garab G, Dér A, Kovács L. Role of Protein-Water Interface in the Stacking Interactions of Granum Thylakoid Membranes-As Revealed by the Effects of Hofmeister Salts. FRONTIERS IN PLANT SCIENCE 2020; 11:1257. [PMID: 32922427 PMCID: PMC7456932 DOI: 10.3389/fpls.2020.01257] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/30/2020] [Indexed: 05/08/2023]
Abstract
The thylakoid membranes of vascular plants are differentiated into stacked granum and unstacked stroma regions. The formation of grana is triggered by the macrodomain formation of photosystem II and light-harvesting complex II (PSII-LHCII) and thus their lateral segregation from the photosystem I-light-harvesting complex I (PSI-LHCI) super-complexes and the ATP-synthase; which is then stabilized by stacking interactions of the adjacent PSII-LHCII enriched regions of the thylakoid membranes. The self-assembly and dynamics of this highly organized membrane system and the nature of forces acting between the PSII-LHCII macrodomains are not well understood. By using circular dichroism (CD) spectroscopy, small-angle neutron scattering (SANS) and transmission electron microscopy (TEM), we investigated the effects of Hofmeister salts on the organization of pigment-protein complexes and on the ultrastructure of thylakoid membranes. We found that the kosmotropic agent (NH4)2SO4 and the Hofmeister-neutral NaCl, up to 2 M concentrations, hardly affected the macro-organization of the protein complexes and the membrane ultrastructure. In contrast, chaotropic salts, NaClO4, and NaSCN destroyed the mesoscopic structures, the multilamellar organization of the thylakoid membranes and the chiral macrodomains of the protein complexes but without noticeably affecting the short-range, pigment-pigment excitonic interactions. Comparison of the concentration- and time-dependences of SANS, TEM and CD parameters revealed the main steps of the disassembly of grana in the presence of chaotropes. It begins with a rapid diminishment of the long-range periodic order of the grana membranes, apparently due to an increased stacking disorder of the thylakoid membranes, as reflected by SANS experiments. SANS measurements also allowed discrimination between the cationic and anionic effects-in stacking and disorder, respectively. This step is followed by a somewhat slower disorganization of the TEM ultrastructure, due to the gradual loss of stacked membrane pairs. Occurring last is the stepwise decrease and disappearance of the long-range chiral order of the protein complexes, the rate of which was faster in LHCII-deficient membranes. These data are interpreted in terms of a theory, from our laboratory, according to which Hofmeister salts primarily affect the hydrophylic-hydrophobic interactions of proteins, and the stroma-exposed regions of the intrinsic membrane proteins, in particular-pointing to the role of protein-water interface in the stacking interactions of granum thylakoid membranes.
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Affiliation(s)
- Ottó Zsiros
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Renáta Ünnep
- Neutron Spectroscopy Department, Centre for Energy Research, Budapest, Hungary
| | - Gergely Nagy
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, Switzerland
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Budapest, Hungary
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - László Almásy
- Neutron Spectroscopy Department, Centre for Energy Research, Budapest, Hungary
| | - Roland Patai
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Noémi K. Székely
- Jülich Centre for Neutron Science at MLZ, Forschungszentrum Jülich GmbH, Garching, Germany
| | - Joachim Kohlbrecher
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czechia
- *Correspondence: Győző Garab, ; András Dér, ; László Kovács,
| | - András Dér
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
- *Correspondence: Győző Garab, ; András Dér, ; László Kovács,
| | - László Kovács
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- *Correspondence: Győző Garab, ; András Dér, ; László Kovács,
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22
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Jakšić D, Šegvić Klarić M, Crnolatac I, Šijaković Vujičić N, Smrečki V, Górecki M, Pescitelli G, Piantanida I. Unique Aggregation of Sterigmatocystin in Water Yields Strong and Specific Circular Dichroism Response Allowing Highly Sensitive and Selective Monitoring of Bio-Relevant Interactions. Mar Drugs 2019; 17:E629. [PMID: 31698712 PMCID: PMC6891739 DOI: 10.3390/md17110629] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 10/30/2019] [Accepted: 11/04/2019] [Indexed: 12/28/2022] Open
Abstract
We demonstrated the hitherto unknown property of the mycotoxin sterigmatocystin (STC) to provide homogeneous solutions in aqueous medium by forming a unique aggregate type (not formed by analogous aflatoxins), characterized by exceptionally strong circular dichroism (CD) bands in the 300-400 nm range. Results showed that these CD bands do not originate from intrinsic STC chirality but are a specific property of a peculiar aggregation process similar to psi-DNA CD response. Transmission electron microscopy (TEM) experiments revealed a fine fiber network resembling a supramolecular gel structure with helical fibers. Thermodynamic studies of aggregates by differential scanning calorimetry (DSC) revealed high reversibility of the dominant aggregation process. We demonstrated that the novel STC psi-CD band at 345 nm could be applied at biorelevant conditions (100 nanomolar concentration) and even in marine-salt content conditions for specific and quantitative monitoring of STC. Also, we showed that STC strongly non-covalently interacts with ds-DNA with likely toxic effects, thus contrary to the previous belief requiring prior enzyme epoxidation.
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Affiliation(s)
- Daniela Jakšić
- Faculty of Pharmacy and Biochemistry, Department of Microbiology, University of Zagreb, Schrottova 39, 10000 Zagreb, Croatia; (D.J.); (M.Š.K.)
| | - Maja Šegvić Klarić
- Faculty of Pharmacy and Biochemistry, Department of Microbiology, University of Zagreb, Schrottova 39, 10000 Zagreb, Croatia; (D.J.); (M.Š.K.)
| | - Ivo Crnolatac
- Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia; (I.C.); (N.Š.V.)
| | | | - Vilko Smrečki
- Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia; (I.C.); (N.Š.V.)
| | - Marcin Górecki
- Department of Chemistry, University of Pisa, via Moruzzi 13, 56124 Pisa, Italy; (M.G.); (G.P.)
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52 St., 01-224 Warsaw, Poland
| | - Gennaro Pescitelli
- Department of Chemistry, University of Pisa, via Moruzzi 13, 56124 Pisa, Italy; (M.G.); (G.P.)
| | - Ivo Piantanida
- Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia; (I.C.); (N.Š.V.)
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23
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Macroorganisation and flexibility of thylakoid membranes. Biochem J 2019; 476:2981-3018. [DOI: 10.1042/bcj20190080] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 09/19/2019] [Accepted: 10/03/2019] [Indexed: 02/07/2023]
Abstract
Abstract
The light reactions of photosynthesis are hosted and regulated by the chloroplast thylakoid membrane (TM) — the central structural component of the photosynthetic apparatus of plants and algae. The two-dimensional and three-dimensional arrangement of the lipid–protein assemblies, aka macroorganisation, and its dynamic responses to the fluctuating physiological environment, aka flexibility, are the subject of this review. An emphasis is given on the information obtainable by spectroscopic approaches, especially circular dichroism (CD). We briefly summarise the current knowledge of the composition and three-dimensional architecture of the granal TMs in plants and the supramolecular organisation of Photosystem II and light-harvesting complex II therein. We next acquaint the non-specialist reader with the fundamentals of CD spectroscopy, recent advances such as anisotropic CD, and applications for studying the structure and macroorganisation of photosynthetic complexes and membranes. Special attention is given to the structural and functional flexibility of light-harvesting complex II in vitro as revealed by CD and fluorescence spectroscopy. We give an account of the dynamic changes in membrane macroorganisation associated with the light-adaptation of the photosynthetic apparatus and the regulation of the excitation energy flow by state transitions and non-photochemical quenching.
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24
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Patty CHL, Ten Kate IL, Buma WJ, van Spanning RJM, Steinbach G, Ariese F, Snik F. Circular Spectropolarimetric Sensing of Vegetation in the Field: Possibilities for the Remote Detection of Extraterrestrial Life. ASTROBIOLOGY 2019; 19:1221-1229. [PMID: 31361507 DOI: 10.1089/ast.2019.2050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Homochirality is a generic and unique property of all biochemical life, and the fractional circular polarization of light it induces therefore constitutes a potentially unambiguous biosignature. However, while high-quality circular polarimetric spectra can be easily and quickly obtained in the laboratory, accurate measurements in the field are much more challenging due to large changes in illumination and target movement. In this study, we measured various targets in the field, up to distances of a few kilometers, using the dedicated circular spectropolarimeter TreePol. We show how photosynthetic life can readily be distinguished from abiotic matter. We underline the potential of circular polarization signals as a remotely accessible means to characterize and monitor terrestrial vegetation, for example, for agriculture and forestry. In addition, we discuss the potential of circular polarization for the remote detection of extraterrestrial life.
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Affiliation(s)
- C H Lucas Patty
- Amsterdam Institute for Molecules, Medicine and Systems (AIMMS), VU Amsterdam, Amsterdam, The Netherlands
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
- Biofotonika R&D Ltd., Szeged, Hungary
| | - Inge Loes Ten Kate
- Department of Earth Sciences, Utrecht University, Budapestlaan 4, Utrecht 3584 CD, The Netherlands
| | - Wybren Jan Buma
- HIMS, Photonics group, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Rob J M van Spanning
- Amsterdam Institute for Molecules, Medicine and Systems (AIMMS), VU Amsterdam, Amsterdam, The Netherlands
| | - Gábor Steinbach
- Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Freek Ariese
- LaserLaB, VU Amsterdam, Amsterdam, The Netherlands
| | - Frans Snik
- Leiden Observatory, Leiden University, Leiden, The Netherlands
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25
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Patty CHL, Ariese F, Buma WJ, Ten Kate IL, van Spanning RJM, Snik F. Circular spectropolarimetric sensing of higher plant and algal chloroplast structural variations. PHOTOSYNTHESIS RESEARCH 2019; 140:129-139. [PMID: 30141032 PMCID: PMC6548066 DOI: 10.1007/s11120-018-0572-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/04/2018] [Indexed: 05/11/2023]
Abstract
Photosynthetic eukaryotes show a remarkable variability in photosynthesis, including large differences in light-harvesting proteins and pigment composition. In vivo circular spectropolarimetry enables us to probe the molecular architecture of photosynthesis in a non-invasive and non-destructive way and, as such, can offer a wealth of physiological and structural information. In the present study, we have measured the circular polarizance of several multicellular green, red, and brown algae and higher plants, which show large variations in circular spectropolarimetric signals with differences in both spectral shape and magnitude. Many of the algae display spectral characteristics not previously reported, indicating a larger variation in molecular organization than previously assumed. As the strengths of these signals vary by three orders of magnitude, these results also have important implications in terms of detectability for the use of circular polarization as a signature of life.
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Affiliation(s)
- C H Lucas Patty
- Molecular Cell Physiology, VU Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
| | - Freek Ariese
- LaserLaB, VU Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands
| | - Wybren Jan Buma
- HIMS, Photonics Group, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Inge Loes Ten Kate
- Department of Earth Sciences, Utrecht University, Budapestlaan 4, 3584 CD, Utrecht, The Netherlands
| | - Rob J M van Spanning
- Systems Bioinformatics, VU Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - Frans Snik
- Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden, The Netherlands
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Abstract
In this review, we compare the circular dichroism (CD) spectra of liquid-crystalline dispersion (LCD) particles formed in PEG-containing aqueous-salt solutions with the purpose of determining the packing of ds DNA molecules in these particles. Depending on the osmotic pressure of the solution, the phase exclusion of ds DNA molecules at room temperature results in the formation of LCD particles with the cholesteric or the hexagonal packing of molecules. The heating of dispersion particles with the hexagonal packing of the ds DNA molecules results in a new phase transition, accompanied by an appearance of a new optically active phase of ds DNA molecules. Our results are rationalized by way of a concept of orientationally ordered “quasinematic” layers formed by ds DNA molecules, with a parallel alignment in the hexagonal structure. These layers can adopt a twisted configuration with a temperature increase; and as a result of this process, a new, helicoidal structure of dispersion particle is formed (termed as the “re-entrant” cholesteric phase). To prove the cholesteric pattern of ds DNA molecules in this phase, the “liquid-like” state of the dispersion particles was transformed into its “rigid” counterpart.
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Yasuda M, Oda K, Ueda T, Tabata M. Physico-chemical chlorophyll-a species in aqueous alcohol solutions determine the rate of its discoloration under UV light. Food Chem 2019; 277:463-470. [DOI: 10.1016/j.foodchem.2018.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/19/2018] [Accepted: 11/01/2018] [Indexed: 10/28/2022]
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Capretti A, Ringsmuth AK, van Velzen JF, Rosnik A, Croce R, Gregorkiewicz T. Nanophotonics of higher-plant photosynthetic membranes. LIGHT, SCIENCE & APPLICATIONS 2019; 8:5. [PMID: 30651980 PMCID: PMC6325066 DOI: 10.1038/s41377-018-0116-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 12/15/2018] [Accepted: 12/16/2018] [Indexed: 05/25/2023]
Abstract
The thylakoid membrane inside chloroplasts hosts the light-dependent reactions of photosynthesis. Its embedded protein complexes are responsible for light harvesting, excitation energy transfer, charge separation, and transport. In higher plants, when the illumination conditions vary, the membrane adapts its composition and nanoscale morphology, which is characterized by appressed and non-appressed regions known as grana and stroma lamellae, respectively. Here we investigate the nanophotonic regime of light propagation in chloroplasts of higher plants and identify novel mechanisms in the optical response of the thylakoid membrane. Our results indicate that the relative contributions of light scattering and absorption to the overall optical response of grana strongly depend on the concentration of the light-harvesting complexes. For the pigment concentrations typically found in chloroplasts, the two mechanisms have comparable strengths, and their relative value can be tuned by variations in the protein composition or in the granal diameter. Furthermore, we find that collective modes in ensembles of grana significantly increase light absorption at selected wavelengths, even in the presence of moderate biological disorder. Small variations in the granal separation or a large disorder can dismantle this collective response. We propose that chloroplasts use this mechanism as a strategy against dangerously high illumination conditions, triggering a transition to low-absorbing states. We conclude that the morphological separation of the thylakoid membrane in higher plants supports strong nanophotonic effects, which may be used by chloroplasts to regulate light absorption. This adaptive self-organization capability is of interest as a model for novel bioinspired optical materials for artificial photosynthesis, imaging, and sensing.
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Affiliation(s)
- A. Capretti
- Institute of Physics, University of Amsterdam, Amsterdam, Netherlands
| | - A. K. Ringsmuth
- Dep. Physics and Astronomy, VU University Amsterdam, Amsterdam, Netherlands
- Present Address: Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden
| | - J. F. van Velzen
- Institute of Physics, University of Amsterdam, Amsterdam, Netherlands
- Dep. Physics and Astronomy, VU University Amsterdam, Amsterdam, Netherlands
| | - A. Rosnik
- College of Chemistry, University of California, Berkeley, CA USA
| | - R. Croce
- Dep. Physics and Astronomy, VU University Amsterdam, Amsterdam, Netherlands
| | - T. Gregorkiewicz
- Institute of Physics, University of Amsterdam, Amsterdam, Netherlands
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29
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Sakurai S, Esumi M, Tanaka M. Drastic promotion of guanine oxidation via electron transfer in Ψ-type DNA. Chem Commun (Camb) 2019; 55:7695-7698. [DOI: 10.1039/c9cc02255d] [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
Drastic promotion of guanine oxidation was induced by not only intraduplex ET but also interduplex ET in Ψ-type DNA in a crowded environment using PEG.
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Affiliation(s)
- Shunsuke Sakurai
- Department of Engineering Science
- Graduate School of Informatics and Engineering
- The University of Electro-Communications
- Chofu
- Japan
| | - Mayu Esumi
- Department of Engineering Science
- Graduate School of Informatics and Engineering
- The University of Electro-Communications
- Chofu
- Japan
| | - Makiko Tanaka
- Department of Engineering Science
- Graduate School of Informatics and Engineering
- The University of Electro-Communications
- Chofu
- Japan
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30
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Jäger S, Büchel C. Cation-dependent changes in the thylakoid membrane appression of the diatom Thalassiosira pseudonana. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1860:41-51. [PMID: 30447184 DOI: 10.1016/j.bbabio.2018.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 09/21/2018] [Accepted: 11/04/2018] [Indexed: 11/16/2022]
Abstract
Diatoms show a special organisation of their plastid membranes, such that their thylakoids span the entire plastid in bands of three. While in higher plants the interaction of the light harvesting complex II and photosystem II with divalent cations (especially Mg2+) was found to take part in the interplay of electrostatic attraction and repulsion in grana membrane appression, for diatoms the key players in maintaining proper membrane distances were not identified so far. In this work, we investigated the changes in the thylakoid architecture of Thalassiosira pseudonana in reaction to different salts by using circular dichroism and fluorescence spectroscopy in combination with other techniques. We show that divalent cations have an important influence on optimal pigment organisation and thus also on maintaining membrane appression. Thereby, monovalent cations are far less effective. The concentration needed is in a physiological range and fits well with the values obtained for higher plant grana stacking, despite the fact that strict protein segregation as seen in higher plant grana is missing.
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Affiliation(s)
- Stefanie Jäger
- Institute of Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue Straße 9, 60438 Frankfurt, Germany
| | - Claudia Büchel
- Institute of Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue Straße 9, 60438 Frankfurt, Germany.
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31
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Yadav MR, Kumar M, Murumkar PR, Hazari PP, Mishra AK. Gemini Amphiphile-Based Lipoplexes for Efficient Gene Delivery: Synthesis, Formulation Development, Characterization, Gene Transfection, and Biodistribution Studies. ACS OMEGA 2018; 3:11802-11816. [PMID: 30320274 PMCID: PMC6173565 DOI: 10.1021/acsomega.8b01014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 09/10/2018] [Indexed: 06/08/2023]
Abstract
Some quaternary gemini amphiphiles (GAs) were synthesized as nonviral gene delivery carriers. The critical miceller concentration values of these amphiphiles are indicative of their superior surface-active properties. All of the synthesized GAs, alone or along with lipids like cholesterol and/or dioleoylphosphatidyl ethanolamine (DOPE), were formulated as liposomes. Formulations of GAs with DOPE showed average particle diameters of 326-400 nm with positive ζ-potential (30.1-46.4 mV). The lipoplexes of theses formulations showed complete pDNA retention at the base at a N/P ratio higher than 1.0 in gel retardation study. The GAs were effective in condensing pDNA into a ψ-phase, as indicated by circular dichroism study, and provided complete protection of the pDNA against the enzyme DNase at a N/P ratio more than 1. In vitro cell line studies showed that GA liposomal formulations caused β-gal expression and offered a higher transfection efficiency than that of liposomes prepared with the help of N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium methyl-sulfate (DOTAP)/DOPE and dicyclocarbodiimide (DCC)/DOPE but comparable to those of Lipofectamine 2000 in A549 and HeLa cell lines. Modulation of head group polarity significantly affected the transfection efficacy of GAs. The cell viabilities of almost all of the formulations were comparable to those of the standards (DCC/DOPE and DOTAP/DOPE liposomes). Incorporation of cholesterol [GA/DOPE/cholesterol in the ratio of 1:1:1] further improved the serum compatibility of the formulations and improved the transfection efficacy when evaluated in A549 and HeLa cell lines. Fluorescence-assisted cell sorting studies showed comparable number of transfected cells to Lipofectamine 2000 in the HeLa cell line. Intracellular trafficking studies using confocal microscopy indicated transfection of the HeLa cells with the reporter gene within 30 min of lipoplex treatment. γ-Scintigraphy using 99mTc-labeled lipoplexes showed higher concentrations of the lipoplexes in vital tissues like liver, spleen, lungs, and kidneys.
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Affiliation(s)
- Mange R. Yadav
- Faculty
of Pharmacy, Kalabhavan Campus, The Maharaja
Sayajirao University of Baroda, Vadodara, 390 001 Gujarat State, India
| | - Mukesh Kumar
- Faculty
of Pharmacy, Kalabhavan Campus, The Maharaja
Sayajirao University of Baroda, Vadodara, 390 001 Gujarat State, India
| | - Prashant R. Murumkar
- Faculty
of Pharmacy, Kalabhavan Campus, The Maharaja
Sayajirao University of Baroda, Vadodara, 390 001 Gujarat State, India
| | - Puja P. Hazari
- Division
of Radiopharmaceuticals, Institute of Nuclear
Medicine & Allied Sciences (INMAS), Lucknow Road, Timarpur, 110 054 Delhi, India
| | - Anil K. Mishra
- Division
of Radiopharmaceuticals, Institute of Nuclear
Medicine & Allied Sciences (INMAS), Lucknow Road, Timarpur, 110 054 Delhi, India
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32
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Yu H, Huang H, Liang J, Deng J. Twisted bio-nanorods serve as a template for constructing chiroptically active nanoflowers. NANOSCALE 2018; 10:12163-12168. [PMID: 29920569 DOI: 10.1039/c8nr03124j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Using biomacromolecule-based nanorods as a chiral source is a creative way to fabricate broadband chiroptically active nanoarchitectures. Herein, right-handedly twisted cellulose nanocrystal (CNC) nanorods, serving simultaneously as a chiral template and a building block, were combined with CuO for constructing composite nanoflowers that showed broadband chiroptical activity. Through calcination, the CuO/CNC nanoflowers can transform into chiral CuO with a flower-like architecture. The established preparation technology is expected to provide various novel broadband chiroptically active nanoarchitectures originating from CNCs and metal oxides.
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Affiliation(s)
- Huli Yu
- State Key Laboratory of Chemical Resource Engineering and College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
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33
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Průša J, Bouř P. Transition dipole coupling modeling of optical activity enhancements in macromolecular protein systems. Chirality 2017; 30:55-64. [DOI: 10.1002/chir.22778] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/14/2017] [Accepted: 10/01/2017] [Indexed: 01/24/2023]
Affiliation(s)
- Jiří Průša
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences; Prague Czech Republic
- University of Chemistry and Technology; Prague Czech Republic
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences; Prague Czech Republic
- University of Chemistry and Technology; Prague Czech Republic
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34
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Yevdokimov YM, Skuridin SG, Semenov SV, Dadinova LA, Salyanov VI, Kats EI. Re-entrant cholesteric phase in DNA liquid-crystalline dispersion particles. J Biol Phys 2017; 43:45-68. [PMID: 28028733 PMCID: PMC5323345 DOI: 10.1007/s10867-016-9433-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 10/18/2016] [Indexed: 11/24/2022] Open
Abstract
In this research, we observe and rationalize theoretically the transition from hexagonal to cholesteric packing of double-stranded (ds) DNA in dispersion particles. The samples were obtained by phase exclusion of linear ds DNA molecules from water-salt solutions of poly(ethylene glycol)-PEG-with concentrations ranging from 120 mg ml-1 to 300 mg ml-1. In the range of PEG concentrations from 120 mg ml-1 to 220 mg ml-1 at room temperature, we find ds DNA molecule packing, typical of classical cholesterics. The corresponding parameters for dispersion particles obtained at concentrations greater than 220 mg ml-1 indicate hexagonal packing of the ds DNA molecules. However, slightly counter-intuitively, the cholesteric-like packing reappears upon the heating of dispersions with hexagonal packing of ds DNA molecules. This transition occurs when the PEG concentration is larger than 220 mg ml-1. The obtained new cholesteric structure differs from the classical cholesterics observed in the PEG concentration range 120-220 mg ml-1 (hence, the term 're-entrant'). Our conclusions are based on the measurements of circular dichroism spectra, X-ray scattering curves and textures of liquid-crystalline phases. We propose a qualitative (similar to the Lindemann criterion for melting of conventional crystals) explanation of this phenomenon in terms of partial melting of so-called quasinematic layers formed by the DNA molecules. The quasinematic layers change their spatial orientation as a result of the competition between the osmotic pressure of the solvent (favoring dense, unidirectional alignment of ds DNA molecules) and twist Frank orientation energy of adjacent layers (favoring cholesteric-like molecular packing).
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Affiliation(s)
- Yuri M Yevdokimov
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, Vavilova St. 32, 119991, Moscow, Russia.
| | - Sergey G Skuridin
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, Vavilova St. 32, 119991, Moscow, Russia
| | - Sergey V Semenov
- National Research Centre 'Kurchatov Institute', Kurchatova Sq. 1, 123182, Moscow, Russia
| | - Ljubov A Dadinova
- Shubnikov Institute of Crystallography of Federal Scientific Research Centre 'Crystallography and Photonics' of the Russian Academy of Sciences, Leninskii Ave. 59, 119333, Moscow, Russia
| | - Viktor I Salyanov
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, Vavilova St. 32, 119991, Moscow, Russia
| | - Efim I Kats
- Landau Institute for Theoretical Physics of the Russian Academy of Sciences, Kosygina St. 2, 119334, Moscow, Russia
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35
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Fingerprinting the macro-organisation of pigment-protein complexes in plant thylakoid membranes in vivo by circular-dichroism spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1479-1489. [PMID: 27154055 DOI: 10.1016/j.bbabio.2016.04.287] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 04/30/2016] [Indexed: 11/24/2022]
Abstract
Macro-organisation of the protein complexes in plant thylakoid membranes plays important roles in the regulation and fine-tuning of photosynthetic activity. These delicate structures might, however, undergo substantial changes during isolating the thylakoid membranes or during sample preparations, e.g., for electron microscopy. Circular-dichroism (CD) spectroscopy is a non-invasive technique which can thus be used on intact samples. Via excitonic and psi-type CD bands, respectively, it carries information on short-range excitonic pigment-pigment interactions and the macro-organisation (chiral macrodomains) of pigment-protein complexes (psi, polymer or salt-induced). In order to obtain more specific information on the origin of the major psi-type CD bands, at around (+)506, (-)674 and (+)690nm, we fingerprinted detached leaves and isolated thylakoid membranes of wild-type and mutant plants and also tested the effects of different environmental conditions in vivo. We show that (i) the chiral macrodomains disassemble upon mild detergent treatments, but not after crosslinking the protein complexes; (ii) in different wild-type leaves of dicotyledonous and monocotyledonous angiosperms the CD features are quite robust, displaying very similar excitonic and psi-type bands, suggesting similar protein composition and (macro-) organisation of photosystem II (PSII) supercomplexes in the grana; (iii) the main positive psi-type bands depend on light-harvesting protein II contents of the membranes; (iv) the (+)506nm band appears only in the presence of PSII-LHCII supercomplexes and does not depend on the xanthophyll composition of the membranes. Hence, CD spectroscopy can be used to detect different macro-domains in the thylakoid membranes with different outer antenna compositions in vivo.
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36
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Garab G. Self-assembly and structural-functional flexibility of oxygenic photosynthetic machineries: personal perspectives. PHOTOSYNTHESIS RESEARCH 2016; 127:131-50. [PMID: 26494196 DOI: 10.1007/s11120-015-0192-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/02/2015] [Indexed: 05/24/2023]
Abstract
This short review, with a bit of historical aspect and a strong personal bias and emphases on open questions, is focusing on the (macro-)organization and structural-functional flexibilities of the photosynthetic apparatus of oxygenic photosynthetic organisms at different levels of the structural complexity-selected problems that have attracted most my attention in the past years and decades. These include (i) the anisotropic organization of the pigment-protein complexes and photosynthetic membranes-a basic organizing principle of living matter, which can, and probably should be adopted to intelligent materials; (ii) the organization of protein complexes into chiral macrodomains, large self-assembling highly organized but structurally flexible entities with unique spectroscopic fingerprints-structures, where, important, high-level regulatory functions appear to 'reside'; (iii) a novel, dissipation-assisted mechanism of structural changes, based on a thermo-optic effect: ultrafast thermal transients in the close vicinity of dissipation of unused excitation energy, which is capable of inducing elementary structural changes; it makes plants capable of responding to excess excitation with reaction rates proportional to the overexcitation above the light-saturation of photosynthesis; (iv) the 3D ultrastructure of the granum-stroma thylakoid membrane assembly and other multilamellar membrane systems, and their remodelings-associated with regulatory mechanisms; (v) the molecular organization and structural-functional plasticity of the main light-harvesting complex of plants, in relation to their crystal structure and different in vivo and in vitro states; and (vi) the enigmatic role of non-bilayer lipids and lipid phases in the bilayer thylakoid membrane-warranting its high protein content and contributing to its structural flexibility.
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37
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Duan Y, Han L, Zhang J, Asahina S, Huang Z, Shi L, Wang B, Cao Y, Yao Y, Ma L, Wang C, Dukor RK, Sun L, Jiang C, Tang Z, Nafie LA, Che S. Optically Active Nanostructured ZnO Films. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507502] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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38
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Duan Y, Han L, Zhang J, Asahina S, Huang Z, Shi L, Wang B, Cao Y, Yao Y, Ma L, Wang C, Dukor RK, Sun L, Jiang C, Tang Z, Nafie LA, Che S. Optically Active Nanostructured ZnO Films. Angew Chem Int Ed Engl 2015; 54:15170-5. [DOI: 10.1002/anie.201507502] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Indexed: 11/06/2022]
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39
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Semenov SV, Yevdokimov YM. Circular dichroism of DNA liquid-crystalline dispersion particles. Biophysics (Nagoya-shi) 2015. [DOI: 10.1134/s0006350915020177] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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40
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Tan C, Qi X, Liu Z, Zhao F, Li H, Huang X, Shi L, Zheng B, Zhang X, Xie L, Tang Z, Huang W, Zhang H. Self-Assembled Chiral Nanofibers from Ultrathin Low-Dimensional Nanomaterials. J Am Chem Soc 2015; 137:1565-71. [DOI: 10.1021/ja511471b] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Chaoliang Tan
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Xiaoying Qi
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Zhengdong Liu
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Key
Laboratory for Organic Electronics and Information Displays (KLOEID)
and Institute of Advanced Materials (IAM), Jiangsu National Synergetic
Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210046, China
| | - Fei Zhao
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Key
Laboratory for Organic Electronics and Information Displays (KLOEID)
and Institute of Advanced Materials (IAM), Jiangsu National Synergetic
Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210046, China
| | - Hai Li
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Key
Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced
Materials (IAM), Jiangsu National Synergistic Innovation Center for
Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Xiao Huang
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Key
Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced
Materials (IAM), Jiangsu National Synergistic Innovation Center for
Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Lin Shi
- Laboratory
for Nanomaterials, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
| | - Bing Zheng
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Key
Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced
Materials (IAM), Jiangsu National Synergistic Innovation Center for
Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Xiao Zhang
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Linghai Xie
- Key
Laboratory for Organic Electronics and Information Displays (KLOEID)
and Institute of Advanced Materials (IAM), Jiangsu National Synergetic
Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210046, China
| | - Zhiyong Tang
- Laboratory
for Nanomaterials, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
| | - Wei Huang
- Key
Laboratory for Organic Electronics and Information Displays (KLOEID)
and Institute of Advanced Materials (IAM), Jiangsu National Synergetic
Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210046, China
- Key
Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced
Materials (IAM), Jiangsu National Synergistic Innovation Center for
Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Hua Zhang
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
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41
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Duan Y, Liu X, Han L, Asahina S, Xu D, Cao Y, Yao Y, Che S. Optically active chiral CuO "nanoflowers". J Am Chem Soc 2014; 136:7193-6. [PMID: 24802633 DOI: 10.1021/ja500197e] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Helical symmetry can be found in most flowers with a rotation of contort petal aestivation. For micro- and nanoscale analogies, flower mimicking structures have been reproduced; however, the conceptual chirality of "nanoflowers" has not yet been defined. Here, the chirality of the "flower" was defined by its nanosized chiral structure and consequent optical activity (OA), opening new horizons for the physical theory and chiral materials. We report the surfactant-mediated hydrothermal synthesis of chiral CuO nanoflowers using sodium dodecyl sulfate (SDS) as a structure-directing agent, an amino alcohol as a symmetry-breaking agent, and cupric salt as the inorganic source. Two levels of hierarchical chirality exist for a CuO nanoflower including primary helically arranged "nanoflakes" and secondary helical "subnanopetals" that form "nanopetals". The nanoflowers exhibited a prominent optical response to circularly polarized light (CPL) at the absorption bands characteristic of CuO.
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Affiliation(s)
- Yingying Duan
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai, 200240, P. R. China
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42
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Liu B, Han L, Duan Y, Cao Y, Feng J, Yao Y, Che S. Growth of optically active chiral inorganic films through DNA self-assembly and silica mineralisation. Sci Rep 2014; 4:4866. [PMID: 24784912 PMCID: PMC4007082 DOI: 10.1038/srep04866] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/27/2014] [Indexed: 11/09/2022] Open
Abstract
The circularly polarized reflection of nature is due to their distinct azimuthally twisted or helical character in the nanostructure of the surface films. Although many chiral inorganic powders have been successfully synthesised, the artificial synthesis of chiral inorganic films is rare. Herein, we reported a facile synthetic route for the growth of monolayered chiral film on the quaternary ammonium-modified silicon substrate. The films grew on the substrate surface because of the strong electrostatic interaction between positively charged quaternary ammonium groups and negatively charged phosphate groups of DNA, with subsequent growth to right-handed, vertically aligned, impeller-like helical architectures with left-handed two-dimensional square p4mm-structured DNA chiral packing. The DNA-silica composite films exhibited strong optical activity at 295 nm and in the range of 400-800 nm, corresponding to DNA chiral packing (absorption) and to the helical blade in the impeller (scattering), respectively. Upon removal of DNA templates, the pure inorganic impeller-like helical morphology was maintained; consequently, the scattering-based optical response was blue-shifted approximately 200 nm as a result of a decrease in the effective average refractive index. The hierarchical structures were reflected from the surfaces by cross-polarised light, which confirmed that the films were strongly birefringent, with long-range anisotropy.
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Affiliation(s)
- Ben Liu
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Lu Han
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yingying Duan
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yunayuan Cao
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Ji Feng
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yuan Yao
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Shunai Che
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
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43
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Valleau S, Saikin SK, Ansari-Oghol-Beig D, Rostami M, Mossallaei H, Aspuru-Guzik A. Electromagnetic study of the chlorosome antenna complex of Chlorobium tepidum. ACS NANO 2014; 8:3884-3894. [PMID: 24641680 DOI: 10.1021/nn500759k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Green sulfur bacteria are an iconic example of nature's adaptation: thriving in environments of extremely low photon density, the bacterium ranks itself among the most efficient natural light-harvesting organisms. The photosynthetic antenna complex of this bacterium is a self-assembled nanostructure, ≈60 × 150 nm, made of bacteriochlorophyll molecules. We study the system from a computational nanoscience perspective by using electrodynamic modeling with the goal of understanding its role as a nanoantenna. Three different nanostructures, built from two molecular packing moieties, are considered: a structure built of concentric cylinders of aggregated bacteriochlorophyll d monomers, a single cylinder of bacteriochlorophyll c monomers, and a model for the entire chlorosome. The theoretical model captures both coherent and incoherent components of exciton transfer. The model is employed to extract optical spectra, concentration and depolarization of electromagnetic fields within the chlorosome, and fluxes of energy transfer for the structures. The second model nanostructure shows the largest field enhancement. Further, field enhancement is found to be more sensitive to dynamic noise rather than structural disorder. Field depolarization, however, is similar for all structures. This indicates that the directionality of transfer is robust to structural variations, while on the other hand, the intensity of transfer can be tuned by structural variations.
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Affiliation(s)
- Stéphanie Valleau
- Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States
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Garab G. Hierarchical organization and structural flexibility of thylakoid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:481-94. [PMID: 24333385 DOI: 10.1016/j.bbabio.2013.12.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 11/26/2013] [Accepted: 12/02/2013] [Indexed: 10/25/2022]
Abstract
Chloroplast thylakoid membranes accommodate densely packed protein complexes in ordered, often semi-crystalline arrays and are assembled into highly organized multilamellar systems, an organization warranting a substantial degree of stability. At the same time, they exhibit remarkable structural flexibility, which appears to play important - yet not fully understood - roles in different short-term adaptation mechanisms in response to rapidly changing environmental conditions. In this review I will focus on dynamic features of the hierarchically organized photosynthetic machineries at different levels of structural complexity: (i) isolated light harvesting complexes, (ii) molecular macroassemblies and supercomplexes, (iii) thylakoid membranes and (iv) their multilamellar membrane systems. Special attention will be paid to the most abundant systems, the major light harvesting antenna complex, LHCII, and to grana. Two physical mechanisms, which are less frequently treated in the literature, will receive special attention: (i) thermo-optic mechanism -elementary structural changes elicited by ultrafast local heat transients due to the dissipation of photon energy, which operates both in isolated antenna assemblies and the native thylakoid membranes, regulates important enzymatic functions and appears to play role in light adaptation and photoprotection mechanisms; and (ii) the mechanism by which non-bilayer lipids and lipid phases play key role in the functioning of xanthophyll cycle de-epoxidases and are proposed to regulate the protein-to-lipid ratio in thylakoid membranes and contribute to membrane dynamics. This article is part of a Special Issue entitled: Dynamic and ultrastructure of bioenergetic membranes and their components.
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Affiliation(s)
- Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, Hungary.
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Duan Y, Che S. Electron Transition-Based Optical Activity (ETOA) of Achiral Metal Oxides Derived from Chiral Mesoporous Silica. Chemistry 2013; 19:10468-72. [DOI: 10.1002/chem.201301281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Indexed: 11/11/2022]
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Liu S, Duan Y, Feng X, Yang J, Che S. Synthesis of Enantiopure Carbonaceous Nanotubes with Optical Activity. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201301199] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Liu S, Duan Y, Feng X, Yang J, Che S. Synthesis of Enantiopure Carbonaceous Nanotubes with Optical Activity. Angew Chem Int Ed Engl 2013; 52:6858-62. [DOI: 10.1002/anie.201301199] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Indexed: 11/09/2022]
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Roy S, Javid N, Frederix PWJM, Lamprou DA, Urquhart AJ, Hunt NT, Halling PJ, Ulijn RV. Dramatic Specific-Ion Effect in Supramolecular Hydrogels. Chemistry 2012; 18:11723-31. [DOI: 10.1002/chem.201201217] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Indexed: 11/06/2022]
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Nagy G, Szabó M, Unnep R, Káli G, Miloslavina Y, Lambrev PH, Zsiros O, Porcar L, Timmins P, Rosta L, Garab G. Modulation of the multilamellar membrane organization and of the chiral macrodomains in the diatom Phaeodactylum tricornutum revealed by small-angle neutron scattering and circular dichroism spectroscopy. PHOTOSYNTHESIS RESEARCH 2012; 111:71-79. [PMID: 21986933 DOI: 10.1007/s11120-011-9693-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2011] [Accepted: 09/22/2011] [Indexed: 05/26/2023]
Abstract
Diatoms possess effective photoprotection mechanisms, which may involve reorganizations in the photosynthetic machinery. We have shown earlier, by using circular dichroism (CD) spectroscopy, that in Phaeodactylum tricornutum the pigment-protein complexes are arranged into chiral macrodomains, which have been proposed to be associated with the multilamellar organization of the thylakoid membranes and shown to be capable of undergoing light-induced reversible reorganizations (Szabó et al. Photosynth Res 95:237, 2008). Recently, by using small-angle neutron scattering (SANS) on the same algal cells we have determined the repeat distances and revealed reversible light-induced reorganizations in the lamellar order of thylakoids (Nagy et al. Biochem J 436:225, 2011). In this study, we show that in moderately heat-treated samples, the weakening of the lamellar order is accompanied by the diminishment of the psi-type CD signal associated with the long-range chiral order of the chromophores (psi, polymer or salt-induced). Further, we show that the light-induced reversible increase in the psi-type CD is associated with swelling in the membrane system, with magnitudes larger in high light than in low light. In contrast, shrinkage of the membrane system, induced by sorbitol, brings about a decrease in the psi-type CD signal; this shrinkage also diminishes the non-photochemical quenching capability of the cells. These data shed light on the origin of the psi-type CD signal, and confirm that both CD spectroscopy and SANS provide valuable information on the macro-organization of the thylakoid membranes and their dynamic properties; these parameters are evidently of interest with regard to the photoprotection in whole algal cells.
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Affiliation(s)
- Gergely Nagy
- Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, P.O. Box 49, Budapest, 1215, Hungary
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O'Dell WB, Beatty KJ, Kuo-Hsiang Tang J, Blankenship RE, Urban VS, O'Neill H. Sol–gel entrapped light harvesting antennas: immobilization and stabilization of chlorosomes for energy harvesting. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm34357f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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