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Khatun R, Dolai M, Sasmal M, Katarkar A, Islam ASM, Yasmin N, Maryum S, Haribabu J, Ali M. Small molecule interactions with biomacromolecules: selective sensing of human serum albumin by a hexanuclear manganese complex - photophysical and biological studies. J Mater Chem B 2024; 12:9408-9419. [PMID: 39192836 DOI: 10.1039/d4tb00712c] [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: 08/29/2024]
Abstract
A covalently bonded hexanuclear neutral complex, [Mn6(μ3-O)2(3-MeO-salox)6(OAc)2(H2O)4] (1), has been synthesized and characterized by single crystal X-ray diffraction analysis along with IR and HRMS studies. Complex 1 has been found to selectively interact with human serum albumin (HSA), a model transport protein. The interaction of 1 with HSA was investigated by monitoring the change in the absorbance value of HSA at λ = 280 nm with increasing concentration of 1. Likewise, fluorescence titrations were carried out under two conditions: (i) titration of a 5 μM solution of complex 1 with the gradual addition of HSA, showing a ∼9-fold fluorescence intensity enhancement at 424 nm, upon excitation at 300 nm; and (ii) upon excitation at 295 nm, titration of 5 μM HSA solution with the incremental addition of complex 1, showing a quenching of fluorescence intensity at 334 nm, with simultaneous development of a new emission band at 424 nm. A linear form of the Stern-Volmer equation gives KSV = 9.77 × 104 M-1 and the Benesi-Hildebrand plot yields the binding constant as KBH = 1.98 × 105 M-1 at 298 K. The thermodynamic parameters, ΔS°, ΔH°, and ΔG°, were estimated by using the van't Hoff relationship which infer the major contribution of hydrophobic interactions between HSA and 1. It was observed that quenching of HSA emission arises mainly through a dynamic quenching mechanism as indicated by the dependence of average lifetime 〈τ〉 on the concentration of 1. The changes in the CD (circular dichroism) spectral pattern of HSA in the presence of 1 clearly establish the variation of HSA secondary structure on interaction with 1. The most probable interaction region in HSA for 1 was determined from molecular docking studies which establish the preferential trapping of 1 in the subdomain IIA of site I in HSA and substantiated by the results of site-specific marker studies. Complex 1 was further evaluated for its antiproliferative effects in lung cancer A549 cells, which strictly inhibits the growth of the cells in both 2D and 3D mammospheres, indicating its potential application as an anticancer drug.
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Affiliation(s)
- Rousunara Khatun
- Department of Chemistry, Jadavpur University, 188, Raja S. C. Mullick Road, Kolkata 700 032, India.
- Aliah University, ll-A/27, Action Area II, Newtown, Action Area II, Kolkata, West Bengal 700160, India
| | - Malay Dolai
- Department of Chemistry, Prabhat Kumar College, Purba Medinipur 721404, India
| | - Mihir Sasmal
- Department of Chemistry, Jadavpur University, 188, Raja S. C. Mullick Road, Kolkata 700 032, India.
| | - Atul Katarkar
- Department of Biochemistry, University of Lausanne, 1066 Epalinges, Switzerland
| | - Abu Saleh Musha Islam
- School of Chemical Sciences, Indian Association for the Cultivation of Science, & 2B Raja S.C. Mullick Road, Kolkata 700032, India
| | - Nasima Yasmin
- Aliah University, ll-A/27, Action Area II, Newtown, Action Area II, Kolkata, West Bengal 700160, India
| | - Sana Maryum
- Department of Chemistry, Jadavpur University, 188, Raja S. C. Mullick Road, Kolkata 700 032, India.
| | - Jebiti Haribabu
- Facultad de Medicina, Universidad de Atacama, Los Carreras 1579, 1532502 Copiapo, Chile
- Chennai Institute of Technology (CIT), Chennai 600069, India
| | - Mahammad Ali
- Department of Chemistry, Jadavpur University, 188, Raja S. C. Mullick Road, Kolkata 700 032, India.
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2
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Proksch J, Dal Colle MCS, Heinz F, Schmidt RF, Gottwald J, Delbianco M, Keller BG, Gradzielski M, Alexiev U, Koksch B. Impact of glycan nature on structure and viscoelastic properties of glycopeptide hydrogels. J Pept Sci 2024; 30:e3599. [PMID: 38567550 DOI: 10.1002/psc.3599] [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: 01/30/2024] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 04/04/2024]
Abstract
Mucus is a complex biological hydrogel that acts as a barrier for almost everything entering or exiting the body. It is therefore of emerging interest for biomedical and pharmaceutical applications. Besides water, the most abundant components are the large and densely glycosylated mucins, glycoproteins of up to 20 MDa and carbohydrate content of up to 80 wt%. Here, we designed and explored a library of glycosylated peptides to deconstruct the complexity of mucus. Using the well-characterized hFF03 coiled-coil system as a hydrogel-forming peptide scaffold, we systematically probed the contribution of single glycans to the secondary structure as well as the formation and viscoelastic properties of the resulting hydrogels. We show that glycan-decoration does not affect α-helix and coiled-coil formation while it alters gel stiffness. By using oscillatory macrorheology, dynamic light scattering microrheology, and fluorescence lifetime-based nanorheology, we characterized the glycopeptide materials over several length scales. Molecular simulations revealed that the glycosylated linker may extend into the solvent, but more frequently interacts with the peptide, thereby likely modifying the stability of the self-assembled fibers. This systematic study highlights the interplay between glycan structure and hydrogel properties and may guide the development of synthetic mucus mimetics.
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Affiliation(s)
- Jonas Proksch
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Marlene C S Dal Colle
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Frederick Heinz
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Robert F Schmidt
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Berlin, Germany
| | | | - Martina Delbianco
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Bettina G Keller
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Berlin, Germany
| | - Michael Gradzielski
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Berlin, Germany
| | - Ulrike Alexiev
- Department of Physics, Freie Universität Berlin, Berlin, Germany
| | - Beate Koksch
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
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Schanda P, Haran G. NMR and Single-Molecule FRET Insights into Fast Protein Motions and Their Relation to Function. Annu Rev Biophys 2024; 53:247-273. [PMID: 38346243 DOI: 10.1146/annurev-biophys-070323-022428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Proteins often undergo large-scale conformational transitions, in which secondary and tertiary structure elements (loops, helices, and domains) change their structures or their positions with respect to each other. Simple considerations suggest that such dynamics should be relatively fast, but the functional cycles of many proteins are often relatively slow. Sophisticated experimental methods are starting to tackle this dichotomy and shed light on the contribution of large-scale conformational dynamics to protein function. In this review, we focus on the contribution of single-molecule Förster resonance energy transfer and nuclear magnetic resonance (NMR) spectroscopies to the study of conformational dynamics. We briefly describe the state of the art in each of these techniques and then point out their similarities and differences, as well as the relative strengths and weaknesses of each. Several case studies, in which the connection between fast conformational dynamics and slower function has been demonstrated, are then introduced and discussed. These examples include both enzymes and large protein machines, some of which have been studied by both NMR and fluorescence spectroscopies.
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Affiliation(s)
- Paul Schanda
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria;
| | - Gilad Haran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel;
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4
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Gottwald J, Balke J, Stellmacher J, van Vorst K, Ghazisaeedi F, Fulde M, Alexiev U. Cy3-Based Nanoviscosity Determination of Mucus: Effect of Mucus Collection Methods and Antibiotics Treatment. Macromol Biosci 2024:e2300437. [PMID: 38625085 DOI: 10.1002/mabi.202300437] [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: 09/25/2023] [Revised: 12/21/2023] [Indexed: 04/17/2024]
Abstract
The integrity of the protective mucus layer as a primary defense against pathogen invasion and microbial leakage into the intestinal epithelium can be compromised by the effects of antibiotics on the commensal microbiome. Changes in mucus integrity directly affect the solvent viscosity in the immediate vicinity of the mucin network, that is, the nanoviscosity, which in turn affects both biochemical reactions and selective transport. To assess mucus nanoviscosity, a reliable readout via the viscosity-dependent fluorescence lifetime of the molecular rotor dye cyanine 3 is established and nanoviscosities from porcine and murine ex vivo mucus are determined. To account for different mucin concentrations due to the removal of digestive residues during mucus collection, the power law dependence of mucin concentration on viscosity is used. The impact of antibiotics combinations (meropenem/vancomycin, gentamycin/ampicillin) on ex vivo intestinal mucus nanoviscosity is presented. The significant increase in viscosity of murine intestinal mucus after treatment suggests an effect of antibiotics on the microbiota that affects mucus integrity. This method will be a useful tool to assess how drugs, directly or indirectly, affect mucus integrity. Additionally, the method can be utilized to analyze the role of mucus nanoviscosity in health and disease, as well as in drug development.
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Affiliation(s)
- Jacqueline Gottwald
- Physics Department, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Jens Balke
- Physics Department, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Johannes Stellmacher
- Physics Department, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Kira van Vorst
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Robert-von-Ostertag-Str. 7, 14163, Berlin, Germany
| | - Fereshteh Ghazisaeedi
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Robert-von-Ostertag-Str. 7, 14163, Berlin, Germany
| | - Marcus Fulde
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Robert-von-Ostertag-Str. 7, 14163, Berlin, Germany
| | - Ulrike Alexiev
- Physics Department, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
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Porta-de-la-Riva M, Morales-Curiel LF, Carolina Gonzalez A, Krieg M. Bioluminescence as a functional tool for visualizing and controlling neuronal activity in vivo. NEUROPHOTONICS 2024; 11:024203. [PMID: 38348359 PMCID: PMC10861157 DOI: 10.1117/1.nph.11.2.024203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 02/15/2024]
Abstract
The use of bioluminescence as a reporter for physiology in neuroscience is as old as the discovery of the calcium-dependent photon emission of aequorin. Over the years, luciferases have been largely replaced by fluorescent reporters, but recently, the field has seen a renaissance of bioluminescent probes, catalyzed by unique developments in imaging technology, bioengineering, and biochemistry to produce luciferases with previously unseen colors and intensity. This is not surprising as the advantages of bioluminescence make luciferases very attractive for noninvasive, longitudinal in vivo observations without the need of an excitation light source. Here, we review how the development of dedicated and specific sensor-luciferases afforded, among others, transcranial imaging of calcium and neurotransmitters, or cellular metabolites and physical quantities such as forces and membrane voltage. Further, the increased versatility and light output of luciferases have paved the way for a new field of functional bioluminescence optogenetics, in which the photon emission of the luciferase is coupled to the gating of a photosensor, e.g., a channelrhodopsin and we review how they have been successfully used to engineer synthetic neuronal connections. Finally, we provide a primer to consider important factors in setting up functional bioluminescence experiments, with a particular focus on the genetic model Caenorhabditis elegans, and discuss the leading challenges that the field needs to overcome to regain a competitive advantage over fluorescence modalities. Together, our paper caters to experienced users of bioluminescence as well as novices who would like to experience the advantages of luciferases in their own hand.
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Affiliation(s)
- Montserrat Porta-de-la-Riva
- ICFO—Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Luis-Felipe Morales-Curiel
- ICFO—Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Adriana Carolina Gonzalez
- ICFO—Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Michael Krieg
- ICFO—Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
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Braslavsky SE. Outstanding women scientists who have broadened the knowledge on biological photoreceptors-II. Photochem Photobiol Sci 2024; 23:757-761. [PMID: 38446404 DOI: 10.1007/s43630-024-00551-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/08/2024] [Indexed: 03/07/2024]
Abstract
This part II is a continuation of the article published in Photochemical and Photobiological Sciences (2023) 22, 2799-2815, https://doi.org/10.1007/s43630-023-00487-1 , which should be considered a work in progress. Now, two female scientists who have worked on different aspects of chronobiology, plus a younger colleague who recently and too prematurely died, are incorporated to the list of outstanding women who have expanded the knowledge in the field of biological photoreceptors.
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Affiliation(s)
- Silvia E Braslavsky
- Max Planck Institute for Chemical Energy Conversion, 45410, Mülheim an der Ruhr, Germany.
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Çeper T, Langer M, Vashistha N, Dietzek-Ivanšić B, Streb C, Rau S, Schacher FH. Poly(dehydroalanine)-Based Hydrogels as Efficient Soft Matter Matrices for Light-Driven Catalysis. Macromol Rapid Commun 2024; 45:e2300448. [PMID: 38232973 DOI: 10.1002/marc.202300448] [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: 07/26/2023] [Revised: 11/27/2023] [Indexed: 01/19/2024]
Abstract
Soft matter integration of photosensitizers and catalysts provides promising solutions to developing sustainable materials for energy conversion. Particularly, hydrogels bring unique benefits, such as spatial control and 3D-accessibility of molecular units, as well as recyclability. Herein, the preparation of polyampholyte hydrogels based on poly(dehydroalanine) (PDha) is reported. Chemically crosslinked PDha with bis-epoxy poly(ethylene glycol) leads to a transparent, self-supporting hydrogel. Due to the ionizable groups on PDha, this 3D polymeric matrix can be anionic, cationic, or zwitterionic depending on the pH value, and its high density of dynamic charges has a potential for electrostatic attachment of charged molecules. The integration of the cationic molecular photosensitizer [Ru(bpy)3 ]2+ (bpy = 2,2'-bipyridine) is realized, which is a reversible process controlled by pH, leading to light harvesting hydrogels. They are further combined with either a thiomolybdate catalyst ([Mo3 S13 ]2- ) for hydrogen evolution reaction (HER) or a cobalt polyoxometalate catalyst (Co4 POM = [Co4 (H2 O)2 (PW9 O34 )2 ]10- ) for oxygen evolution reaction (OER). Under the optimized condition, the resulting hydrogels show catalytic activity in both cases upon visible light irradiation. In the case of OER, higher photosensitizer stability is observed compared to homogeneous systems, as the polymer environment seems to influence decomposition pathways.
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Affiliation(s)
- Tolga Çeper
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, Humboldtstraße 10, D-07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, D-07743, Jena, Germany
- Center for Energy and Environmental Chemistry Jena (CEEC), Friedrich Schiller University Jena, Philosophenweg 7a, 07743, Jena, Germany
| | - Marcel Langer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Nikita Vashistha
- Institute of Physical Chemistry, Friedrich-Schiller-University Jena, Helmholtzweg 4, D-07743, Jena, Germany
- Leibniz Institute of Photonic Technology Jena, Department of Functional Interfaces, Albert Einstein Allee 9, D-07745, Jena, Germany
| | - Benjamin Dietzek-Ivanšić
- Institute of Physical Chemistry, Friedrich-Schiller-University Jena, Helmholtzweg 4, D-07743, Jena, Germany
- Leibniz Institute of Photonic Technology Jena, Department of Functional Interfaces, Albert Einstein Allee 9, D-07745, Jena, Germany
| | - Carsten Streb
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Sven Rau
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Felix H Schacher
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, Humboldtstraße 10, D-07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, D-07743, Jena, Germany
- Center for Energy and Environmental Chemistry Jena (CEEC), Friedrich Schiller University Jena, Philosophenweg 7a, 07743, Jena, Germany
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Alexiev U, Rühl E. Visualization of Nanocarriers and Drugs in Cells and Tissue. Handb Exp Pharmacol 2024; 284:153-189. [PMID: 37566121 DOI: 10.1007/164_2023_684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
In this chapter, the visualization of nanocarriers and drugs in cells and tissue is reviewed. This topic is tightly connected to modern drug delivery, which relies on nanoscopic drug formulation approaches and the ability to probe nanoparticulate systems selectively in cells and tissue using advanced spectroscopic and microscopic techniques. We first give an overview of the breadth of this research field. Then, we mainly focus on topical drug delivery to the skin and discuss selected visualization techniques from spectromicroscopy, such as scanning transmission X-ray microscopy and fluorescence lifetime imaging. These techniques rely on the sensitive and quantitative detection of the topically applied drug delivery systems and active substances, either by exploiting their molecular properties or by introducing environmentally sensitive probes that facilitate their detection.
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Affiliation(s)
- Ulrike Alexiev
- Fachbereich Physik, Freie Universität Berlin, Berlin, Germany.
| | - Eckart Rühl
- Physikalische Chemie, Freie Universität Berlin, Berlin, Germany.
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9
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Fossum CJ, Johnson BOV, Golde ST, Kielman AJ, Finke B, Smith MA, Lowater HR, Laatsch BF, Bhattacharyya S, Hati S. Insights into the Mechanism of Tryptophan Fluorescence Quenching due to Synthetic Crowding Agents: A Combined Experimental and Computational Study. ACS OMEGA 2023; 8:44820-44830. [PMID: 38046287 PMCID: PMC10688029 DOI: 10.1021/acsomega.3c06006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/28/2023] [Accepted: 10/31/2023] [Indexed: 12/05/2023]
Abstract
Intrinsic tryptophan fluorescence spectroscopy is an important tool for examining the effects of molecular crowding and confinement on the structure, dynamics, and function of proteins. Synthetic crowders such as dextran, ficoll, polyethylene glycols, polyvinylpyrrolidone, and their respective monomers are used to mimic crowded intracellular environments. Interactions of these synthetic crowders with tryptophan and the subsequent impact on its fluorescence properties are therefore critically important for understanding the possible interference created by these crowders. In the present study, the effects of polymer and monomer crowders on tryptophan fluorescence were assessed by using experimental and computational approaches. The results of this study demonstrated that both polymer and monomer crowders have an impact on the tryptophan fluorescence intensity; however, the molecular mechanisms of quenching were different. Using Stern-Volmer plots and a temperature variation study, a physical basis for the quenching mechanism of commonly used synthetic crowders was established. The quenching of free tryptophan was found to involve static, dynamic, and sphere-of-action mechanisms. In parallel, computational studies employing Kohn-Sham density functional theory provided a deeper insight into the effects of intermolecular interactions and solvation, resulting in differing quenching modes for these crowders. Taken together, the study offers new physical insights into the quenching mechanisms of some commonly used monomer and polymer synthetic crowders.
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Affiliation(s)
| | - Benjamin O. V. Johnson
- Department of Chemistry and
Biochemistry, University of Wisconsin-Eau
Claire, Eau Claire, Wisconsin 54701, United States
| | - Spencer T. Golde
- Department of Chemistry and
Biochemistry, University of Wisconsin-Eau
Claire, Eau Claire, Wisconsin 54701, United States
| | - Alexis J. Kielman
- Department of Chemistry and
Biochemistry, University of Wisconsin-Eau
Claire, Eau Claire, Wisconsin 54701, United States
| | - Brianna Finke
- Department of Chemistry and
Biochemistry, University of Wisconsin-Eau
Claire, Eau Claire, Wisconsin 54701, United States
| | - Macey A. Smith
- Department of Chemistry and
Biochemistry, University of Wisconsin-Eau
Claire, Eau Claire, Wisconsin 54701, United States
| | - Harrison R. Lowater
- Department of Chemistry and
Biochemistry, University of Wisconsin-Eau
Claire, Eau Claire, Wisconsin 54701, United States
| | - Bethany F. Laatsch
- Department of Chemistry and
Biochemistry, University of Wisconsin-Eau
Claire, Eau Claire, Wisconsin 54701, United States
| | - Sudeep Bhattacharyya
- Department of Chemistry and
Biochemistry, University of Wisconsin-Eau
Claire, Eau Claire, Wisconsin 54701, United States
| | - Sanchita Hati
- Department of Chemistry and
Biochemistry, University of Wisconsin-Eau
Claire, Eau Claire, Wisconsin 54701, United States
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Wolf A, Volz-Rakebrand P, Balke J, Alexiev U. Diffusion Analysis of NAnoscopic Ensembles: A Tracking-Free Diffusivity Analysis for NAnoscopic Ensembles in Biological Samples and Nanotechnology. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206722. [PMID: 36670094 DOI: 10.1002/smll.202206722] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/16/2022] [Indexed: 06/17/2023]
Abstract
The rapid development of microscopic techniques over the past decades enables the establishment of single molecule fluorescence imaging as a powerful tool in biological and biomedical sciences. Single molecule fluorescence imaging allows to study the chemical, physicochemical, and biological properties of target molecules or particles by tracking their molecular position in the biological environment and determining their dynamic behavior. However, the precise determination of particle distribution and diffusivities is often challenging due to high molecule/particle densities, fast diffusion, and photobleaching/blinking of the fluorophore. A novel, accurate, and fast statistical analysis tool, Diffusion Analysis of NAnoscopic Ensembles (DANAE), that solves all these obstacles is introduced. DANAE requires no approximations or any a priori input regarding unknown system-inherent parameters, such as background distributions; a requirement that is vitally important when studying the behavior of molecules/particles in living cells. The superiority of DANAE with various data from simulations is demonstrated. As experimental applications of DANAE, membrane receptor diffusion in its natural membrane environment, and cargo mobility/distribution within nanostructured lipid nanoparticles are presented. Finally, the method is extended to two-color channel fluorescence microscopy.
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Affiliation(s)
- Alexander Wolf
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Pierre Volz-Rakebrand
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Jens Balke
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Ulrike Alexiev
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
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11
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Kapoor L, Udhaya Kumar S, De S, Vijayakumar S, Kapoor N, Ashok Kumar SK, Priya Doss C G, Ramamoorthy S. Multispectroscopic, virtual and in vivo insights into the photoaging defense mediated by the natural food colorant bixin. Food Funct 2023; 14:319-334. [PMID: 36503930 DOI: 10.1039/d2fo02338e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
An upsurge in early onset of photoaging due to repeated skin exposure to environmental stressors such as UV radiation is a challenge for pharmaceutical and cosmeceutical divisions. Current reports indicate severe side effects because of chemical or synthetic inhibitors of matrix metalloproteases (MMPs) in anti-skin aging cosmeceuticals. We evaluated the adequacy of bixin, a well-known FDA certified food additive, as a scavenger of free radicals and its inhibitory mechanism of action on MMP1, collagenase, elastase, and hyaluronidase. The anti-skin aging potential of bixin was evaluated by several biotechnological tools in silico, in vitro and in vivo. Molecular docking and simulation dynamics studies gave a virtual insight into the robust binding interaction between bixin and skin aging-related enzymes. Absorbance and fluorescence studies, enzyme inhibition assays, enzyme kinetics and in vitro bioassays of human dermal fibroblast (HDF) cells highlighted bixin's role as a potent antioxidant and inhibitor of skin aging-related enzymes. Furthermore, in vivo protocols were carried out to study the impact of bixin administration on UVA induced photoaging in C57BL/6 mice skin. Here, we uncover the UVA shielding effect of bixin and its efficacy as a novel anti-photoaging agent. Furthermore, the findings of this study provide a strong foundation to explore the pharmaceutical applications of bixin in several other biochemical pathways linked to MMP1, collagenase, elastase, and hyaluronidase.
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Affiliation(s)
- Leepica Kapoor
- School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
| | - S Udhaya Kumar
- School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
| | - Sourav De
- Department of Chemical Engineering, National Chung Cheng University, Chia-Yi, 62102, Taiwan
| | - Sujithra Vijayakumar
- School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
| | - Nitin Kapoor
- Department of Endocrinology, Diabetes and Metabolism, Christian Medical College, Vellore 632004, Tamil Nadu, India.,Non Communicable Disease Unit and Implementation Science Lab, The Baker Heart and Diabetes Institute, Melbourne, VIC, 3004, Australia
| | - S K Ashok Kumar
- School of Advanced Sciences, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India
| | - George Priya Doss C
- School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
| | - Siva Ramamoorthy
- School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
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12
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Ning K, Fu Y, Wu J, Sun Y, Liu K, Ye K, Liu J, Wu Y, Liang J. Inner filter effect-based red-shift and fluorescence dual-sensor platforms with sulfur quantum dots for detection and bioimaging of alkaline phosphatase. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2022; 15:79-86. [PMID: 36484164 DOI: 10.1039/d2ay01658c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Alkaline phosphatase (ALP), one of the vital biomarkers in several diseases, plays a role in indicating disease presence or severity in early diagnosis. Here, a simple H2O2 assisted top-down method was used to synthesize sulfur quantum dots (SQDs) with excitation and emission at 355 nm and 440 nm. Adding ALP into p-nitrophenyl phosphate (p-NPP) and SQDs was found to exhibit a red shift in the emission wavelength and fluorescence intensity quenching of SQDs, respectively, allowing us to propose dual-sensor platforms of red shift of emission wavelength (RSEW) and fluorescence quenching of SQDs. These dual-sensor platforms were highly sensitive and selective in ALP detection, with a linear response to ALP in the concentration range of 0.25 to 100 U L-1 and detection limits of 0.08 and 0.10 U L-1, respectively. The absorption of p-NP at 400 nm showed a good overlap with the excitation and emission of SQDs, leading to inner filter effect-based RSEW and fluorescence quenching of SQDs. This sensor platform was successfully applied in ALP sensing of serum samples as well as monitoring of ALP in cells. More importantly, this platform can serve as an example of using RSEW to detect ALP.
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Affiliation(s)
- Keke Ning
- College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
| | - Yao Fu
- College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
| | - Jianghong Wu
- College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
| | - Yujie Sun
- College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
| | - Ke Liu
- College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
| | - Kang Ye
- College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
| | - Jiaxin Liu
- College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
| | - Yuan Wu
- College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
| | - Jiangong Liang
- College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
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Sadeghi M, Balke J, Rafaluk-Mohr T, Alexiev U. Long-Distance Protonation-Conformation Coupling in Phytochrome Species. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238395. [PMID: 36500486 PMCID: PMC9737838 DOI: 10.3390/molecules27238395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/25/2022] [Accepted: 11/27/2022] [Indexed: 12/04/2022]
Abstract
Phytochromes are biological red/far-red light sensors found in many organisms. The connection between photoconversion and the cellular output signal involves light-mediated global structural changes in the interaction between the photosensory module (PAS-GAF-PHY, PGP) and the C-terminal transmitter (output) module. We recently showed a direct correlation of chromophore deprotonation with pH-dependent conformational changes in the various domains of the prototypical phytochrome Cph1 PGP. These results suggested that the transient phycocyanobilin (PCB) chromophore deprotonation is closely associated with a higher protein mobility both in proximal and distal protein sites, implying a causal relationship that might be important for the global large-scale protein rearrangements. Here, we investigate the prototypical biliverdin (BV)-binding phytochrome Agp1. The structural changes at various positions in Agp1 PGP were investigated as a function of pH using picosecond time-resolved fluorescence anisotropy and site-directed fluorescence labeling of cysteine variants of Agp1 PGP. We show that the direct correlation of chromophore deprotonation with pH-dependent conformational changes does not occur in Agp1. Together with the absence of long-range effects between the PHY domain and chromophore pKa, in contrast to the findings in Cph1, our results imply phytochrome species-specific correlations between transient chromophore deprotonation and intramolecular signal transduction.
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14
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QuasAr Odyssey: the origin of fluorescence and its voltage sensitivity in microbial rhodopsins. Nat Commun 2022; 13:5501. [PMID: 36127376 PMCID: PMC9489792 DOI: 10.1038/s41467-022-33084-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 08/26/2022] [Indexed: 11/29/2022] Open
Abstract
Rhodopsins had long been considered non-fluorescent until a peculiar voltage-sensitive fluorescence was reported for archaerhodopsin-3 (Arch3) derivatives. These proteins named QuasArs have been used for imaging membrane voltage changes in cell cultures and small animals. However due to the low fluorescence intensity, these constructs require use of much higher light intensity than other optogenetic tools. To develop the next generation of sensors, it is indispensable to first understand the molecular basis of the fluorescence and its modulation by the membrane voltage. Based on spectroscopic studies of fluorescent Arch3 derivatives, we propose a unique photo-reaction scheme with extended excited-state lifetimes and inefficient photoisomerization. Molecular dynamics simulations of Arch3, of the Arch3 fluorescent derivative Archon1, and of several its mutants have revealed different voltage-dependent changes of the hydrogen-bonding networks including the protonated retinal Schiff-base and adjacent residues. Experimental observations suggest that under negative voltage, these changes modulate retinal Schiff base deprotonation and promote a decrease in the populations of fluorescent species. Finally, we identified molecular constraints that further improve fluorescence quantum yield and voltage sensitivity. The authors present an in-depth investigation of excited state dynamics and molecular mechanism of the voltage sensing in microbial rhodopsins. Using a combination of spectroscopic investigations and molecular dynamics simulations, the study proposes the voltage-modulated deprotonation of the chromophore as the key event in the voltage sensing. Thus, molecular constraints that may further improve the fluorescence quantum yield and the voltage sensitivity are presented.
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15
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de Grip WJ, Ganapathy S. Rhodopsins: An Excitingly Versatile Protein Species for Research, Development and Creative Engineering. Front Chem 2022; 10:879609. [PMID: 35815212 PMCID: PMC9257189 DOI: 10.3389/fchem.2022.879609] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/16/2022] [Indexed: 01/17/2023] Open
Abstract
The first member and eponym of the rhodopsin family was identified in the 1930s as the visual pigment of the rod photoreceptor cell in the animal retina. It was found to be a membrane protein, owing its photosensitivity to the presence of a covalently bound chromophoric group. This group, derived from vitamin A, was appropriately dubbed retinal. In the 1970s a microbial counterpart of this species was discovered in an archaeon, being a membrane protein also harbouring retinal as a chromophore, and named bacteriorhodopsin. Since their discovery a photogenic panorama unfolded, where up to date new members and subspecies with a variety of light-driven functionality have been added to this family. The animal branch, meanwhile categorized as type-2 rhodopsins, turned out to form a large subclass in the superfamily of G protein-coupled receptors and are essential to multiple elements of light-dependent animal sensory physiology. The microbial branch, the type-1 rhodopsins, largely function as light-driven ion pumps or channels, but also contain sensory-active and enzyme-sustaining subspecies. In this review we will follow the development of this exciting membrane protein panorama in a representative number of highlights and will present a prospect of their extraordinary future potential.
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Affiliation(s)
- Willem J. de Grip
- Leiden Institute of Chemistry, Department of Biophysical Organic Chemistry, Leiden University, Leiden, Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Srividya Ganapathy
- Department of Imaging Physics, Delft University of Technology, Netherlands
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16
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The interaction studies of novel imine ligands and palladium(II) complexes with DNA and BSA for drug delivery application: the anti-cancer activity and molecular docking evaluation. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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17
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Nagano S, Sadeghi M, Balke J, Fleck M, Heckmann N, Psakis G, Alexiev U. Improved fluorescent phytochromes for in situ imaging. Sci Rep 2022; 12:5587. [PMID: 35379835 PMCID: PMC8980088 DOI: 10.1038/s41598-022-09169-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 03/14/2022] [Indexed: 12/18/2022] Open
Abstract
AbstractModern biology investigations on phytochromes as near-infrared fluorescent pigments pave the way for the development of new biosensors, as well as for optogenetics and in vivo imaging tools. Recently, near-infrared fluorescent proteins (NIR-FPs) engineered from biliverdin-binding bacteriophytochromes and cyanobacteriochromes, and from phycocyanobilin-binding cyanobacterial phytochromes have become promising probes for fluorescence microscopy and in vivo imaging. However, current NIR-FPs typically suffer from low fluorescence quantum yields and short fluorescence lifetimes. Here, we applied the rational approach of combining mutations known to enhance fluorescence in the cyanobacterial phytochrome Cph1 to derive a series of highly fluorescent variants with fluorescence quantum yield exceeding 15%. These variants were characterised by biochemical and spectroscopic methods, including time-resolved fluorescence spectroscopy. We show that these new NIR-FPs exhibit high fluorescence quantum yields and long fluorescence lifetimes, contributing to their bright fluorescence, and provide fluorescence lifetime imaging measurements in E.coli cells.
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18
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Walters S, Feeks JA, Huynh KT, Hunter JJ. Adaptive optics two-photon excited fluorescence lifetime imaging ophthalmoscopy of photoreceptors and retinal pigment epithelium in the living non-human primate eye. BIOMEDICAL OPTICS EXPRESS 2022; 13:389-407. [PMID: 35154879 PMCID: PMC8803039 DOI: 10.1364/boe.444550] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/02/2021] [Accepted: 12/02/2021] [Indexed: 05/18/2023]
Abstract
Fluorescence lifetime imaging has demonstrated promise as a quantitative measure of cell health. Adaptive optics two-photon excited fluorescence (TPEF) ophthalmoscopy enables excitation of intrinsic retinal fluorophores involved in cellular metabolism and the visual cycle, providing in vivo visualization of retinal structure and function at the cellular scale. Combining these technologies revealed that macaque cones had a significantly longer mean TPEF lifetime than rods at 730 nm excitation. At 900 nm excitation, macaque photoreceptors had a significantly longer mean TPEF lifetime than the retinal pigment epithelium layer. AOFLIO can measure the fluorescence lifetime of intrinsic retinal fluorophores on a cellular scale, revealing differences in lifetime between retinal cell classes.
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Affiliation(s)
- Sarah Walters
- The Institute of Optics, University of Rochester, Rochester, NY 14642, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14642, USA
- Currently with IDEX Health & Science, West Henrietta, NY 14586, USA
- These authors contributed equally
| | - James A. Feeks
- The Institute of Optics, University of Rochester, Rochester, NY 14642, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14642, USA
- Currently with IDEX Health & Science, West Henrietta, NY 14586, USA
- These authors contributed equally
| | - Khang T. Huynh
- Center for Visual Science, University of Rochester, Rochester, NY 14642, USA
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14642, USA
| | - Jennifer J. Hunter
- The Institute of Optics, University of Rochester, Rochester, NY 14642, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14642, USA
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14642, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14642, USA
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19
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Abstract
Research on type 1 rhodopsins spans now a history of 50 years. Originally, just archaeal ion pumps and sensors have been discovered. However, with modern genetic techniques and gene sequencing tools, more and more proteins were identified in all kingdoms of life. Spectroscopic and other biophysical studies revealed quite diverse functions. Ion pumps, sensors, and channels are imprinted in the same seven-helix transmembrane protein scaffold carrying a retinal prosthetic group. In this review, molecular biology methods are described, which enabled the elucidation of their function and structure leading to optogenetic applications.
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Affiliation(s)
- Martin Engelhard
- Department Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
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20
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Identification of small molecule allosteric modulators that act as enhancers/disrupters of rhodopsin oligomerization. J Biol Chem 2021; 297:101401. [PMID: 34774799 PMCID: PMC8665362 DOI: 10.1016/j.jbc.2021.101401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/01/2021] [Accepted: 11/04/2021] [Indexed: 11/27/2022] Open
Abstract
The elongated cilia of the outer segment of rod and cone photoreceptor cells can contain concentrations of visual pigments of up to 5 mM. The rod visual pigments, G protein–coupled receptors called rhodopsins, have a propensity to self-aggregate, a property conserved among many G protein–coupled receptors. However, the effect of rhodopsin oligomerization on G protein signaling in native cells is less clear. Here, we address this gap in knowledge by studying rod phototransduction. As the rod outer segment is known to adjust its size proportionally to overexpression or reduction of rhodopsin expression, genetic perturbation of rhodopsin cannot be used to resolve this question. Therefore, we turned to high-throughput screening of a diverse library of 50,000 small molecules and used a novel assay for the detection of rhodopsin dimerization. This screen identified nine small molecules that either disrupted or enhanced rhodopsin dimer contacts in vitro. In a subsequent cell-free binding study, we found that all nine compounds decreased intrinsic fluorescence without affecting the overall UV-visible spectrum of rhodopsin, supporting their actions as allosteric modulators. Furthermore, ex vivo electrophysiological recordings revealed that a disruptive, hit compound #7 significantly slowed down the light response kinetics of intact rods, whereas compound #1, an enhancing hit candidate, did not substantially affect the photoresponse kinetics but did cause a significant reduction in light sensitivity. This study provides a monitoring tool for future investigation of the rhodopsin signaling cascade and reports the discovery of new allosteric modulators of rhodopsin dimerization that can also alter rod photoreceptor physiology.
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21
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Shrirao AB, Schloss RS, Fritz Z, Shrirao MV, Rosen R, Yarmush ML. Autofluorescence of blood and its application in biomedical and clinical research. Biotechnol Bioeng 2021; 118:4550-4576. [PMID: 34487351 DOI: 10.1002/bit.27933] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/20/2021] [Accepted: 08/27/2021] [Indexed: 11/05/2022]
Abstract
Autofluorescence of blood has been explored as a label free approach for detection of cell types, as well as for diagnosis and detection of infection, cancer, and other diseases. Although blood autofluorescence is used to indicate the presence of several physiological abnormalities with high sensitivity, it often lacks disease specificity due to use of a limited number of fluorophores in the detection of several abnormal conditions. In addition, the measurement of autofluorescence is sensitive to the type of sample, sample preparation, and spectroscopy method used for the measurement. Therefore, while current blood autofluorescence detection approaches may not be suitable for primary clinical diagnosis, it certainly has tremendous potential in developing methods for large scale screening that can identify high risk groups for further diagnosis using highly specific diagnostic tests. This review discusses the source of blood autofluorescence, the role of spectroscopy methods, and various applications that have used autofluorescence of blood, to explore the potential of blood autofluorescence in biomedical research and clinical applications.
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Affiliation(s)
- Anil B Shrirao
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey, USA
| | - Rene S Schloss
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey, USA
| | - Zachary Fritz
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey, USA
| | - Mayur V Shrirao
- Department of pathology, Government Medical College, Nagpur, India
| | - Robert Rosen
- Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Martin L Yarmush
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey, USA
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22
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Martínez-Aldino IY, Villaseca-Murillo M, Morales-Jiménez J, Rivera-Chávez J. Absolute configuration and protein tyrosine phosphatase 1B inhibitory activity of xanthoepocin, a dimeric naphtopyrone from Penicillium sp. IQ-429. Bioorg Chem 2021; 115:105166. [PMID: 34384957 DOI: 10.1016/j.bioorg.2021.105166] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/27/2021] [Accepted: 07/08/2021] [Indexed: 12/19/2022]
Abstract
Protein tyrosine phosphatase 1B (PTP1B) is an active target for developing drugs to treat type II diabetes, obesity, and cancer. However, in the past, research programs targeting this enzyme focused on discovering inhibitors of truncated models (hPTP1B1-282, hPTP1B1-298, or hPTP1B1-321), losing valuable information about the ligands' mechanism of inhibition and selectivity. Nevertheless, finding an allosteric site in hPTP1B1-321, and the full-length (hPTP1B1-400) protein expression, have shifted the strategies to discover new PTP1B inhibitors. Accordingly, as part of a research program directed at finding non-competitive inhibitors of hPTP1B1-400 from Pezizomycotina, the extract of Penicillium sp. (IQ-429) was chemically investigated. This study led to xanthoepocin (1) isolation, which was elucidated by means of spectroscopic and spectrometric data. The absolute configuration of 1 was determined to be 7R8S9R7'R8'S9'R by comparing the theoretical and experimental ECD spectra and by GIAO-NMR DP4 + statistical analysis. Xanthoepocin (1) inhibited the phosphatase activity of hPTP1B1-400 (IC50 value of 8.8 ± 1.0 µM) in a mixed type fashion, with ki and αki values of 5.5 and 6.6 μM, respectively. Docking xanthoepocin (1) with a homologated model of hPTP1B1-400 indicated that it binds in a pocket different from the catalytic triad at the interface of the N and C-terminal domains. Molecular dynamics (MD) simulations showed that 1 locks the WPD loop of hPTP1B1-400 in a closed conformation, avoiding substrate binding, products release, and catalysis, suggesting an allosteric modulation triggered by large-scale conformational and dynamics changes. Intrinsic quenching fluorescence experiments indicated that 1 behaves like a static quencher of hPTP1B1-400 (KSV = 1.1 × 105 M-1), and corroborated that it binds to the enzyme with an affinity constant (ka) of 3.7 × 105 M-1. Finally, the drug-likeness and medicinal chemistry friendliness of 1 were predicted with SwissADME.
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Affiliation(s)
- Ingrid Y Martínez-Aldino
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria 04510, Ciudad de México, Mexico
| | - Martha Villaseca-Murillo
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria 04510, Ciudad de México, Mexico
| | - Jesús Morales-Jiménez
- CONACYT-Consorcio de Investigación, Innovación y Desarrollo para las Zonas Áridas (CIIDZA), Instituto Potosino de Investigación Científica y Tecnológica A. C., Camino a la Presa San José 2055, Lomas 4a sección, 78216 San Luis Potosí, Mexico.
| | - José Rivera-Chávez
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria 04510, Ciudad de México, Mexico.
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23
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Morozov VN, Kolyvanova MA, Dement'eva OV, Rudoy VM, Kuzmin VA. Comparison of quenching efficacy of SYBR Green I and PicoGreen fluorescence by ultrasmall gold nanoparticles in isotropic and liquid-crystalline DNA systems. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114751] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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24
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Schafer CT, Shumate A, Farrens DL. Novel fluorescent GPCR biosensor detects retinal equilibrium binding to opsin and active G protein and arrestin signaling conformations. J Biol Chem 2020; 295:17486-17496. [PMID: 33453993 DOI: 10.1074/jbc.ra120.014631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 09/25/2020] [Indexed: 01/14/2023] Open
Abstract
Rhodopsin is a canonical class A photosensitive G protein-coupled receptor (GPCR), yet relatively few pharmaceutical agents targeting this visual receptor have been identified, in part due to the unique characteristics of its light-sensitive, covalently bound retinal ligands. Rhodopsin becomes activated when light isomerizes 11-cis-retinal into an agonist, all-trans-retinal (ATR), which enables the receptor to activate its G protein. We have previously demonstrated that, despite being covalently bound, ATR can display properties of equilibrium binding, yet how this is accomplished is unknown. Here, we describe a new approach for both identifying compounds that can activate and attenuate rhodopsin and testing the hypothesis that opsin binds retinal in equilibrium. Our method uses opsin-based fluorescent sensors, which directly report the formation of active receptor conformations by detecting the binding of G protein or arrestin fragments that have been fused onto the receptor's C terminus. We show that these biosensors can be used to monitor equilibrium binding of the agonist, ATR, as well as the noncovalent binding of β-ionone, an antagonist for G protein activation. Finally, we use these novel biosensors to observe ATR release from an activated, unlabeled receptor and its subsequent transfer to the sensor in real time. Taken together, these data support the retinal equilibrium binding hypothesis. The approach we describe should prove directly translatable to other GPCRs, providing a new tool for ligand discovery and mutant characterization.
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Affiliation(s)
- Christopher T Schafer
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA
| | - Anthony Shumate
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA
| | - David L Farrens
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA.
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25
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Cho HJ, Park SJ, Jung WH, Cho Y, Ahn DJ, Lee YS, Kim S. Injectable Single-Component Peptide Depot: Autonomously Rechargeable Tumor Photosensitization for Repeated Photodynamic Therapy. ACS NANO 2020; 14:15793-15805. [PMID: 33175520 DOI: 10.1021/acsnano.0c06881] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The general practice of photodynamic therapy (PDT) comprises repeated multiple sessions, where photosensitizers are repeatedly administered prior to each operation of light irradiation. To address potential problems arising from the total overdose of photosensitizer by such repeated injections, we here introduce an internalizing RGD peptide (iRGD) derivative (Ppa-iRGDC-BK01) that self-aggregates into an injectable single-component supramolecular depot. Ppa-iRGDC-BK01 is designed as an in situ self-implantable photosensitizer so that it forms a depot by itself upon injection, and its molecular functions (cancer cell internalization and photosensitization) are activated by sustained release, tumor targeting, and tumor-selective proteolytic/reductive cleavage of the iRGD segment. The experimental and theoretical studies revealed that when exposed to body temperature, Ppa-iRGDC-BK01 undergoes thermally accelerated self-assembly to form a supramolecular depot through the hydrophobic interaction of the Ppa pendants and the reorganization of the interpeptide hydrogen bonding. It turned out that the self-aggregation of Ppa-iRGDC-BK01 into a depot exerts a multiple-quenching effect on the photosensitivity to effectively prevent nonspecific phototoxicity and protect it from photobleaching outside the tumor, while enabling autonomous tumor rephotosensitization by long sustained release, tumor accumulation, and intratumoral activation over time. We demonstrate that depot formation through a single peritumoral injection and subsequent quintuple laser irradiations at intervals resulted in complete eradication of the tumor. During the repeated PDT, depot-implanted normal tissues around the tumor exhibited no phototoxic damage under laser exposure. Our approach of single-component photosensitizing supramolecular depot, combined with a strategy of tumor-targeted therapeutic activation, would be a safer and more precise operation of PDT through a nonconventional protocol composed of one-time photosensitizer injection and multiple laser irradiations.
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Affiliation(s)
- Hong-Jun Cho
- Center for Theragnosis, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Sung-Jun Park
- Center for Theragnosis, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
- School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Woo Hyuk Jung
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Yuri Cho
- Center for Theragnosis, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea
| | - Dong June Ahn
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea
| | - Yoon-Sik Lee
- School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Sehoon Kim
- Center for Theragnosis, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea
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Adinarayana TVS, Mishra A, Singhal I, Koti Reddy DVR. Facile green synthesis of silicon nanoparticles from Equisetum arvense for fluorescence based detection of Fe(iii) ions. NANOSCALE ADVANCES 2020; 2:4125-4132. [PMID: 36132780 PMCID: PMC9418957 DOI: 10.1039/d0na00307g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/12/2020] [Indexed: 05/03/2023]
Abstract
Fluorescent silicon nanoparticles (SiNPs) might be one of the excellent candidates for use as optical markers in biological profiling and diagnostic applications. To exploit this perspective, they ought to be essentially synthesized from any green precursor rich in silicon. Stable dispersibility in water along with prolonged luminescence under different conditions is also desired. Moreover, one of the main challenges is to produce such optically (photoluminescence) stable and water-dispersible SiNPs. In our present work, we have reported the synthesis of a highly stable silicon nanoparticle aqueous suspension via a single-step microwave-assisted facile green route. Our as-prepared SiNPs exhibit inherent stable dispersibility, strong fluorescence, and photo-stable behavior. The experimental results demonstrate that the synthesized SiNPs are highly suitable for the detection of Fe(iii) ions. This optical sensing study opens a new avenue for use of SiNPs as a valuable optical probe in chemosensory applications. Our results provide a single-step methodology for the synthesis of highly stable SiNPs from a biological precursor, which can be used as a promising tool for various chemical and biological applications.
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Affiliation(s)
- T V S Adinarayana
- Department of Instrument Technology, Andhra University College of Engineering, Andhra University Andhra Pradesh India
| | - Ayushi Mishra
- School of Biotechnology, Jawaharlal Nehru University New Delhi India
| | - Ishu Singhal
- School of Biotechnology, Jawaharlal Nehru University New Delhi India
| | - D V Rama Koti Reddy
- Department of Instrument Technology, Andhra University College of Engineering, Andhra University Andhra Pradesh India
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27
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Penzkofer A, Silapetere A, Hegemann P. Absorption and Emission Spectroscopic Investigation of the Thermal Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor Archon2. Int J Mol Sci 2020; 21:ijms21186576. [PMID: 32911811 PMCID: PMC7555599 DOI: 10.3390/ijms21186576] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 08/28/2020] [Accepted: 09/01/2020] [Indexed: 01/12/2023] Open
Abstract
Archon2 is a fluorescent voltage sensor derived from Archaerhodopsin 3 (Arch) of Halorubrum sodomense using robotic multidimensional directed evolution approach. Here we report absorption and emission spectroscopic studies of Archon2 in Tris buffer at pH 8. Absorption cross-section spectra, fluorescence quantum distributions, fluorescence quantum yields, and fluorescence excitation spectra were determined. The thermal stability of Archon2 was studied by long-time attenuation coefficient measurements at room temperature (21 ± 1 °C) and at refrigerator temperature (3 ± 1 °C). The apparent melting temperature was determined by stepwise sample heating up and cooling down (obtained apparent melting temperature: 63 ± 3 °C). In the protein melting process protonated retinal Schiff base (PRSB) with absorption maximum at 586 nm converted to de-protonated retinal Schiff base (RSB) with absorption maximum at 380 nm. Storage of Archon2 at room temperature and refrigerator temperature caused absorption coefficient decrease because of partial protein clustering to aggregates at condensation nuclei and sedimentation. At room temperature an onset of light scattering was observed after two days because of the beginning of protein unfolding. During the period of observation (18 days at 21 °C, 22 days at 3 °C) no change of retinal isomer composition was observed indicating a high potential energy barrier of S0 ground-state isomerization.
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Affiliation(s)
- Alfons Penzkofer
- Fakultät für Physik, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
- Correspondence: ; Tel.: +49-941-943-2107
| | - Arita Silapetere
- Experimentelle Biophysik, Institut für Biologie, Humboldt Universität zu Berlin, Invalidenstraße 42, D-10115 Berlin, Germany; (A.S.); (P.H.)
| | - Peter Hegemann
- Experimentelle Biophysik, Institut für Biologie, Humboldt Universität zu Berlin, Invalidenstraße 42, D-10115 Berlin, Germany; (A.S.); (P.H.)
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28
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Sadeghi M, Balke J, Schneider C, Nagano S, Stellmacher J, Lochnit G, Lang C, Weise C, Hughes J, Alexiev U. Transient Deprotonation of the Chromophore Affects Protein Dynamics Proximal and Distal to the Linear Tetrapyrrole Chromophore in Phytochrome Cph1. Biochemistry 2020; 59:1051-1062. [PMID: 32069394 DOI: 10.1021/acs.biochem.9b00967] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phytochromes are biological red/far-red light sensors found in many organisms. Prototypical phytochromes, including Cph1 from the cyanobacterium Synechocystis 6803, act as photochemical switches that interconvert between stable red (Pr)- and metastable far-red (Pfr)-absorbing states induced by photoisomerization of the bilin chromophore. The connection between photoconversion and the cellular output signal involves light-mediated global structural changes in the interaction between the photosensory module (PAS-GAF-PHY) and the C-terminal transmitter (output) module, usually a histidine kinase, as in the case of Cph1. The chromophore deprotonates transiently during the Pr → Pfr photoconversion in association with extensive global structural changes required for signal transmission. Here, we performed equilibrium studies in the Pr state, involving pH titration of the linear tetrapyrrole chromophore in different Cph1 constructs, and measurement of pH-dependent structural changes at various positions in the protein using picosecond time-resolved fluorescence anisotropy. The fluorescent reporter group was attached at positions 371 (PHY domain), 305 (GAF domain), and 120 (PAS domain), as well as at sites in the PAS-GAF bidomain. We show direct correlation of chromophore deprotonation with pH-dependent conformational changes in the various domains. Our results suggest that chromophore deprotonation is closely associated with a higher protein mobility (conformational space) both in proximal and in distal protein sites, implying a causal relationship that might be important for the global large protein arrangements and thus intramolecular signal transduction.
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Affiliation(s)
- Maryam Sadeghi
- Freie Universität Berlin, Institut für Experimentalphysik, D-14195 Berlin, Germany
| | - Jens Balke
- Freie Universität Berlin, Institut für Experimentalphysik, D-14195 Berlin, Germany
| | - Constantin Schneider
- Freie Universität Berlin, Institut für Experimentalphysik, D-14195 Berlin, Germany
| | - Soshichiro Nagano
- Justus-Liebig-Universität, Institut für Pflanzenphysiologie, D-35390 Giessen, Germany
| | - Johannes Stellmacher
- Freie Universität Berlin, Institut für Experimentalphysik, D-14195 Berlin, Germany
| | - Günter Lochnit
- Justus-Liebig-Universität, Institut für Medizinische Biochemie, D-35390 Giessen, Germany
| | - Christina Lang
- Justus-Liebig-Universität, Institut für Pflanzenphysiologie, D-35390 Giessen, Germany
| | - Chris Weise
- Freie Universität Berlin, Institut für Chemie und Biochemie, D-14195 Berlin, Germany
| | - Jon Hughes
- Justus-Liebig-Universität, Institut für Pflanzenphysiologie, D-35390 Giessen, Germany
| | - Ulrike Alexiev
- Freie Universität Berlin, Institut für Experimentalphysik, D-14195 Berlin, Germany
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29
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Carvalho Bertozo L, Fernandes AJFC, Yoguim MI, Bolean M, Ciancaglini P, Ximenes VF. Entropy‐driven binding of octyl gallate in albumin: Failure in the application of temperature effect to distinguish dynamic and static fluorescence quenching. J Mol Recognit 2020; 33:e2840. [DOI: 10.1002/jmr.2840] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/25/2020] [Accepted: 02/10/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Luiza Carvalho Bertozo
- Department of Chemistry, Faculty of SciencesUNESP—São Paulo State University São Paulo Brazil
| | - Ana J. F. C. Fernandes
- Department of Chemistry, Faculty of SciencesUNESP—São Paulo State University São Paulo Brazil
| | - Maurício I. Yoguim
- Department of Chemistry, Faculty of SciencesUNESP—São Paulo State University São Paulo Brazil
| | - Maytê Bolean
- Department of Chemistry, Faculty of Philosophy, Sciences and Letters at Ribeirão PretoUniversity of São Paulo Ribeirão Preto SP Brazil
| | - Pietro Ciancaglini
- Department of Chemistry, Faculty of Philosophy, Sciences and Letters at Ribeirão PretoUniversity of São Paulo Ribeirão Preto SP Brazil
| | - Valdecir F. Ximenes
- Department of Chemistry, Faculty of SciencesUNESP—São Paulo State University São Paulo Brazil
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30
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Gakhar S, Risbud SH, Longo ML. Structure retention of silica gel-encapsulated bacteriorhodopsin in purple membrane and in lipid nanodiscs. Colloids Surf B Biointerfaces 2019; 186:110680. [PMID: 31835183 DOI: 10.1016/j.colsurfb.2019.110680] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/26/2019] [Indexed: 11/24/2022]
Abstract
The integral membrane protein, bacteriorhodopsin (BR) was encapsulated in sol-gel derived porous silica gel monoliths in native purple membrane (BR-PM) and synthetic lipid nanodisc (BR nanodisc) environments. BR nanodiscs were synthesized by solubilizing purple membrane in discoidal phospholipid bilayer stabilized by amphipathic Styrene-Maleic Acid (SMA) copolymer. UV-vis absorbance spectroscopy and dynamic-light scattering indicated the formation of BR monomers solubilized in lipid nanodiscs 10.2 ± 0.7 nm in average diameter. Fluorescence and absorbance spectroscopic techniques were utilized to probe conformational, environmental, and rotational changes associated with the tryptophan residues and the covalently-bound retinal moiety of BR upon entrapment in the silica matrix. We show that the immobilized BR in both membrane environments retained its bound retinal cofactor and the ability of the cofactor to undergo conformational changes upon light illumination necessary for BR's activity as a proton transporter. For purple membrane fragments, the results indicated that the local pH in the pores around BR after encapsulation was important for its stability at temperatures higher than 50 °C. Under the same buffering conditions, retinal was released from silica-encapsulated BR-PM and BR nanodiscs beginning at 80 °C (without a conformational change) and 50 °C (with a conformational change), respectively, reflecting differences in protein-protein (trimeric vs. monomeric) and protein-lipid interactions.
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Affiliation(s)
- Sukriti Gakhar
- Department of Chemical Engineering, University of California Davis, Davis, California, 95616, United States
| | - Subhash H Risbud
- Department of Materials Science and Engineering, University of California Davis, Davis, California, 95616, United States
| | - Marjorie L Longo
- Department of Chemical Engineering, University of California Davis, Davis, California, 95616, United States.
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31
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Suga M, Shimada A, Akita F, Shen JR, Tosha T, Sugimoto H. Time-resolved studies of metalloproteins using X-ray free electron laser radiation at SACLA. Biochim Biophys Acta Gen Subj 2019; 1864:129466. [PMID: 31678142 DOI: 10.1016/j.bbagen.2019.129466] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 10/02/2019] [Accepted: 10/04/2019] [Indexed: 01/12/2023]
Abstract
BACKGROUND The invention of the X-ray free-electron laser (XFEL) has provided unprecedented new opportunities for structural biology. The advantage of XFEL is an intense pulse of X-rays and a very short pulse duration (<10 fs) promising a damage-free and time-resolved crystallography approach. SCOPE OF REVIEW Recent time-resolved crystallographic analyses in XFEL facility SACLA are reviewed. Specifically, metalloproteins involved in the essential reactions of bioenergy conversion including photosystem II, cytochrome c oxidase and nitric oxide reductase are described. MAJOR CONCLUSIONS XFEL with pump-probe techniques successfully visualized the process of the reaction and the dynamics of a protein. Since the active center of metalloproteins is very sensitive to the X-ray radiation, damage-free structures obtained by XFEL are essential to draw mechanistic conclusions. Methods and tools for sample delivery and reaction initiation are key for successful measurement of the time-resolved data. GENERAL SIGNIFICANCE XFEL is at the center of approaches to gain insight into complex mechanism of structural dynamics and the reactions catalyzed by biological macromolecules. Further development has been carried out to expand the application of time-resolved X-ray crystallography. This article is part of a Special Issue entitled Novel measurement techniques for visualizing 'live' protein molecules.
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Affiliation(s)
- Michihiro Suga
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima Naka, Okayama 700-8530, Japan..
| | - Atsuhiro Shimada
- Graduate School of Applied Biological Sciences and Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan..
| | - Fusamichi Akita
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima Naka, Okayama 700-8530, Japan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima Naka, Okayama 700-8530, Japan
| | - Takehiko Tosha
- Synchrotron Radiation Life Science Instrumentation Team, RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
| | - Hiroshi Sugimoto
- Synchrotron Radiation Life Science Instrumentation Team, RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan..
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32
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Raghuraman H, Chatterjee S, Das A. Site-Directed Fluorescence Approaches for Dynamic Structural Biology of Membrane Peptides and Proteins. Front Mol Biosci 2019; 6:96. [PMID: 31608290 PMCID: PMC6774292 DOI: 10.3389/fmolb.2019.00096] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/11/2019] [Indexed: 12/31/2022] Open
Abstract
Membrane proteins mediate a number of cellular functions and are associated with several diseases and also play a crucial role in pathogenicity. Due to their importance in cellular structure and function, they are important drug targets for ~60% of drugs available in the market. Despite the technological advancement and recent successful outcomes in determining the high-resolution structural snapshot of membrane proteins, the mechanistic details underlining the complex functionalities of membrane proteins is least understood. This is largely due to lack of structural dynamics information pertaining to different functional states of membrane proteins in a membrane environment. Fluorescence spectroscopy is a widely used technique in the analysis of functionally-relevant structure and dynamics of membrane protein. This review is focused on various site-directed fluorescence (SDFL) approaches and their applications to explore structural information, conformational changes, hydration dynamics, and lipid-protein interactions of important classes of membrane proteins that include the pore-forming peptides/proteins, ion channels/transporters and G-protein coupled receptors.
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Affiliation(s)
- H. Raghuraman
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, Homi Bhabha National Institute, Kolkata, India
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33
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Ober K, Volz-Rakebrand P, Stellmacher J, Brodwolf R, Licha K, Haag R, Alexiev U. Expanding the Scope of Reporting Nanoparticles: Sensing of Lipid Phase Transitions and Nanoviscosities in Lipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11422-11434. [PMID: 31378067 DOI: 10.1021/acs.langmuir.9b01372] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Biological membrane fluidity and thus the local viscosity in lipid membranes are of vital importance for many life processes and implicated in various diseases. Here, we introduce a novel viscosity sensor design for lipid membranes based on a reporting nanoparticle, a sulfated dendritic polyglycerol (dPGS), conjugated to a fluorescent molecular rotor, indocarbocyanine (ICC). We show that dPGS-ICC provides high affinity to lipid bilayers, enabling viscosity sensing in the lipid tail region. The systematic characterization of viscosity- and temperature-dependent photoisomerization properties of ICC and dPGS-ICC allowed us to determine membrane viscosities in different model systems and in living cells using fluorescence lifetime imaging (FLIM). dPGS-ICC distinguishes between ordered lipids and the onset of membrane defects in small unilamellar single lipid vesicles and is highly sensitive in the fluid phase to small changes in viscosity introduced by cholesterol. In microscopy-based viscosity measurements of large multilamellar vesicles, we observed an order of magnitude more viscous environments by dPGS-ICC, lending support to the hypothesis of heterogeneous nanoviscosity environments even in single lipid bilayers. The existence of such complex viscosity structures could explain the large variation in the apparent membrane viscosity values found in the literature, depending on technique and probe, both for model membranes and live cells. In HeLa cells, a tumor-derived cell line, our nanoparticle-based viscosity sensor detects a membrane viscosity of ∼190 cP and is able to discriminate between cell membrane and intracellular vesicle localization. Thus, our results show the versatility of the dPGS-ICC nano-conjugate in physicochemical and biomedical applications by adding a new analytical functionality to its medical properties.
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Affiliation(s)
- Katja Ober
- Institut für Experimentalphysik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Pierre Volz-Rakebrand
- Institut für Experimentalphysik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Johannes Stellmacher
- Institut für Experimentalphysik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Robert Brodwolf
- Institut für Experimentalphysik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Kai Licha
- Mivenion GmbH , Robert-Koch-Platz 4 , 10115 Berlin , Germany
| | - Rainer Haag
- Institut für Chemie und Biochemie , Freie Universität Berlin , Takustraße 3 , 14195 Berlin , Germany
| | - Ulrike Alexiev
- Institut für Experimentalphysik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
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34
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Getter T, Gulati S, Zimmerman R, Chen Y, Vinberg F, Palczewski K. Stereospecific modulation of dimeric rhodopsin. FASEB J 2019; 33:9526-9539. [PMID: 31121099 PMCID: PMC6662988 DOI: 10.1096/fj.201900443rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 04/23/2019] [Indexed: 11/11/2022]
Abstract
The classic concept that GPCRs function as monomers has been challenged by the emerging evidence of GPCR dimerization and oligomerization. Rhodopsin (Rh) is the only GPCR whose native oligomeric arrangement was revealed by atomic force microscopy demonstrating that Rh exists as a dimer. However, the role of Rh dimerization in retinal physiology is currently unknown. In this study, we identified econazole and sulconazole, two small molecules that disrupt Rh dimer contacts, by implementing a cell-based high-throughput screening assay. Racemic mixtures of identified lead compounds were separated and tested for their stereospecific binding to Rh using UV-visible spectroscopy and intrinsic fluorescence of tryptophan (Trp) 265 after illumination. By following the changes in UV-visible spectra and Trp265 fluorescence in vitro, we found that binding of R-econazole modulates the formation of Meta III and quenches the intrinsic fluorescence of Trp265. In addition, electrophysiological ex vivo recording revealed that R-econazole slows photoresponse kinetics, whereas S-econazole decreased the sensitivity of rods without effecting the kinetics. Thus, this study contributes new methodology to identify compounds that disrupt the dimerization of GPCRs in general and validates the first active compounds that disrupt the Rh dimer specifically.-Getter, T., Gulati, S., Zimmerman, R., Chen, Y., Vinberg, F., Palczewski, K. Stereospecific modulation of dimeric rhodopsin.
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Affiliation(s)
- Tamar Getter
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California–Irvine, California, USA
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Sahil Gulati
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California–Irvine, California, USA
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Physiology and Biophysics, University of California–Irvine, Irvine, California, USA
| | - Remy Zimmerman
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California–Irvine, California, USA
| | - Yuanyuan Chen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Frans Vinberg
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Krzysztof Palczewski
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California–Irvine, California, USA
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Physiology and Biophysics, University of California–Irvine, Irvine, California, USA
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35
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Giliberti V, Polito R, Ritter E, Broser M, Hegemann P, Puskar L, Schade U, Zanetti-Polzi L, Daidone I, Corni S, Rusconi F, Biagioni P, Baldassarre L, Ortolani M. Tip-Enhanced Infrared Difference-Nanospectroscopy of the Proton Pump Activity of Bacteriorhodopsin in Single Purple Membrane Patches. NANO LETTERS 2019; 19:3104-3114. [PMID: 30950626 PMCID: PMC6745627 DOI: 10.1021/acs.nanolett.9b00512] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 04/02/2019] [Indexed: 05/21/2023]
Abstract
Photosensitive proteins embedded in the cell membrane (about 5 nm thickness) act as photoactivated proton pumps, ion gates, enzymes, or more generally, as initiators of stimuli for the cell activity. They are composed of a protein backbone and a covalently bound cofactor (e.g. the retinal chromophore in bacteriorhodopsin (BR), channelrhodopsin, and other opsins). The light-induced conformational changes of both the cofactor and the protein are at the basis of the physiological functions of photosensitive proteins. Despite the dramatic development of microscopy techniques, investigating conformational changes of proteins at the membrane monolayer level is still a big challenge. Techniques based on atomic force microscopy (AFM) can detect electric currents through protein monolayers and even molecular binding forces in single-protein molecules but not the conformational changes. For the latter, Fourier-transform infrared spectroscopy (FTIR) using difference-spectroscopy mode is typically employed, but it is performed on macroscopic liquid suspensions or thick films containing large amounts of purified photosensitive proteins. In this work, we develop AFM-assisted, tip-enhanced infrared difference-nanospectroscopy to investigate light-induced conformational changes of the bacteriorhodopsin mutant D96N in single submicrometric native purple membrane patches. We obtain a significant improvement compared with the signal-to-noise ratio of standard IR nanospectroscopy techniques by exploiting the field enhancement in the plasmonic nanogap that forms between a gold-coated AFM probe tip and an ultraflat gold surface, as further supported by electromagnetic and thermal simulations. IR difference-spectra in the 1450-1800 cm-1 range are recorded from individual patches as thin as 10 nm, with a diameter of less than 500 nm, well beyond the diffraction limit for FTIR microspectroscopy. We find clear spectroscopic evidence of a branching of the photocycle for BR molecules in direct contact with the gold surfaces, with equal amounts of proteins either following the standard proton-pump photocycle or being trapped in an intermediate state not directly contributing to light-induced proton transport. Our results are particularly relevant for BR-based optoelectronic and energy-harvesting devices, where BR molecular monolayers are put in contact with metal surfaces, and, more generally, for AFM-based IR spectroscopy studies of conformational changes of proteins embedded in intrinsically heterogeneous native cell membranes.
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Affiliation(s)
- Valeria Giliberti
- Istituto
Italiano di Tecnologia, Center for Life NanoScience, Viale Regina Elena 291, I-00161 Roma, Italy
- E-mail:
| | - Raffaella Polito
- Department
of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, I-00185 Roma, Italy
| | - Eglof Ritter
- Humboldt-Universität
zu Berlin, Institut für
Biologie, Invalidenstraße
42, D-10115 Berlin, Germany
| | - Matthias Broser
- Humboldt-Universität
zu Berlin, Institut für
Biologie, Invalidenstraße
42, D-10115 Berlin, Germany
| | - Peter Hegemann
- Humboldt-Universität
zu Berlin, Institut für
Biologie, Invalidenstraße
42, D-10115 Berlin, Germany
| | - Ljiljana Puskar
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - Ulrich Schade
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - Laura Zanetti-Polzi
- Department
of Physical and Chemical Sciences, University
of L’Aquila, Via Vetoio, I-67010 L’Aquila, Italy
| | - Isabella Daidone
- Department
of Physical and Chemical Sciences, University
of L’Aquila, Via Vetoio, I-67010 L’Aquila, Italy
| | - Stefano Corni
- Department
of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131 Padova, Italy
- CNR
Institute
of Nanoscience, Via Campi
213/A, I-41125 Modena, Italy
| | - Francesco Rusconi
- Dipartimento
di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Paolo Biagioni
- Dipartimento
di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Leonetta Baldassarre
- Department
of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, I-00185 Roma, Italy
| | - Michele Ortolani
- Istituto
Italiano di Tecnologia, Center for Life NanoScience, Viale Regina Elena 291, I-00161 Roma, Italy
- Department
of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, I-00185 Roma, Italy
- E-mail:
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36
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Boostani S, Hosseini SMH, Yousefi G, Riazi M, Tamaddon AM, Van der Meeren P. The stability of triphasic oil-in-water Pickering emulsions can be improved by physical modification of hordein- and secalin-based submicron particles. Food Hydrocoll 2019. [DOI: 10.1016/j.foodhyd.2018.11.035] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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37
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Yang Y, Zhang N, Sun Y, Li J, Zhao R, Zheng Z, Ding Y, Zhang X, Geng D, Sun Y. Multispectroscopic and molecular modeling studies on the interaction of bile acids with bovine serum albumin (BSA). J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2018.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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38
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Mittal S, Shukla D. Maximizing Kinetic Information Gain of Markov State Models for Optimal Design of Spectroscopy Experiments. J Phys Chem B 2018; 122:10793-10805. [DOI: 10.1021/acs.jpcb.8b07076] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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39
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Balke J, Volz P, Neumann F, Brodwolf R, Wolf A, Pischon H, Radbruch M, Mundhenk L, Gruber AD, Ma N, Alexiev U. Visualizing Oxidative Cellular Stress Induced by Nanoparticles in the Subcytotoxic Range Using Fluorescence Lifetime Imaging. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1800310. [PMID: 29726099 DOI: 10.1002/smll.201800310] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/16/2018] [Indexed: 06/08/2023]
Abstract
Nanoparticles hold a great promise in biomedical science. However, due to their unique physical and chemical properties they can lead to overproduction of intracellular reactive oxygen species (ROS). As an important mechanism of nanotoxicity, there is a great need for sensitive and high-throughput adaptable single-cell ROS detection methods. Here, fluorescence lifetime imaging microscopy (FLIM) is employed for single-cell ROS detection (FLIM-ROX) providing increased sensitivity and enabling high-throughput analysis in fixed and live cells. FLIM-ROX owes its sensitivity to the discrimination of autofluorescence from the unique fluorescence lifetime of the ROS reporter dye. The effect of subcytotoxic amounts of cationic gold nanoparticles in J774A.1 cells and primary human macrophages on ROS generation is investigated. FLIM-ROX measures very low ROS levels upon gold nanoparticle exposure, which is undetectable by the conventional method. It is demonstrated that cellular morphology changes, elevated senescence, and DNA damage link the resulting low-level oxidative stress to cellular adverse effects and thus nanotoxicity. Multiphoton FLIM-ROX enables the quantification of spatial ROS distribution in vivo, which is shown for skin tissue as a target for nanoparticle exposure. Thus, this innovative method allows identifying of low-level ROS in vitro and in vivo and, subsequently, promotes understanding of ROS-associated nanotoxicity.
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Affiliation(s)
- Jens Balke
- Department of Physics, Freie Universität Berlin, Arnimalllee 14, 14195, Berlin, Germany
| | - Pierre Volz
- Department of Physics, Freie Universität Berlin, Arnimalllee 14, 14195, Berlin, Germany
| | - Falko Neumann
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany
| | - Robert Brodwolf
- Department of Physics, Freie Universität Berlin, Arnimalllee 14, 14195, Berlin, Germany
- Helmholtz Virtual Institute-Multifunctional Biomaterials for Medicine, Helmholtz-Zentrum Geesthacht Kantstr. 55, 14513, Teltow, Germany
| | - Alexander Wolf
- Department of Physics, Freie Universität Berlin, Arnimalllee 14, 14195, Berlin, Germany
| | - Hannah Pischon
- Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertagstraße 15, 14163, Berlin, Germany
| | - Moritz Radbruch
- Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertagstraße 15, 14163, Berlin, Germany
| | - Lars Mundhenk
- Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertagstraße 15, 14163, Berlin, Germany
| | - Achim D Gruber
- Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertagstraße 15, 14163, Berlin, Germany
| | - Nan Ma
- Helmholtz-Zentrum Geesthacht (HZG), Institut für Biomaterialforschung Kantstr. 55, 14513, Teltow, Germany
| | - Ulrike Alexiev
- Department of Physics, Freie Universität Berlin, Arnimalllee 14, 14195, Berlin, Germany
- Helmholtz Virtual Institute-Multifunctional Biomaterials for Medicine, Helmholtz-Zentrum Geesthacht Kantstr. 55, 14513, Teltow, Germany
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40
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Rodríguez S, Silva ML, Benaím G, Bubis J. Phosphorylation-induced conformational changes of photoactivated rhodopsin probed by fluorescent labeling at Cys 140 and Cys 316. Biochimie 2018; 150:57-69. [PMID: 29730301 DOI: 10.1016/j.biochi.2018.04.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 04/29/2018] [Indexed: 11/28/2022]
Abstract
In order to monitor conformational changes following photoactivation and phosphorylation of bovine rhodopsin, the two reactive sulfhydryl groups at Cys140 and Cys316 were specifically labeled with the monobromobimane (mBBr) fluorophore. Although alterations in conformation after light exposure of rhodopsin were not detected by fluorescence excitation scans (300-450 nm) of the mBBr-labeled protein, the fluorescence signal was reduced ∼ 90% in samples containing photoactivated phosphorhodopsin. Predominant labeling at either Cys140 or Cys316 in light-activated and phosphorylated rhodopsin merely generated a decrease of ∼38% and 28%, respectively, in the fluorescence excitation intensity. Thus, neither mBBr-modified Cys140 nor mBBr-modified Cys316 were involved single-handedly in the remarkable fall seen on the signal following phosphorylation of the protein; rather, the incorporation of phosphate groups on the mBBr-labeled light-activated rhodopsin appeared to affect its fluorescence signal in a cooperative or synergistic manner. These findings demonstrated that the phosphorylation of specific hydroxyl groups at the carboxyl terminal tail of rhodopsin causes definite conformational changes in the three-dimensional fold of the protein. Apparently, amino acid residues that are buried in the interior of the inactive protein become accessible following illumination and phosphorylation of rhodopsin, quenching in turn the fluorescence excitation signal of mBBr-modified rhodopsin.
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Affiliation(s)
- Sheerly Rodríguez
- Departamento de Biología Celular, Universidad Simón Bolívar, Caracas, Venezuela; Escuela de Química, Facultad de Ciencias, Universidad Central de Venezuela, Caracas, Venezuela.
| | - May-Li Silva
- Instituto de Estudios Avanzados IDEA, Caracas, Venezuela.
| | - Gustavo Benaím
- Instituto de Estudios Avanzados IDEA, Caracas, Venezuela; Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela, Caracas, Venezuela.
| | - José Bubis
- Departamento de Biología Celular, Universidad Simón Bolívar, Caracas, Venezuela.
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41
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Edlich A, Volz P, Brodwolf R, Unbehauen M, Mundhenk L, Gruber AD, Hedtrich S, Haag R, Alexiev U, Kleuser B. Crosstalk between core-multishell nanocarriers for cutaneous drug delivery and antigen-presenting cells of the skin. Biomaterials 2018; 162:60-70. [PMID: 29438881 DOI: 10.1016/j.biomaterials.2018.01.058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/24/2018] [Accepted: 01/31/2018] [Indexed: 01/15/2023]
Abstract
Owing their unique chemical and physical properties core-multishell (CMS) nanocarriers are thought to underlie their exploitable biomedical use for a topical treatment of skin diseases. This highlights the need to consider not only the efficacy of CMS nanocarriers but also the potentially unpredictable and adverse consequences of their exposure thereto. As CMS nanocarriers are able to penetrate into viable layers of normal and stripped human skin ex vivo as well as in in vitro skin disease models the understanding of nanoparticle crosstalk with components of the immune system requires thorough investigation. Our studies highlight the biocompatible properties of CMS nanocarriers on Langerhans cells of the skin as they did neither induce cytotoxicity and genotoxicity nor cause reactive oxygen species (ROS) or an immunological response. Nevertheless, CMS nanocarriers were efficiently taken up by Langerhans cells via divergent endocytic pathways. Bioimaging of CMS nanocarriers by fluorescence lifetime imaging microscopy (FLIM) and flow cytometry indicated not only a localization within the lysosomes but also an energy-dependent exocytosis of unmodified CMS nanocarriers into the extracellular environment.
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Affiliation(s)
- Alexander Edlich
- Institute of Nutritional Science, University of Potsdam, Potsdam, Germany
| | - Pierre Volz
- Institute of Experimental Physics, Freie Universität Berlin, Berlin, Germany
| | - Robert Brodwolf
- Institute of Experimental Physics, Freie Universität Berlin, Berlin, Germany
| | - Michael Unbehauen
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Lars Mundhenk
- Institute of Veterinary Pathology, Freie Universität Berlin, Berlin, Germany
| | - Achim D Gruber
- Institute of Veterinary Pathology, Freie Universität Berlin, Berlin, Germany
| | - Sarah Hedtrich
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Rainer Haag
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Ulrike Alexiev
- Institute of Experimental Physics, Freie Universität Berlin, Berlin, Germany.
| | - Burkhard Kleuser
- Institute of Nutritional Science, University of Potsdam, Potsdam, Germany.
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42
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Volz P, Brodwolf R, Zoschke C, Haag R, Schäfer-Korting M, Alexiev U. White-Light Supercontinuum Laser-Based Multiple Wavelength Excitation for TCSPC-FLIM of Cutaneous Nanocarrier Uptake. ACTA ACUST UNITED AC 2018. [DOI: 10.1515/zpch-2017-1050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
We report here on a custom-built time-correlated single photon-counting (TCSPC)-based fluorescence lifetime imaging microscopy (FLIM) setup with a continuously tunable white-light supercontinuum laser combined with acousto-optical tunable filters (AOTF) as an excitation source for simultaneous excitation of multiple spectrally separated fluorophores. We characterized the wavelength dependence of the white-light supercontinuum laser pulse properties and demonstrated the performance of the FLIM setup, aiming to show the experimental setup in depth together with a biomedical application. We herein summarize the physical-technical parameters as well as our approach to map the skin uptake of nanocarriers using FLIM with a resolution compared to spectroscopy. As an example, we focus on the penetration study of indocarbocyanine-labeled dendritic core-multishell nanocarriers (CMS-ICC) into reconstructed human epidermis. Unique fluorescence lifetime signatures of indocarbocyanine-labeled nanocarriers indicate nanocarrier-tissue interactions within reconstructed human epidermis, bringing FLIM close to spectroscopic analysis.
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Affiliation(s)
- Pierre Volz
- Institute of Experimental Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Robert Brodwolf
- Institute of Experimental Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
- Helmholtz Virtual Institute – Multifunctional Biomaterials for Medicine, Helmholtz-Zentrum Geesthacht , Kantstr. 55 , 14513 Teltow , Germany
| | - Christian Zoschke
- Institute of Pharmacy (Pharmacology and Toxicology) , Freie Universität Berlin , Königin-Luise-Str. 2+4 , 14195 Berlin , Germany
| | - Rainer Haag
- Helmholtz Virtual Institute – Multifunctional Biomaterials for Medicine, Helmholtz-Zentrum Geesthacht , Kantstr. 55 , 14513 Teltow , Germany
- Institute of Chemistry and Biochemistry , Freie Universität Berlin , Takustr. 3 , 14195 Berlin , Germany
| | - Monika Schäfer-Korting
- Helmholtz Virtual Institute – Multifunctional Biomaterials for Medicine, Helmholtz-Zentrum Geesthacht , Kantstr. 55 , 14513 Teltow , Germany
- Institute of Pharmacy (Pharmacology and Toxicology) , Freie Universität Berlin , Königin-Luise-Str. 2+4 , 14195 Berlin , Germany
| | - Ulrike Alexiev
- Institute of Experimental Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
- Helmholtz Virtual Institute – Multifunctional Biomaterials for Medicine, Helmholtz-Zentrum Geesthacht , Kantstr. 55 , 14513 Teltow , Germany
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43
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Volz P, Schilrreff P, Brodwolf R, Wolff C, Stellmacher J, Balke J, Morilla MJ, Zoschke C, Schäfer-Korting M, Alexiev U. Pitfalls in using fluorescence tagging of nanomaterials: tecto-dendrimers in skin tissue as investigated by Cluster-FLIM. Ann N Y Acad Sci 2017; 1405:202-214. [DOI: 10.1111/nyas.13473] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 08/21/2017] [Accepted: 08/24/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Pierre Volz
- Institute of Experimental Physics; Freie Universität Berlin; Berlin Germany
| | - Priscila Schilrreff
- Nanomedicine Research Program (Departamento de Ciencia y Tecnologia); Universidad Nacional de Quilmes; Buenos Aires Argentina
| | - Robert Brodwolf
- Institute of Experimental Physics; Freie Universität Berlin; Berlin Germany
| | - Christopher Wolff
- Institute for Pharmacy (Pharmacology and Toxicology); Freie Universität Berlin; Berlin Germany
| | | | - Jens Balke
- Institute of Experimental Physics; Freie Universität Berlin; Berlin Germany
| | - Maria J. Morilla
- Nanomedicine Research Program (Departamento de Ciencia y Tecnologia); Universidad Nacional de Quilmes; Buenos Aires Argentina
| | - Christian Zoschke
- Institute for Pharmacy (Pharmacology and Toxicology); Freie Universität Berlin; Berlin Germany
| | - Monika Schäfer-Korting
- Institute for Pharmacy (Pharmacology and Toxicology); Freie Universität Berlin; Berlin Germany
| | - Ulrike Alexiev
- Institute of Experimental Physics; Freie Universität Berlin; Berlin Germany
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44
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Dysli C, Wolf S, Berezin MY, Sauer L, Hammer M, Zinkernagel MS. Fluorescence lifetime imaging ophthalmoscopy. Prog Retin Eye Res 2017; 60:120-143. [PMID: 28673870 PMCID: PMC7396320 DOI: 10.1016/j.preteyeres.2017.06.005] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/19/2017] [Accepted: 06/29/2017] [Indexed: 12/17/2022]
Abstract
Imaging techniques based on retinal autofluorescence have found broad applications in ophthalmology because they are extremely sensitive and noninvasive. Conventional fundus autofluorescence imaging measures fluorescence intensity of endogenous retinal fluorophores. It mainly derives its signal from lipofuscin at the level of the retinal pigment epithelium. Fundus autofluorescence, however, can not only be characterized by the spatial distribution of the fluorescence intensity or emission spectrum, but also by a characteristic fluorescence lifetime function. The fluorescence lifetime is the average amount of time a fluorophore remains in the excited state following excitation. Fluorescence lifetime imaging ophthalmoscopy (FLIO) is an emerging imaging modality for in vivo measurement of lifetimes of endogenous retinal fluorophores. Recent reports in this field have contributed to our understanding of the pathophysiology of various macular and retinal diseases. Within this review, the basic concept of fluorescence lifetime imaging is provided. It includes technical background information and correlation with in vitro measurements of individual retinal metabolites. In a second part, clinical applications of fluorescence lifetime imaging and fluorescence lifetime features of selected retinal diseases such as Stargardt disease, age-related macular degeneration, choroideremia, central serous chorioretinopathy, macular holes, diabetic retinopathy, and retinal artery occlusion are discussed. Potential areas of use for fluorescence lifetime imaging ophthalmoscopy will be outlined at the end of this review.
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Affiliation(s)
- Chantal Dysli
- Department of Ophthalmology and Department of Clinical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Sebastian Wolf
- Department of Ophthalmology and Department of Clinical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Mikhail Y Berezin
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Lydia Sauer
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Martin Hammer
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Martin S Zinkernagel
- Department of Ophthalmology and Department of Clinical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland.
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45
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Recent advances in biophysical studies of rhodopsins - Oligomerization, folding, and structure. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1512-1521. [PMID: 28844743 DOI: 10.1016/j.bbapap.2017.08.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 08/06/2017] [Accepted: 08/11/2017] [Indexed: 12/19/2022]
Abstract
Retinal-binding proteins, mainly known as rhodopsins, function as photosensors and ion transporters in a wide range of organisms. From halobacterial light-driven proton pump, bacteriorhodopsin, to bovine photoreceptor, visual rhodopsin, they have served as prototypical α-helical membrane proteins in a large number of biophysical studies and aided in the development of many cutting-edge techniques of structural biology and biospectroscopy. In the last decade, microbial and animal rhodopsin families have expanded significantly, bringing into play a number of new interesting structures and functions. In this review, we will discuss recent advances in biophysical approaches to retinal-binding proteins, primarily microbial rhodopsins, including those in optical spectroscopy, X-ray crystallography, nuclear magnetic resonance, and electron paramagnetic resonance, as applied to such fundamental biological aspects as protein oligomerization, folding, and structure.
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46
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Bailes HJ, Milosavljevic N, Zhuang LY, Gerrard EJ, Nishiguchi T, Ozawa T, Lucas RJ. Optogenetic interrogation reveals separable G-protein-dependent and -independent signalling linking G-protein-coupled receptors to the circadian oscillator. BMC Biol 2017; 15:40. [PMID: 28506231 PMCID: PMC5430609 DOI: 10.1186/s12915-017-0380-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/26/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Endogenous circadian oscillators distributed across the mammalian body are synchronised among themselves and with external time via a variety of signalling molecules, some of which interact with G-protein-coupled receptors (GPCRs). GPCRs can regulate cell physiology via pathways originating with heterotrimeric G-proteins or β-arrestins. We applied an optogenetic approach to determine the contribution of these two signalling modes on circadian phase. RESULTS We employed a photopigment (JellyOp) that activates Gαs signalling with better selectivity and higher sensitivity than available alternatives, and a point mutant of this pigment (F112A) biased towards β-arrestin signalling. When expressed in fibroblasts, both native JellyOp and the F112A arrestin-biased mutant drove light-dependent phase resetting in the circadian clock. Shifts induced by the two opsins differed in their circadian phase dependence and the degree to which they were associated with clock gene induction. CONCLUSIONS Our data imply separable G-protein and arrestin inputs to the mammalian circadian clock and establish a pair of optogenetic tools suitable for manipulating Gαs- and β-arrestin-biased signalling in live cells.
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Affiliation(s)
- Helena J Bailes
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Nina Milosavljevic
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
| | - Ling-Yu Zhuang
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Elliot J Gerrard
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | | | - Takeaki Ozawa
- Department of Chemistry, The University of Tokyo, Tokyo, Japan
| | - Robert J Lucas
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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47
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Boreham A, Brodwolf R, Walker K, Haag R, Alexiev U. Time-Resolved Fluorescence Spectroscopy and Fluorescence Lifetime Imaging Microscopy for Characterization of Dendritic Polymer Nanoparticles and Applications in Nanomedicine. Molecules 2016; 22:molecules22010017. [PMID: 28029135 PMCID: PMC6155873 DOI: 10.3390/molecules22010017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 12/16/2016] [Accepted: 12/16/2016] [Indexed: 12/11/2022] Open
Abstract
The emerging field of nanomedicine provides new approaches for the diagnosis and treatment of diseases, for symptom relief and for monitoring of disease progression. One route of realizing this approach is through carefully constructed nanoparticles. Due to the small size inherent to the nanoparticles a proper characterization is not trivial. This review highlights the application of time-resolved fluorescence spectroscopy and fluorescence lifetime imaging microscopy (FLIM) for the analysis of nanoparticles, covering aspects ranging from molecular properties to particle detection in tissue samples. The latter technique is particularly important as FLIM allows for distinguishing of target molecules from the autofluorescent background and, due to the environmental sensitivity of the fluorescence lifetime, also offers insights into the local environment of the nanoparticle or its interactions with other biomolecules. Thus, these techniques offer highly suitable tools in the fields of particle development, such as organic chemistry, and in the fields of particle application, such as in experimental dermatology or pharmaceutical research.
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Affiliation(s)
- Alexander Boreham
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
| | - Robert Brodwolf
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
- Helmholtz Virtual Institute-Multifunctional Biomaterials for Medicine, Helmholtz-Zentrum Geesthacht, Kantstr. 55, 14513 Teltow, Germany.
| | - Karolina Walker
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany.
| | - Rainer Haag
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany.
- Helmholtz Virtual Institute-Multifunctional Biomaterials for Medicine, Helmholtz-Zentrum Geesthacht, Kantstr. 55, 14513 Teltow, Germany.
| | - Ulrike Alexiev
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
- Helmholtz Virtual Institute-Multifunctional Biomaterials for Medicine, Helmholtz-Zentrum Geesthacht, Kantstr. 55, 14513 Teltow, Germany.
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48
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Siriwardana K, Nettles CB, Vithanage BC, Zhou Y, Zou S, Zhang D. On-Resonance Fluorescence, Resonance Rayleigh Scattering, and Ratiometric Resonance Synchronous Spectroscopy of Molecular- and Quantum Dot-Fluorophores. Anal Chem 2016; 88:9199-206. [DOI: 10.1021/acs.analchem.6b02420] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Kumudu Siriwardana
- Department
of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Charles B. Nettles
- Department
of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Buddhini C.N. Vithanage
- Department
of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Yadong Zhou
- Department
of Chemistry, University of Central Florida, Orlando, Florida 32816, United States
| | - Shengli Zou
- Department
of Chemistry, University of Central Florida, Orlando, Florida 32816, United States
| | - Dongmao Zhang
- Department
of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
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49
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Richter C, Schneider C, Quick MT, Volz P, Mahrwald R, Hughes J, Dick B, Alexiev U, Ernsting NP. Dual-fluorescence pH probe for bio-labelling. Phys Chem Chem Phys 2016; 17:30590-7. [PMID: 26524563 DOI: 10.1039/c5cp05454k] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Although seminaphtorhodafluor (SNARF) dyes are already widely used to measure pH in cells and at biofilms, their synthesis has low yield and results in an unspecific position of a carboxy-group. The separation of 5'- and 6'-carboxy-SNARF reveals a pKa difference of 0.15, calling into question pH measurements with the (commercially available) mixture. Here we replace the bulky external dicarboxyphenyl ring with a propionate group and evaluate the spectral properties of the new derivative. Proceeding to the ethyl-iodoacetamide, covalent linkage to cysteine protein sites is achieved efficiently as shown with a cyanobacterial phytochrome, extending the scarce application of SNARF in bio-labelling in the current literature. Application in fluorescence lifetime imaging is demonstrated both with the lifetime-based and ratiometric-yield method.
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Affiliation(s)
- C Richter
- Department of Chemistry, Humboldt-Universität zu Berlin, 12489 Berlin, Germany.
| | - C Schneider
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany.
| | - M T Quick
- Department of Chemistry, Humboldt-Universität zu Berlin, 12489 Berlin, Germany.
| | - P Volz
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany.
| | - R Mahrwald
- Department of Chemistry, Humboldt-Universität zu Berlin, 12489 Berlin, Germany.
| | - J Hughes
- Institute for Plantphysiology, Justus-Liebig Universität, 35390 Giessen, Germany
| | - B Dick
- Institute for Physical and Theoretical Chemistry, Universität Regensburg, 93053 Regensburg, Germany
| | - U Alexiev
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany.
| | - N P Ernsting
- Department of Chemistry, Humboldt-Universität zu Berlin, 12489 Berlin, Germany.
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50
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Tian H, Fürstenberg A, Huber T. Labeling and Single-Molecule Methods To Monitor G Protein-Coupled Receptor Dynamics. Chem Rev 2016; 117:186-245. [DOI: 10.1021/acs.chemrev.6b00084] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- He Tian
- Laboratory of Chemical Biology
and Signal Transduction, The Rockefeller University, 1230 York
Avenue, New York, New York 10065, United States
| | - Alexandre Fürstenberg
- Laboratory of Chemical Biology
and Signal Transduction, The Rockefeller University, 1230 York
Avenue, New York, New York 10065, United States
| | - Thomas Huber
- Laboratory of Chemical Biology
and Signal Transduction, The Rockefeller University, 1230 York
Avenue, New York, New York 10065, United States
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