1
|
Sudewi S, Zulfajri M, Dayalan S, Hsu SCN, Huang GG. Glutamic acid-capped iron oxide quantum dots as fluorescent nanoprobe for tetracycline in urine. Mikrochim Acta 2023; 190:226. [PMID: 37198413 DOI: 10.1007/s00604-023-05801-3] [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: 02/14/2023] [Accepted: 04/14/2023] [Indexed: 05/19/2023]
Abstract
The fabrication of iron oxide quantum dots (IO-QDs) modified with glutamic acid (Glu) under controllable conditions is reported. The IO-QDs have been characterized by transmission electron microscopy, spectrofluorometry, powder X-ray diffraction, vibrating sample magnetometry, UV-Vis spectroscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The IO-QDs exhibited good stability towards irradiation, temperature elevations, and ionic strength, and the quantum yield (QY) of IO-QDs was calculated to be 11.91 ± 0.09%. The IO-QDs were furtherly measured at an excitation wavelength of 330 nm with emission maxima at 402 nm, which were employed to detect tetracycline (TCy) antibiotics, including tetracycline (TCy), chlortetracycline (CTCy), demeclocycline (DmCy), and oxytetracycline (OTCy) in biological samples. The results indicated that TCy, CTCy, DmCy, and OTCy in urine samples show a dynamic working range between 0.01 and 80.0 μM; 0.01 and 1.0 μM; 0.01 and 10 μM; and 0.04 and 1.0 μM, respectively, with detection limits of 7.69 nM, 120.23 nM, 18.20 nM, and 67.74 nM, respectively. The detection was not interfered with by the auto-fluorescence from the matrices. In addition, the obtained recovery in real urine samples suggested that the developed method could be used in practical applications. Therefore, the current study has prospect to develop an easy, fast, eco-friendly, and efficient new sensing method for detecting tetracycline antibiotics in biological samples.
Collapse
Affiliation(s)
- Sri Sudewi
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan
- Department of Pharmacy, Faculty of Mathematics and Natural Science, Universitas Sam Ratulangi, Manado, 95115, Indonesia
| | - Muhammad Zulfajri
- Department of Chemistry Education, Universitas Serambi Mekkah, Banda Aceh, Aceh, 23245, Indonesia
| | - Sandhiya Dayalan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan
| | - Sodio C N Hsu
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan
| | - Genin Gary Huang
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, 80708, Taiwan.
- Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan.
| |
Collapse
|
2
|
Timpmann K, Kangur L, Freiberg A. Hysteretic Pressure Dependence of Ca 2+ Binding in LH1 Bacterial Membrane Chromoproteins. J Phys Chem B 2023; 127:456-464. [PMID: 36608327 DOI: 10.1021/acs.jpcb.2c05938] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Much of the thermodynamic parameter values that support life are set by the properties of proteins. While the denaturing effects of pressure and temperature on proteins are well documented, their precise structural nature is rarely revealed. This work investigates the destabilization of multiple Ca2+ binding sites in the cyclic LH1 light-harvesting membrane chromoprotein complexes from two Ca-containing sulfur purple bacteria by hydrostatic high-pressure perturbation spectroscopy. The native (Ca-saturated) and denatured (Ca-depleted) phases of these complexes are well distinguishable by much-shifted bacteriochlorophyll a exciton absorption bands serving as innate optical probes in this study. The pressure-induced denaturation of the complexes related to the failure of the protein Ca-binding pockets and the concomitant breakage of hydrogen bonds between the pigment chromophores and protein environment were found cooperative, involving all or most of the Ca2+ binding sites, but irreversible. The strong hysteresis observed in the spectral and kinetic characteristics of phase transitions along the compression and decompression pathways implies asymmetry in the relevant free energy landscapes and activation free energy distributions. A phase transition pressure equal to about 1.9 kbar was evaluated for the complexes from Thiorhodovibrio strain 970 from the pressure dependence of biphasic kinetics observed in the minutes to 100 h time range.
Collapse
Affiliation(s)
- Kõu Timpmann
- Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu, Estonia
| | - Liina Kangur
- Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu, Estonia
| | - Arvi Freiberg
- Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu, Estonia.,Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, Estonia
| |
Collapse
|
3
|
Kaur H, Nguyen K, Kumar P. Pressure and temperature dependence of fluorescence anisotropy of green fluorescent protein. RSC Adv 2022; 12:8647-8655. [PMID: 35424839 PMCID: PMC8984833 DOI: 10.1039/d1ra08977c] [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: 12/10/2021] [Accepted: 03/11/2022] [Indexed: 11/21/2022] Open
Abstract
We have studied the effect of high hydrostatic pressure and temperature on the steady state fluorescence anisotropy of Green Fluorescent Protein (GFP). We find that the fluorescence anisotropy of GFP at a constant temperature decreases with increasing pressure. At atmospheric pressure, anisotropy decreases with increasing temperature but exhibits a maximum with temperature for pressure larger than 20 MPa. The temperature corresponding to the maximum of anisotropy increases with increasing pressure. By taking into account of the rotational correlation time changes of GFP with the pressure–temperature dependent viscosity of the solvent, we argue that viscosity increase with pressure is not a major contributing factor to the decrease in anisotropy with pressure. The decrease of anisotropy with pressure may result from changes in H-bonding environment around the chromophore. Effect of high hydrostatic pressure and temperature on the steady state fluorescence anisotropy of Green Fluorescent Protein (GFP).![]()
Collapse
Affiliation(s)
- Harpreet Kaur
- Department of Physics, University of Arkansas, Fayetteville, AR, USA
| | - Khanh Nguyen
- Department of Physics, University of Arkansas, Fayetteville, AR, USA
| | - Pradeep Kumar
- Department of Physics, University of Arkansas, Fayetteville, AR, USA
| |
Collapse
|
4
|
Mechanical regulation of photosynthesis in cyanobacteria. Nat Microbiol 2020; 5:757-767. [PMID: 32203409 DOI: 10.1038/s41564-020-0684-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 02/04/2020] [Indexed: 12/17/2022]
Abstract
Photosynthetic organisms regulate their responses to many diverse stimuli in an effort to balance light harvesting with utilizable light energy for carbon fixation and growth (source-sink regulation). This balance is critical to prevent the formation of reactive oxygen species that can lead to cell death. However, investigating the molecular mechanisms that underlie the regulation of photosynthesis in cyanobacteria using ensemble-based measurements remains a challenge due to population heterogeneity. Here, to address this problem, we used long-term quantitative time-lapse fluorescence microscopy, transmission electron microscopy, mathematical modelling and genetic manipulation to visualize and analyse the growth and subcellular dynamics of individual wild-type and mutant cyanobacterial cells over multiple generations. We reveal that mechanical confinement of actively growing Synechococcus sp. PCC 7002 cells leads to the physical disassociation of phycobilisomes and energetic decoupling from the photosynthetic reaction centres. We suggest that the mechanical regulation of photosynthesis is a critical failsafe that prevents cell expansion when light and nutrients are plentiful, but when space is limiting. These results imply that cyanobacteria must convert a fraction of the available light energy into mechanical energy to overcome frictional forces in the environment, providing insight into the regulation of photosynthesis and how microorganisms navigate their physical environment.
Collapse
|
5
|
Dang TT, Feyissa AH, Gringer N, Jessen F, Olsen K, Bøknæs N, Orlien V. Effects of high pressure and ohmic heating on shell loosening, thermal and structural properties of shrimp (Pandalus borealis). INNOV FOOD SCI EMERG 2020. [DOI: 10.1016/j.ifset.2019.102246] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
6
|
Ghosh A, Paul I, Adlung M, Wickleder C, Schmittel M. Oscillating Emission of [2]Rotaxane Driven by Chemical Fuel. Org Lett 2018; 20:1046-1049. [PMID: 29384684 DOI: 10.1021/acs.orglett.7b03996] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A molecular shuttle consisting of a dibenzo-24-crown-8 macrocycle and an axle with two degenerate peripheral triazolium stations, a central dibenzyl ammonium station, and two anthracenes stoppers was exposed to 2-cyano-2-phenylpropanoic acid as a chemical fuel. Protonation/deprotonation of the amine reversibly switches the rotaxane from a static and little emissive to a dynamic fluorescent shuttling device, the latter exhibiting rapid motion (15 kHz at 25 °C). Four fuel cycles were run.
Collapse
Affiliation(s)
- Amit Ghosh
- Center of Micro- and Nanochemistry and Engineering , Organische Chemie I, Adolf-Reichwein-Strasse 2, D-57068 Siegen, Germany
| | - Indrajit Paul
- Center of Micro- and Nanochemistry and Engineering , Organische Chemie I, Adolf-Reichwein-Strasse 2, D-57068 Siegen, Germany
| | - Matthias Adlung
- Center of Micro- and Nanochemistry and Engineering , Anorganische Chemie II, Adolf-Reichwein-Strasse 2, D-57068 Siegen, Germany
| | - Claudia Wickleder
- Center of Micro- and Nanochemistry and Engineering , Anorganische Chemie II, Adolf-Reichwein-Strasse 2, D-57068 Siegen, Germany
| | - Michael Schmittel
- Center of Micro- and Nanochemistry and Engineering , Organische Chemie I, Adolf-Reichwein-Strasse 2, D-57068 Siegen, Germany
| |
Collapse
|
7
|
Eisenberg I, Harris D, Levi-Kalisman Y, Yochelis S, Shemesh A, Ben-Nissan G, Sharon M, Raviv U, Adir N, Keren N, Paltiel Y. Concentration-based self-assembly of phycocyanin. PHOTOSYNTHESIS RESEARCH 2017; 134:39-49. [PMID: 28577216 DOI: 10.1007/s11120-017-0406-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/22/2017] [Indexed: 06/07/2023]
Abstract
Cyanobacteria light-harvesting complexes can change their structure to cope with fluctuating environmental conditions. Studying in vivo structural changes is difficult owing to complexities imposed by the cellular environment. Mimicking this system in vitro is challenging, as well. The in vivo system is highly concentrated, and handling similar in vitro concentrated samples optically is difficult because of high absorption. In this research, we mapped the cyanobacteria antennas self-assembly pathways using highly concentrated solutions of phycocyanin (PC) that mimic the in vivo condition. PC was isolated from the thermophilic cyanobacterium Thermosynechococcus vulcanus and measured by several methods. PC has three oligomeric states: hexamer, trimer, and monomer. We showed that the oligomeric state was changed upon increase of PC solution concentration. This oligomerization mechanism may enable photosynthetic organisms to adapt their light-harvesting system to a wide range of environmental conditions.
Collapse
Affiliation(s)
- Ido Eisenberg
- Applied Physics Department, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel
| | - Dvir Harris
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa, 3200003, Israel
| | - Yael Levi-Kalisman
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel
| | - Shira Yochelis
- Applied Physics Department, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel
| | - Asaf Shemesh
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel
- Institute of Chemistry, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 91904, Israel
| | - Gili Ben-Nissan
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Michal Sharon
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Uri Raviv
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel
- Institute of Chemistry, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 91904, Israel
| | - Noam Adir
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa, 3200003, Israel
| | - Nir Keren
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel
| | - Yossi Paltiel
- Applied Physics Department, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel.
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel.
| |
Collapse
|
8
|
Munday JC, Papageorgiou GC. Frederick Yi-Tung Cho (1939-2011) : His PhD days in Biophysics, the Photosynthesis Lab, and his patents in engineering physics. PHOTOSYNTHESIS RESEARCH 2017; 132:227-234. [PMID: 28523606 DOI: 10.1007/s11120-017-0391-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/25/2017] [Indexed: 06/07/2023]
Abstract
We present here a Tribute to Frederick Yi-Tung Cho (1939-2011), an innovative and ingenious biophysicist and an entrepreneur. He was one of the 4 earliest PhD students [see: Cederstrand (1965)-Carl Nelson Cederstrand; coadvisor: Eugene Rabinowitch; Papageorgiou (1968)-George C. Papageorgiou (coauthor of this paper); and Munday (1968)-John C. Munday Jr. (also a coauthor of this paper)] of one of us (Govindjee) in Biophysics at the University of Illinois at Urbana-Champaign (UIUC) during the late 1960s (1963-1968). Fred was best known, in the photosynthesis circle for his pioneering work on low temperature (down to liquid helium temperature, 4 K) absorption and fluorescence spectroscopy of photosynthetic systems; he showed temperature independence of excitation energy transfer from (i) chlorophyll (Chl) b to Chl a and (ii) from Chl a 670 to Chl a 678; and temperature dependence of energy transfer from the phycobilins to Chl a and from Chl a 678 to its suggested trap. After doing research in biophysics of photosynthesis, Fred shifted to do research in solid-state physics/engineering in the Government Electronics Division (Group) of the Motorola Company, Scottsdale, Arizona, from where he published research papers in that area and had several patents granted. We focus mainly on his days at the UIUC in context of the laboratory in which he worked. We also list some of his papers and most of his patents in engineering physics. His friends and colleagues have correctly described him as an innovator and an ingenious scientist of the highest order. On the personal side, he was a very easy-going and amiable individual.
Collapse
Affiliation(s)
- John C Munday
- College of Arts and Sciences, Regent University, Virginia Beach, VA, 23464, USA
| | - George C Papageorgiou
- Institute of Biosciences and Applications, National Center of Scientific Research ''Demokritos'', 15310, Athens, Greece
| |
Collapse
|
9
|
Ashraf I, Konrad A, Lokstein H, Skandary S, Metzger M, Djouda JM, Maurer T, Adam PM, Meixner AJ, Brecht M. Temperature dependence of metal-enhanced fluorescence of photosystem I from Thermosynechococcus elongatus. NANOSCALE 2017; 9:4196-4204. [PMID: 28287218 DOI: 10.1039/c6nr08762k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report the temperature dependence of metal-enhanced fluorescence (MEF) of individual photosystem I (PSI) complexes from Thermosynechococcus elongatus (T. elongatus) coupled to gold nanoparticles (AuNPs). A strong temperature dependence of shape and intensity of the emission spectra is observed when PSI is coupled to AuNPs. For each temperature, the enhancement factor (EF) is calculated by comparing the intensity of individual AuNP-coupled PSI to the mean intensity of 'uncoupled' PSI. At cryogenic temperature (1.6 K) the average EF was 4.3-fold. Upon increasing the temperature to 250 K the EF increases to 84-fold. Single complexes show even higher EFs up to 441.0-fold. At increasing temperatures the different spectral pools of PSI from T. elongatus become distinguishable. These pools are affected differently by the plasmonic interactions and show different enhancements. The remarkable increase of the EFs is explained by a rate model including the temperature dependence of the fluorescence yield of PSI and the spectral overlap between absorption and emission spectra of AuNPs and PSI, respectively.
Collapse
Affiliation(s)
- Imran Ashraf
- IPTC and LISA+ Center, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
| | - Alexander Konrad
- IPTC and LISA+ Center, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
| | - Heiko Lokstein
- Department of Chemical Physics and Optics, Charles University, Ke Karlovu 3, 12116 Prague, Czech Republic
| | - Sepideh Skandary
- IPTC and LISA+ Center, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
| | - Michael Metzger
- IPTC and LISA+ Center, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
| | - Joseph M Djouda
- Laboratory of Nanotechnology, Instrumentation and Optics, University of Technology of Troyes, 12 rue Marie Curie, 10004 Troyes, France
| | - Thomas Maurer
- Laboratory of Nanotechnology, Instrumentation and Optics, University of Technology of Troyes, 12 rue Marie Curie, 10004 Troyes, France
| | - Pierre M Adam
- Laboratory of Nanotechnology, Instrumentation and Optics, University of Technology of Troyes, 12 rue Marie Curie, 10004 Troyes, France
| | - Alfred J Meixner
- IPTC and LISA+ Center, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
| | - Marc Brecht
- IPTC and LISA+ Center, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
| |
Collapse
|
10
|
Silva JL, Oliveira AC, Vieira TCRG, de Oliveira GAP, Suarez MC, Foguel D. High-Pressure Chemical Biology and Biotechnology. Chem Rev 2014; 114:7239-67. [DOI: 10.1021/cr400204z] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Jerson L. Silva
- Instituto de Bioquímica Médica Leopoldo de Meis, Instituto
Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem,
Centro Nacional de Ressonância Magnética Nuclear Jiri
Jonas, and ‡Polo Xerém, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-902, Brazil
| | - Andrea C. Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Instituto
Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem,
Centro Nacional de Ressonância Magnética Nuclear Jiri
Jonas, and ‡Polo Xerém, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-902, Brazil
| | - Tuane C. R. G. Vieira
- Instituto de Bioquímica Médica Leopoldo de Meis, Instituto
Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem,
Centro Nacional de Ressonância Magnética Nuclear Jiri
Jonas, and ‡Polo Xerém, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-902, Brazil
| | - Guilherme A. P. de Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Instituto
Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem,
Centro Nacional de Ressonância Magnética Nuclear Jiri
Jonas, and ‡Polo Xerém, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-902, Brazil
| | - Marisa C. Suarez
- Instituto de Bioquímica Médica Leopoldo de Meis, Instituto
Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem,
Centro Nacional de Ressonância Magnética Nuclear Jiri
Jonas, and ‡Polo Xerém, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-902, Brazil
| | - Debora Foguel
- Instituto de Bioquímica Médica Leopoldo de Meis, Instituto
Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem,
Centro Nacional de Ressonância Magnética Nuclear Jiri
Jonas, and ‡Polo Xerém, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-902, Brazil
| |
Collapse
|
11
|
Li D, Xie J, Zhao Y, Zhao J. Probing connection of PBS with the photosystems in intact cells of Spirulina platensis by temperature-induced fluorescence fluctuation. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1557:35-40. [PMID: 12615346 DOI: 10.1016/s0005-2728(02)00392-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Temperature-dependent fluorescence for intact cells of cyanobacterium Spirulina platensis was detected to search for the connection of the phycobilisome (PBS) with Photosystem I (PSI) and Photosystem II (PSII). Some interesting results were obtained from the deconvoluted fluorescence components of C-phycocyanin (C-PC), allophycocyanin (APC), PSI and PSII as well as the fluorescence spectra of the intact cells at room temperature (RT=25 degrees C) and 0 degrees C. It was observed that, compared to those at RT, both of the fluorescence components for PSI and APC increased, whereas those for PSII and C-PC decreased at 0 degrees C with excitation at 580 nm, that is, the fluorescence for C-PC is not synchronous with that for APC, and the fluorescence fluctuation for PSI is not synchronous with that for PSII. On the other hand, the decrease in C-PC fluorescence is synchronous with the increase in PSI fluorescence, and the increase in APC fluorescence is synchronous with the decrease in PSII fluorescence. Therefore, it can be readily deduced that PBS should be coupled not only with PSII through the terminal acceptors in the APC core but also with PSI through C-PC in PBS rods at physiological condition, while at 0 degrees C, a migration of a PBS makes the APC partially detached from PSII but the C-PC more efficiently coupled with PSI. The results provide good evidences for "mobile PBS" model and "parallel connection" model but not for the "spillover" model.
Collapse
Affiliation(s)
- Donghui Li
- Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Academia Sinica, Beijing 100080, People's Republic of China
| | | | | | | |
Collapse
|
12
|
Suarez MC, Lehrer SS, Silva JL. Local heterogeneity in the pressure denaturation of the coiled-coil tropomyosin because of subdomain folding units. Biochemistry 2001; 40:1300-7. [PMID: 11170456 DOI: 10.1021/bi0020978] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Coiled-coil domains mediate the oligomerization of many proteins. The assembly of long coiled coils, such as tropomyosin, presupposes the existence of intermediates. These intermediates are not well-known for tropomyosin. Hydrostatic pressure affects the equilibrium between denatured and native forms in the direction of the form that occupies a smaller volume. The hydrophobic core is the region more sensitive to pressure, which leads in most cases to the population of intermediates. Here, we used N-(1-pyrenyl)iodoacetamide covalently bound to cysteine residues of tropomyosin (PIATm) and high hydrostatic pressure to assess the chain interaction and the inherent instability of the coiled-coil molecule. The native and denatured states of tropomyosin were determined from the pyrene excimer fluorescence. The combination of low temperature and high pressure permitted the attainment of the full denaturation of tropomyosin without the separation of the subunits. High-temperature denaturation of Tm leads to a great exchange between labeled and unlabeled Tm subunits, indicating subunit dissociation linked to unfolding. In contrast, under high pressure, unlabeled and labeled tropomyosin molecules do not exchange, demonstrating that the denatured species are dimeric. The decrease of the concentration dependence of PIATm corroborates the idea that pressure produces subdomain denaturation and that the polypeptide chains do not separate. Substantial unfolding of tropomyosin was also verified by measurements of tyrosine fluorescence and bis-ANS binding. Our results indicate the presence of independent folding subdomains with different susceptibilities to pressure along the length of the coiled-coil structure of tropomyosin.
Collapse
Affiliation(s)
- M C Suarez
- Programa de Biologia Estrutural, Departamento de Bioquímica Médica, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil
| | | | | |
Collapse
|
13
|
Oliveira AC, Ishimaru D, Gonçalves RB, Smith TJ, Mason P, Sá-Carvalho D, Silva JL. Low temperature and pressure stability of picornaviruses: implications for virus uncoating. Biophys J 1999; 76:1270-9. [PMID: 10049311 PMCID: PMC1300107 DOI: 10.1016/s0006-3495(99)77290-5] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The family Picornaviridae includes several viruses of great economic and medical importance. Poliovirus replicates in the human digestive tract, causing disease that may range in severity from a mild infection to a fatal paralysis. The human rhinovirus is the most important etiologic agent of the common cold in adults and children. Foot-and-mouth disease virus (FMDV) causes one of the most economically important diseases in cattle. These viruses have in common a capsid structure composed of 60 copies of four different proteins, VP1 to VP4, and their 3D structures show similar general features. In this study we describe the differences in stability against high pressure and cold denaturation of these viruses. Both poliovirus and rhinovirus are stable to high pressure at room temperature, because pressures up to 2.4 kbar are not enough to promote viral disassembly and inactivation. Within the same pressure range, FMDV particles are dramatically affected by pressure, with a loss of infectivity of more than 4 log units observed. The dissociation of polio and rhino viruses can be observed only under pressure (2.4 kbar) at low temperatures in the presence of subdenaturing concentrations of urea (1-2 M). The pressure and low temperature data reveal clear differences in stability among the three picornaviruses, FMDV being the most sensitive, polio being the most resistant, and rhino having intermediate stability. Whereas rhino and poliovirus differ little in stability (less than 10 kcal/mol at 0 degrees C), the difference in free energy between these two viruses and FMDV was remarkable (more than 200 kcal/mol of particle). These differences are crucial to understanding the different factors that control the assembly and disassembly of the virus particles during their life cycle. The inactivation of these viruses by pressure (combined or not with low temperature) has potential as a method for producing vaccines.
Collapse
Affiliation(s)
- A C Oliveira
- Programa de Biologia Estrutural, Centro Nacional de Ressonância Magnética Nuclear de Macromoléculas, Departamento de Bioquímica Médica-ICB, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, RJ, Brazil
| | | | | | | | | | | | | |
Collapse
|
14
|
Inoue Y, Matsushima E, Wada T. Pressure and Temperature Control of Product Chirality in Asymmetric Photochemistry. Enantiodifferentiating Photoisomerization of Cyclooctene Sensitized by Chiral Benzenepolycarboxylates. J Am Chem Soc 1998. [DOI: 10.1021/ja981929a] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yoshihisa Inoue
- Contribution from the Inoue Photochirogenesis Project, ERATO, JST, 4-6-3 Kamishinden, Toyonaka 565-0085, Japan, and Department of Molecular Chemistry, Faculty of Engineering, Osaka University, 2-1 Yamada-oka, Suita 565-0871, Japan
| | - Eiji Matsushima
- Contribution from the Inoue Photochirogenesis Project, ERATO, JST, 4-6-3 Kamishinden, Toyonaka 565-0085, Japan, and Department of Molecular Chemistry, Faculty of Engineering, Osaka University, 2-1 Yamada-oka, Suita 565-0871, Japan
| | - Takehiko Wada
- Contribution from the Inoue Photochirogenesis Project, ERATO, JST, 4-6-3 Kamishinden, Toyonaka 565-0085, Japan, and Department of Molecular Chemistry, Faculty of Engineering, Osaka University, 2-1 Yamada-oka, Suita 565-0871, Japan
| |
Collapse
|
15
|
Gaspar LP, Johnson JE, Silva JL, Da Poian AT. Partially folded states of the capsid protein of cowpea severe mosaic virus in the disassembly pathway. J Mol Biol 1997; 273:456-66. [PMID: 9344752 DOI: 10.1006/jmbi.1997.1299] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The different partially folded states of the capsid protein that appear in the disassembly pathway of cowpea severe mosaic virus (CPSMV) were investigated by examining the effects of hydrostatic pressure, sub-zero temperatures and urea. The conformational states of the coat protein were analyzed by their intrinsic fluorescence, binding of bis(8-anilinonaphthalene-1-sulfonate) (bis-ANS) and susceptibility to trypsin digestion. CPSMV could be disassembled by pressure at 2.5 kbar. Intrinsic fluorescence and hydrodynamic measurements showed that pressure-induced dissociation was completely reversible. Virus pressurization in the presence of ribonuclease revealed that viral RNA was not exposed, since it was not digested by the enzyme, suggesting the maintenance of protein-nucleic acid interactions under pressure. When the temperature was decreased to -10 degrees C under pressure, CPSMV disassembly became an irreversible process and in this condition, viral RNA was completely digested by ribonuclease. These results suggest a relationship between protein-RNA interactions and CPSMV assembly. Bis-ANS binding and trypsin digestion of coat proteins revealed that they assume a different conformation when they are denatured by low temperatures under pressure or than when they are denatured by urea at atmospheric pressure. The results indicate that the coat proteins can exist in at least four states: (1) The native conformation in the virus capsid; (2) bound to RNA when the virus is dissociated by pressure at room temperature, assuming a conformation that retains the information for reassembly; (3) free subunits in a molten-globule conformation when the virus is dissociated by low temperature under pressure; and (4) free subunits completely unfolded by high concentrations of urea.
Collapse
Affiliation(s)
- L P Gaspar
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-590, Brazil
| | | | | | | |
Collapse
|
16
|
Silva JL, Foguel D, Da Poian AT, Prevelige PE. The use of hydrostatic pressure as a tool to study viruses and other macromolecular assemblages. Curr Opin Struct Biol 1996; 6:166-75. [PMID: 8728649 DOI: 10.1016/s0959-440x(96)80071-6] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Recent studies on the effect of pressure on macromolecular assemblages have provided new information on protein-protein and protein-nucleic acid interactions. New findings have recently emerged on the use of hydrostatic pressure to assess intermediate states in the assembly pathways of viruses, multimeric proteins and protein-nucleic acid complexes, addressing many questions of macromolecular recognition.
Collapse
Affiliation(s)
- J L Silva
- Departamento de Bioquimica Médica, Universidade Federal do Rio de Janeiro, Brazil.
| | | | | | | |
Collapse
|
17
|
Foguel D, Weber G. Pressure-induced dissociation and denaturation of allophycocyanin at subzero temperatures. J Biol Chem 1995; 270:28759-66. [PMID: 7499398 DOI: 10.1074/jbc.270.48.28759] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The thermodynamics of assembly of the allophycocyanin hexamer was examined employing hydrostatic pressures in the range of 1 bar to 2.4 kbar and temperatures of 20 to -12 degrees C, the latter made possible by the decrease of the freezing point of water under pressure. The existence of two processes, dissociation of the hexamer into dimers, (alpha beta)3-->3 (alpha beta), and dissociation of the alpha beta dimers into monomers, (alpha beta)-->alpha + beta have been recognized previously by changes in the absorbance and fluorescence of the tetrapyrrolic chromophores owing to added ligands. The same changes are observed in the absence of ligands at pressures of under 2.4 kbar and temperatures down to -12 degrees C. On decompression from 2.4 kbar at 0 degrees C, appreciable hysteresis and a persistent loss of 50% in the absorbance at 653 nm is observed. It results from the conformational drift of the isolated subunits and is reduced to 10% when the highest pressure is limited to 1.6 kbar. The thermodynamic parameters of the reaction alpha + beta-->alpha beta can be determined from pressure effects on perchlorate solutions of allophycocyanin, which consist of dimers alone. Their previous knowledge permits estimation, under suitable hypotheses, of the thermodynamic parameters of the reaction 3(alpha beta)-->(alpha beta)3 from the overall pressure effects on the hexamers. Both association reactions have positive enthalpy changes, and the whole hexamer assembly is made possible by the excess entropy.
Collapse
Affiliation(s)
- D Foguel
- Department of Biochemistry, School of Chemical Science, University of Illinois, Urbana 61801, USA
| | | |
Collapse
|
18
|
Prevelige PE, King J, Silva JL. Pressure denaturation of the bacteriophage P22 coat protein and its entropic stabilization in icosahedral shells. Biophys J 1994; 66:1631-41. [PMID: 8061212 PMCID: PMC1275883 DOI: 10.1016/s0006-3495(94)80955-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The pressure stability of bacteriophage P22 coat protein in both monomeric and polymeric forms under hydrostatic pressure was examined using light scattering, fluorescence emission, polarization, and lifetime methodology. The monomeric protein is very unstable toward pressure and undergoes significant structural changes at pressures as low as 0.5 kbar. These structural changes ultimately lead to denaturation of the subunit. Comparison of the protein denatured by pressure to that in guanidine hydrochloride suggests that pressure results in partial unfolding, perhaps by a domain mechanism. Fluorescence lifetime measurements indicate that at atmospheric pressure the local environments of the tryptophans are remarkably similar, suggesting they may be clustered. In contrast to the monomeric protein subunit, the protein when polymerized into procapsid shells is very stable to applied pressure and does not dissociate with pressure up to 2.5 kbar. However, under applied pressure the procapsid shells are cold-labile, suggesting they are entropically stabilized. The significance of these results in terms of virus assembly are discussed.
Collapse
Affiliation(s)
- P E Prevelige
- Boston Biomedical Research Institute, Massachusetts 02114
| | | | | |
Collapse
|
19
|
Freiberg A, Ellervee A, Kukk P, Laisaar A, Tars M, Timpmann K. Pressure effects on spectra of photosynthetic light-harvesting pigment-protein complexes. Chem Phys Lett 1993. [DOI: 10.1016/0009-2614(93)85447-v] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|