DOCSLIB.ORG

Reflectance and Fluorescence Spectroscopies in Photodynamic

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Reflectance and Fluorescence Spectroscopies in Photodynamic Reflectance and Fluorescence Spectroscopies in Photodynamic Therapy by Jarod C. Finlay Submitted in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Supervised by Professor Thomas H. Foster Department of Physics and Astronomy The College Arts and Sciences University of Rochester Rochester, New York 2003 To Leah iii Curriculum Vitae The author was born in Bryn Mawr, Pennsylvania, in 1975 and received his early education in the Pennsylvania towns of Phoenixville and Montoursville. During his junior year of high school, Finlay moved to Exeter, Pennsylvania where he enrolled in Exeter Township Senior High School. Here, he was first introduced to physics by his teacher Mr. Arthur Murray, whose encouragement of curiosity and inquisitiveness were more valuable than any lesson on Newton’s laws, and to higher mathematics by Mr. Robert Dahl, whose sense of humor made learning integral calculus an enjoyable experience. In his final year of high school, Finlay met Leah Janowsky, the woman he would later marry. After graduating high school in 1993, Finlay was accepted to Alfred University in Alfred, New York, with a National Merit Scholarship which allowed him the financial freedom to spend the next four years studying physics, mathematics, ce- ramic arts, and various humanities. His education in physics was supplemented by summer research projects at the Maria Mitchell Observatory and the University of Central Florida, both under the auspices of the National Science Foundation’s Research Experience for Undergraduates (REU) program, and by research con- ducted at Alfred under the tutelage of Professor David DeGraff. Finlay graduated CURRICULUM VITAE iv in the Spring of 1997 and was accepted to the graduate program in Physics at the University of Rochester with a Graduate Assistance in Areas of National Need (GAANN) Fellowship. During the following summer, he and Leah were married and started their life together in Rochester. After the requisite year of teaching assistantships and classes, Finlay took advantage of the opportunity to teach a summer undergraduate physics class, earning a Certificate in College Teaching and learning as much about teaching as his students did about physics. Finlay received his Master of Arts degree in Physics from the University of Rochester in 1999. Despite early intentions to study astrophysics, Finlay quickly developed an interest in biological physics and in the biomedical optics work being done in the laboratory of Professor Thomas Foster. In the summer of 1998, Finlay joined Foster’s research group and spent the next four years studying fluorescence spec- troscopy, sensitizer photobleaching and reflectance spectroscopy in the context of photodynamic therapy. In February of 2003, Finlay took up residence in Philadelphia as an Instructor in Physics in the Radiation Oncology Department at the University of Pennsyl- vania. This position gave him the opportunity to pursue his interest in photo- dynamic therapy research while gaining experience in the clinical applications of radiation therapy. The final stages of the writing of this thesis were completed during his initial months in Philadelphia. CURRICULUM VITAE v Publications J.C. Finlay and T.H. Foster, Method for the simultaneous recovery of tis- sue absorption and fluorophore concentration from fluorescence spectroscopy, Manuscript in preparation. J.C. Finlay and T.H. Foster, Quantitative single source-detector separation diffuse reflectance spectroscopy, Manuscript in preparation. J.C. Finlay, S. Mitra, and T.H. Foster, Photobleaching kinetics of Photofrin in vivo and in multicell tumor spheroids indicate multiple simultaneous bleaching mechanisms, Manuscript in preparation. J.C. Finlay, S. Mitra, and T.H. Foster, In vivo mTHPC photobleaching in normal rat skin exhibits unique irradiance-dependent features, Photochem. Pho- tobiol. 75;3 pp 282-288 (2002) S. Mitra, J.C. Finlay, D. McNeil, D.L. Conover, and T.H. Foster, Photochem- ical oxygen consumption, oxygen evolution and spectral changes during UVA ir- radiation of EMT6 spheroids, Photochem. Photobiol. 73;6 pp 703-708 (2001) J.C. Finlay, D.L. Conover, E.L Hull, and T.H. Foster, Porphyrin bleaching and PDT-induced spectral changes are irradiance dependent in ALA-sensitized normal rat skin in vivo, Photochem. Photobiol. 73;1 pp 54-63 (2001) Presentations J.C. Finlay, S. Mitra and T.H. Foster, Irradiance-dependent photobleaching and photoproduct accumulation during Photofrin-, mTHPC- and ALA-PDT in vivo: A comparative study, 30th Annual Meeting, American Society for Photobi- ology, July 13-17, 2002 Quebec City, Canada, Book of Abstracts, p 92 J.C. Finlay and T.H. Foster, Variance-optimized Monte Carlo routine for fluo- rescence and reflectance of turbid samples, 29th Annual Meeting, American Society for Photobiology, July 7-12, 2001, Chicago, IL, Book of Abstracts, p 76 S. Mitra, J.C. Finlay, D. McNeil, D.L. Conover and T.H. Foster, Photochemical oxygen consumption, oxygen evolution and spectral changes during UVA irradia- tion of EMT6 spheroids, 29th Annual Meeting, American Society for Photobiology, July 7-12, 2001, Chicago, IL, Book of Abstracts, p 82 CURRICULUM VITAE vi J.C. Finlay and T.H. Foster, Irradiance dependence of the fluorescence spec- trum of rat skin following ALA-sensitized PDT in vivo, 13th International Congress on Photobiology, July 1-6, 2000, San Francisco, CA, Book of Abstracts, p 55 S. Mitra, J.C. Finlay and T.H. Foster, Photobleaching of mTHPC during photodynamic therapy of multicell tumor spheroids and of normal rat skin, 13th International Congress on Photobiology, July 1-6, 2000, San Francisco, CA, Book of Abstracts, p 59 T.H. Foster, J.C. Finlay, D.L. Conover and E.L Hull, Sensitizer photobleaching and dosimetry, SPIE Bios ’99, Optical Methods for Tumor Treatment and Detec- tion: Mechanisms and Techniques in Photodynamic Therapy VII, January 23-29, 1999, Book of Abstracts, p 42 J.C. Finlay and T.H. Foster, Fluorescence and reflectance spectroscopy of PpIX-sensitized skin during PDT, 8th Congress, European Society for Photobiol- ogy, September 3-8, 1999, Granada, Spain, Book of Abstracts, p 88 vii Acknowledgments The thesis you hold in your hands is the product of several years of effort, none of which would have been possible without the help and support of a large number of people in the academic community and outside of it. I wish to thank my advisor, Professor Thomas Foster, for providing guidance on all aspects of my graduate work, from research methods and scientific writing to career direction and professional conduct. During my time in his laboratory, I have been exposed to a wide variety of research problems and experimental methods as well as being encouraged to develop and pursue my own interests. His advice, constructive criticism, and careful proofreading have been invaluable in the development of this thesis. Many of the experiments which contributed to this thesis would have been difficult or impossible without the technical expertise and inventiveness of David Conover, who built the majority of the experimental equipment described here. His diligence in tracking down and eliminating sources of noise, his frequent as- sistant with experiments and his meticulous documentation of instrument and experiment design are all greatly appreciated. I also whish to acknowledge many fruitful discussions, frequent experimental Acknowledgements viii assistance and occasional coauthorship with my fellow graduate students, Edward Hull, Soumya Mitra, Chad Bigelow and William Cottrell. The photobleaching studies described in chapter 3 benefitted from a great deal of help from Soumya and from Ed, who introduced me to much of the instrumentation and experiment design that formed the basis of my future experiments. Soumya and Chad taught me the fundamentals of cell culture and helped me develop the tumor model used in chapters 4 and 5. Jim Havens and Scott Gibson have been a great help in teaching me basic animal handling and sensitizer preparation. Scott A. Gerber, Amit Lugade, and James Moran, students in the laboratory of Dr. Edith Lord, were very generous with their time and expertise in helping me to develop the EMT-6 tumors used in the animal experiments described in chapters 4 and 5. Dr. William Herk- stroeter in the Chemistry department has been very generous with access to his calibrated fluorimeter, which I used extensively for calibration of my experimental equipment. Dr. Stephen Hahn of the University of Pennsylvania has generously provided the Photofrin R used in experiments described in chapter 3. My research at the University of Rochester has been supported by National Institutes of Health grants CA68409 and CA36856 awarded by the National Cancer Institute. The final stages of thesis writing benefited greatly from the time I spent work- ing on it while employed at the University of Pennsylvania. My employers’ will- ingness to accommodate it was very helpful. Last but in no way least, I owe a great debt of gratitude to my family and to my wife Leah, whose emotional and financial support have made my completion of this work possible, and whose love and patience has played a major part in maintaining Acknowledgements ix my sanity and happiness throughout its completion. Leah is a constant source of motivation and inspiration. x Abstract In vivo fluorescence spectroscopy during photodynamic therapy (PDT) has the potential to provide information on the distribution and degradation of sensitizers, the formation of fluorescent photoproducts and changes in tissue autofluorescence
Load more

Recommended publications
  • The Green Fluorescent Protein
    P1: rpk/plb P2: rpk April 30, 1998 11:6 Annual Reviews AR057-17 Annu. Rev. Biochem. 1998. 67:509–44 Copyright c 1998 by Annual Reviews. All rights reserved THE GREEN FLUORESCENT PROTEIN Roger Y. Tsien Howard Hughes Medical Institute; University of California, San Diego; La Jolla, CA 92093-0647 KEY WORDS: Aequorea, mutants, chromophore, bioluminescence, GFP ABSTRACT In just three years, the green fluorescent protein (GFP) from the jellyfish Aequorea victoria has vaulted from obscurity to become one of the most widely studied and exploited proteins in biochemistry and cell biology. Its amazing ability to generate a highly visible, efficiently emitting internal fluorophore is both intrin- sically fascinating and tremendously valuable. High-resolution crystal structures of GFP offer unprecedented opportunities to understand and manipulate the rela- tion between protein structure and spectroscopic function. GFP has become well established as a marker of gene expression and protein targeting in intact cells and organisms. Mutagenesis and engineering of GFP into chimeric proteins are opening new vistas in physiological indicators, biosensors, and photochemical memories. CONTENTS NATURAL AND SCIENTIFIC HISTORY OF GFP .................................510 Discovery and Major Milestones .............................................510 Occurrence, Relation to Bioluminescence, and Comparison with Other Fluorescent Proteins .....................................511 PRIMARY, SECONDARY, TERTIARY, AND QUATERNARY STRUCTURE ...........512 Primary Sequence from
    [Show full text]
  • Microenvironment-Triggered Dual-Activation of a Photosensitizer
    www.nature.com/scientificreports OPEN Microenvironment‑triggered dual‑activation of a photosensitizer‑ fuorophore conjugate for tumor specifc imaging and photodynamic therapy Chang Wang1, Shengdan Wang1, Yuan Wang1, Honghai Wu1, Kun Bao2, Rong Sheng1* & Xin Li1* Photodynamic therapy is attracting increasing attention, but how to increase its tumor‑specifcity remains a daunting challenge. Herein we report a theranostic probe (azo‑pDT) that integrates pyropheophorbide α as a photosensitizer and a NIR fuorophore for tumor imaging. The two functionalities are linked with a hypoxic‑sensitive azo group. Under normal conditions, both the phototoxicity of the photosensitizer and the fuorescence of the fuorophore are inhibited. While under hypoxic condition, the reductive cleavage of the azo group will restore both functions, leading to tumor specifc fuorescence imaging and phototoxicity. The results showed that azo‑PDT selectively images BEL‑7402 cells under hypoxia, and simultaneously inhibits BEL‑7402 cell proliferation after near‑infrared irradiation under hypoxia, while little efect on BEL‑7402 cell viability was observed under normoxia. These results confrm the feasibility of our design strategy to improve the tumor‑ targeting ability of photodynamic therapy, and presents azo‑pDT probe as a promising dual functional agent. Cancer is one of the most common causes of death, and more and more therapeutic strategies against this fatal disease have emerged in the past few decades. Among these strategies, photodynamic therapy has attracted much attention1. Tis therapy is based on singlet oxygen produced by photosensitizers under the irradiation with light of a specifc wavelength to damage tumor tissues (Fig. 1a). Since the photo-damaging efect is induced by the interaction between a photosensitizer and light, tumor-specifc therapy may be realized by focusing the light to the tumor site.
    [Show full text]
  • Fluorescent Protein-Based Tools for Neuroscience
    !1 !2 Fluorescent protein-based tools Outline for neuroscience An animatd primer on biosensor development Fluorescent proteins (FPs) Robert E. Campbell Department of Chemistry Other fluorophore technologies Single FP-based biosensors Imaging Structure & Function in the Nervous System Cold Spring Harbor, July 31, 2019. Lots of structural Lots of structural information information & Transmitted light Fluorescence microscopy of fluorescent color microscopy of live cells live cells No molecular provides molecular information information (more colors = more information) !5 !6 Fluorescence microscopy requires fluorophores Non-natural fluorophores for protein labelling Trends Bioch. Sci., 1984, 9, 88-91. O O O N O N 495 nm 519 nm 557 nm 576 nm - - CO2 CO2 S O O O N O N C N N C S ϕ = quantum yield - - ε = extinction coefficient CO2 CO2 ϕ Brightness ~ * ε S C i.e., for fluorescein N Proteins of interest ϕ = 0.92 N Fluorescein Tetramethylrhodamine ε = 73,000 M-1cm-1 C S (FITC) (TRITC) A non-natural fluorophore must be chemically linked to Non-natural fluorophores made by chemical synthesis a protein of interest… !7 !8 Getting non-natural fluorophores into a cell Some sea creatures make natural fluorophores Trends Bioch. Sci., 1984, 9, 88-91. O O O N O N Bioluminescent - Fluorescent CO2 CO -- S 2 S C N NHN C H S S Chemically labeled proteins of interest Microinjection with micropipet O O O N O N Fluorescent - CO2 CO - S 2 N NH H S …and then manually injected into a cell Some natural fluorophores are genetically encoded proteins http://www.luminescentlabs.org/and can be transplanted into cells as DNA! 228 OSAMU SHIMOMURA, FRANK H.
    [Show full text]
  • Fluorophore Referenceguide
    Fluorophore Reference Guide Fluorophore Excitation and Emission Data Laser Lines Broad UV Excitation Excitation Maxima Emission Maxima Emission Filters 290-365 nm LP = Long pass filter DF = Band pass filter Excel. ___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ DAPI: 359 nm ____ SP = Short pass filter Good ___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ GFP (Green Fluorescent Protein): 395 nm ____ 400 nm Good ___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Coumarin: 402 nm ____ 425 nm Good ___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ AttoPhos: 440 nm ____ ____ 443 nm: Coumarin 450 nm Good ___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Acridine Orange: 460/500 nm ____ ____ 461 nm: DAPI Good __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ R-phycoerythrin: 480/565 nm ____ Excel.
    [Show full text]
  • Water-Soluble Pyrrolopyrrole Cyanine (Ppcy) NIR Fluorophores† Cite This: Chem
    Erschienen in: Chemical Communications ; 2014, 50. - S. 4755-4758 ChemComm View Article Online COMMUNICATION View Journal | View Issue Water-soluble pyrrolopyrrole cyanine (PPCy) NIR fluorophores† Cite this: Chem. Commun., 2014, 50, 4755 Simon Wiktorowski, Christelle Rosazza, Martin J. Winterhalder, Ewald Daltrozzo Received 7th February 2014, and Andreas Zumbusch* Accepted 21st March 2014 DOI: 10.1039/c4cc01014k www.rsc.org/chemcomm Water-soluble derivatives of pyrrolopyrrole cyanines (PPCys) have been dyes, BODIPYs or others.7 Notable are also advances in other fields, synthesized by a post-synthetic modification route. In highly polar like the engineering of GFP-related fluorescing proteins or quantum media, these dyes are excellent NIR fluorophores. Labeling experiments dots, which have resulted in the synthesis of novel systems with NIR show how these novel dyes are internalized into mammalian cells. emission.8 To date, however, only a few water-soluble dyes with strong NIR absorptions and emissions have been known. Apart from the Near-infrared (NIR) light absorbing and emitting compounds have general scarcity of NIR absorbing molecules, the main reason for this attracted a lot of interest since the 1990’s.1 Initially, this was motivated is that NIR absorption is commonly observed in extended p-systems by their use in optical data storage or as laser dyes. Recently, however, which most often are hydrophobic. The incorporation of hydrophilic new applications of NIR dyes have emerged, which has led to a surge of functionalities into
    [Show full text]
  • Chemical Probes to Visualize Bacterial Cell Structure and Physiology
    molecules Review From Differential Stains to Next Generation Physiology: Chemical Probes to Visualize Bacterial Cell Structure and Physiology Jonathan Hira 1, Md. Jalal Uddin 1 , Marius M. Haugland 2 and Christian S. Lentz 1,* 1 Research Group for Host-Microbe Interactions, Department of Medical Biology and Centre for New Antibacterial Strategies (CANS), UiT—The Arctic University of Norway, 9019 Tromsø, Norway; [email protected] (J.H.); [email protected] (M.J.U.) 2 Department of Chemistry and Centre for New Antibacterial Strategies (CANS), UiT—The Arctic University of Norway, 9019 Tromsø, Norway; [email protected] * Correspondence: [email protected] Academic Editor: Steven Verhelst Received: 30 September 2020; Accepted: 23 October 2020; Published: 26 October 2020 Abstract: Chemical probes have been instrumental in microbiology since its birth as a discipline in the 19th century when chemical dyes were used to visualize structural features of bacterial cells for the first time. In this review article we will illustrate the evolving design of chemical probes in modern chemical biology and their diverse applications in bacterial imaging and phenotypic analysis. We will introduce and discuss a variety of different probe types including fluorogenic substrates and activity-based probes that visualize metabolic and specific enzyme activities, metabolic labeling strategies to visualize structural features of bacterial cells, antibiotic-based probes as well as fluorescent conjugates to probe biomolecular uptake pathways. Keywords: activity-based probe; antibiotic conjugate; bacterial imaging; bacterial uptake; fluorogenic substrate; metabolic labeling; phenotypic heterogeneity 1. Introduction—From 19th Century Microbiology to Modern Day Chemical Biology If chemical biology can be defined as the ‘interrogation of biological systems with chemical approaches’ [1], we must acknowledge some of the first microbiologists as chemical biologists.
    [Show full text]
  • Near-Infrared Genetically Encoded Positive Calcium Indicator Based on GAF-FP Bacterial Phytochrome
    Near-infrared genetically encoded positive calcium indicator based on GAF-FP bacterial phytochrome The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Subach,Oksana M., Natalia V. Barykina, Konstantin V. Anokhin, Kiryl D. Piatkevich, and Fedor V. Subach, "Near-infrared genetically encoded positive calcium indicator based on GAF-FP bacterial phytochrome." International Journal of Molecular Sciences 20, 14 (July 2019): no. 3488 doi 10.3390/ijms20143488 ©2019 Author(s) As Published 10.3390/ijms20143488 Publisher Multidisciplinary Digital Publishing Institute Version Final published version Citable link https://hdl.handle.net/1721.1/125333 Terms of Use Creative Commons Attribution Detailed Terms https://creativecommons.org/licenses/by/4.0/ International Journal of Molecular Sciences Article Near-Infrared Genetically Encoded Positive Calcium Indicator Based on GAF-FP Bacterial Phytochrome 1, 2, 2,3 Oksana M. Subach y , Natalia V. Barykina y , Konstantin V. Anokhin , Kiryl D. Piatkevich 4 and Fedor V. Subach 1,* 1 National Research Center “Kurchatov Institute”, Moscow 123182, Russia 2 P.K. Anokhin Institute of Normal Physiology, Moscow 125315, Russia 3 Lomonosov Moscow State University, Moscow 119991, Russia 4 MIT Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA * Correspondence: [email protected]; Tel.: +07-968-962-7083 These authors contributed equally to this work. y Received: 31 May 2019; Accepted: 15 July 2019; Published: 16 July 2019 Abstract: A variety of genetically encoded calcium indicators are currently available for visualization of calcium dynamics in cultured cells and in vivo. Only one of them, called NIR-GECO1, exhibits fluorescence in the near-infrared region of the spectrum.
    [Show full text]
  • Orientation of Cyanine Fluorophores Terminally Attached to DNA Via Long, Flexible Tethers
    1148 Biophysical Journal Volume 101 September 2011 1148–1154 Orientation of Cyanine Fluorophores Terminally Attached to DNA via Long, Flexible Tethers Jonathan Ouellet, Stephanie Schorr, Asif Iqbal, Timothy J. Wilson, and David M. J. Lilley* Cancer Research UK Nucleic Acid Structure Research Group, The University of Dundee, Dundee, United Kingdom ABSTRACT Cyanine fluorophores are commonly used in single-molecule FRET experiments with nucleic acids. We have previously shown that indocarbocyanine fluorophores attached to the 50-termini of DNA and RNA via three-carbon atom linkers stack on the ends of the helix, orienting their transition moments. We now investigate the orientation of sulfoindocarbocyanine fluorophores tethered to the 50-termini of DNA via 13-atom linkers. Fluorescence lifetime measurements of sulfoindocarbocya- nine 3 attached to double-stranded DNA indicate that the fluorophore is extensively stacked onto the terminal basepair at 15C, with properties that depend on the terminal sequence. In single molecules of duplex DNA, FRET efficiency between sulfoindo- carbocyanine 3 and 5 attached in this manner is modulated with helix length, indicative of fluorophore orientation and consistent with stacked fluorophores that can undergo lateral motion. We conclude that terminal stacking is an intrinsic property of the cyanine fluorophores irrespective of the length of the tether and the presence or absence of sulfonyl groups. However, compared to short-tether indocarbocyanine, the mean rotational relationship between the two fluorophores is changed by ~60 for the long- tether sulfoindocarbocyanine fluorophores. This is consistent with the transition moments becoming approximately aligned with the long axis of the terminal basepair for the long-linker species.
    [Show full text]
  • Molecular and Spectroscopic Characterization of Green and Red Cyanine Fluorophores from the Alexa Fluor and AF Series
    bioRxiv preprint doi: https://doi.org/10.1101/2020.11.13.381152; this version posted November 15, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Gebhardt et al., Molecular and spectroscopic characterization of green and red cyanine fluorophores from the Alexa Fluor and AF series Molecular and spectroscopic characterization of green and red cyanine fluorophores from the Alexa Fluor and AF series Christian Gebhardt1, Martin Lehmann2, Maria M. Reif3, Martin Zacharias3 & Thorben Cordes1,* 1 Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany 2 Plant Molecular Biology and Plant Metabolism, Faculty of Biology, Ludwig-Maximilians- Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany 3 Theoretical Biophysics (T38), Physics Department, Technical University of Munich, München, Germany corresponding author email: [email protected] Abstract The use of fluorescence techniques has had an enormous impact on various research fields including imaging, biochemical assays, DNA-sequencing and medical technologies. This has been facilitated by the availability of numerous commercial dyes, but often information about the chemical structures of dyes (and their linkers) are a well-kept secret. This can lead to problems for applications where a knowledge of the dye structure is necessary to predict (unwanted) dye-target interactions, or to establish structural models of the dye-target complex. Using a combination of spectroscopy, mass spectrometry and molecular dynamics simulations, we here investigate the molecular structures and spectroscopic properties of dyes from the Alexa Fluor (Alexa Fluor 555 and 647) and AF series (AF555, AF647, AFD647).
    [Show full text]
  • Fluorescence Spectroscopy of Exogenous, Exogenously-Induced and Endogenous Fluorophores for the Photodetection and Photodynamic Therapy of Cancer
    FLUORESCENCE SPECTROSCOPY OF EXOGENOUS, EXOGENOUSLY-INDUCED AND ENDOGENOUS FLUOROPHORES FOR THE PHOTODETECTION AND PHOTODYNAMIC THERAPY OF CANCER. Thèse présentée au Département de Génie Rural Ecole Polytechnique Fédérale de Lausanne par Matthieu Zellweger Jury: Dr Georges Wagnières, rapporteur Prof. Hubert van den Bergh, corapporteur Dr Christian Depeursinge, corapporteur Prof. René Salathé, corapporteur Prof. Philippe Monnier, corapporteur Prof. Stanley Brown, corapporteur Lausanne, Février 2000 2 Foreword This work is the final report about my research activity as a Ph.D. student in the LPAS laboratory of Prof. Hubert van den Bergh, at the Swiss Federal Institute of Technology - Lausanne (EPFL). Some parts of this report have been published or submitted during the course of my Ph.D. thesis. I therefore included the text of the publications instead of an original chapter whenever relevant. In such a case, the reference is clearly stated. A brief introduction always precedes the resulting 'chapters'. Due to this inclusion, the reader might find some redundant information within this report. On the other hand, it should be emphasized that each chapter can be read as a stand-alone text and need not be linked to any other part of the whole work. However, I tried to avoid the unnecessary repetition of information and this is especially true for the references. Whenever the reader feels that a reference should have been included to support an information in the introduction, they should check the introduction of the following published chapter for a more detailed reference list. The same criticism applies to the introduction and, again, the reader should check the published section of a chapter if they feel that it lacks some information.
    [Show full text]
  • The Structure of the Chromophore Within Dsred, a Red Fluorescent Protein from Coral
    The structure of the chromophore within DsRed, a red fluorescent protein from coral Larry A. Gross*†, Geoffrey S. Baird‡, Ross C. Hoffman†§, Kim K. Baldridge§¶, and Roger Y. Tsien*†§ʈ *Department of Pharmacology, ‡Medical Scientist Training Program and Biomedical Sciences Program, †Howard Hughes Medical Institute, §Department of Chemistry and Biochemistry, and ¶San Diego Supercomputer Center, University of California, San Diego, La Jolla, CA 92093 Contributed by Roger Y. Tsien, August 16, 2000 DsRed, a brilliantly red fluorescent protein, was recently cloned bonds. The resulting acylimine substituent quantitatively ac- from Discosoma coral by homology to the green fluorescent counts for the red shift by detailed quantum chemical calcula- protein (GFP) from the jellyfish Aequorea. A core question in the tions. It also explains why the DsRed chromophore shifts back biochemistry of DsRed is the mechanism by which the GFP-like to a GFP-like absorbance spectrum upon protein denaturation 475-nm excitation and 500-nm emission maxima of immature and why harsher treatments cleave DsRed into two fragments. DsRed are red-shifted to the 558-nm excitation and 583-nm emis- sion maxima of mature DsRed. After digestion of mature DsRed Materials and Methods with lysyl endopeptidase, high-resolution mass spectra of the Mass Spectral Analysis of LysC Digests. Approximately 2 nmol of purified chromophore-bearing peptide reveal that some of the His-tagged DsRed protein or its K83R mutant (1) was evaporated molecules have lost 2 Da relative to the peptide analogously to near dryness in vacuo then resuspended in 3 ␮lof6M prepared from a mutant, K83R, that stays green.
    [Show full text]
  • Tuning the Baird Aromatic Triplet-State Energy of Cyclooctatetraene to Maximize the Self-Healing Mechanism in Organic Fluorophores
    Tuning the Baird aromatic triplet-state energy of cyclooctatetraene to maximize the self-healing mechanism in organic fluorophores Avik K. Patia,b, Ouissam El Bakouric,1, Steffen Jockuschd,1, Zhou Zhoua,1, Roger B. Altmana,b, Gabriel A. Fitzgeralda, Wesley B. Ashere,f,g, Daniel S. Terrya,b, Alessandro Borgiab, Michael D. Holseye,f, Jake E. Batcheldera,b, Chathura Abeywickramab, Brandt Huddlea, Dominic Rufaa, Jonathan A. Javitche,f,g, Henrik Ottossonc, and Scott C. Blancharda,b,2 aDepartment of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065; bDepartment of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105; cÅngström Laboratory, Department of Chemistry, Uppsala University, Uppsala, 751 20 Sweden; dDepartment of Chemistry, Columbia University, New York, NY 10027; eDepartment of Psychiatry, Columbia University, New York, NY 10032; fDepartment of Pharmacology, Columbia University, New York, NY 10032; and gDivision of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032 Edited by Taekjip Ha, Johns Hopkins University, Baltimore, MD, and approved August 17, 2020 (received for review April 7, 2020) Bright, photostable, and nontoxic fluorescent contrast agents are which can generate toxic reactive oxygen species (ROS). ROS include critical for biological imaging. “Self-healing” dyes, in which triplet singlet oxygen, peroxide, and superoxide radicals that lead to chem- states are intramolecularly quenched, enable fluorescence imaging ical destruction of the fluorophore (photobleaching), photocross- by increasing fluorophore brightness and longevity, while simul- linking to elements in the surrounding environment, and other po- taneously reducing the generation of reactive oxygen species that tentially toxic side effects (7–11). promote phototoxicity.
    [Show full text]