Download or read book Applications of Tryptophan Triplet State Spectroscopy to Studies of Protein Dynamics written by Christopher James Fischer and published by . This book was released on 2000 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopy of Tryptophan in Electron Transfer and Membrane Protein Folding written by Ignacio Lopez Pena and published by . This book was released on 2017 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The tryptophan fluorescence of proteins has been widely used to examine protein structure, ligand binding, and conformational changes. The triplet state is also well suited for examining protein structure and dynamics because of its long lifetime in some proteins, up to seconds. This dissertation focuses on several aspects of the tryptophan triplet, especially the photochemistry and photophysics of this chromophore in electron transfer and membrane protein folding. Chapter 3 describes the role of the tryptophan triplet state in mediating intermolecular electron transfer (ET). The ET rate across large distances is slow relative to a typical fluorescence lifetime. The photooxidation reaction of tryptophan in mutants of apo- and Zn(II)azurin is shown to involve the triplet state via measurements of triplet absorption and phosphorescence in the presence of an external electron acceptor. The formation of neutral radical is demonstrated to coincide with quenched phosphorescence. The formation kinetics of the triplet state and neutral radical were modeled, and the results of 1×10^7 and 8×10^5 sec-1, respectively, agree with a proposed intermolecular ET pathway (~18 Å) along 10 covalent bonds and two through-space steps. The tryptophan triplet decay kinetics are known to be different in D2O compared to H2O. This isotope effect is correlated with local solvent accessibility, and can be used to examine changes in hydration during membrane protein folding. Chapter 4 describes experiments on a model tryptophan compound, a membrane-associated peptide (melittin), and a transmembrane protein (OmpA). An isotope effect was present when tryptophan was exposed to bulk solvent, such as in unfolded melittin kH2O/kD2O=0.71, but disappeared when buried in a bilayer, such as in folded melittin kH2O/kD2O=1.07. Additionally, when OmpA was bound to the native molecular chaperone Skp, an isotope effect was absent kH2O/kD2O=1.0 . These results suggest Skp plays a role in desolvating OmpA, allowing OmpA to fold into the bilayer more easily. These data indicate that triplet photophysics may be a general tool to determine changes in hydration for proteins. Finally, spectroscopy of protein chromophores, including tryptophan, and prosthetic groups reveals local structure and dynamics. Chapter 5 discusses applications of UV and visible resonance Raman spectroscopy to proteins.
Download or read book Application of Time resolved Tryptophan Phosphoresence Spectroscopy to Protein Folding Studies written by Vinod Subramaniam and published by . This book was released on 1996 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biochemical Applications written by Joseph R. Lakowicz and published by Springer Science & Business Media. This book was released on 1992-02-29 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluorescence spectroscopy and its applications to the physical and life sciences have evolved rapidly during the past decade. The increased interest in fluorescence appears to be due to advances in time resolution, methods of data analysis and improved instrumentation. With these advances, it is now practical to perform time-resolved measurements with enough resolution to compare the results with the structural and dynamic features of mac- molecules, to probe the structures of proteins, membranes, and nucleic acids, and to acquire two-dimensional microscopic images of chemical or protein distributions in cell cultures. Advances in laser and detector technology have also resulted in renewed interest in fluorescence for clinical and analytical chemistry. Because of these numerous developments and the rapid appearance of new methods, it has become difficult to remain current on the science of fluorescence and its many applications. Consequently, I have asked the experts in particular areas of fluorescence to summarize their knowledge and the current state of the art. This has resulted in the initial three volumes of Topics in Fluorescence Spectroscopy, which is intended to be an ongoing series which summarizes, in one location, the vast literature on fluorescence spectroscopy. These first three volumes are designed to serve as an advanced text. These volumes describe the more recent techniques and technologies (Volume 1), the principles governing fluorescence and the experimental observables (Volume 2), and applications in biochemistry and biophysics (Volume 3).
Download or read book Ultraviolet Spectroscopy of Proteins written by Alexander P. Demchenko and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to give a comprehensive description of the basic methods used in the ultraviolet spectroscopy of proteins, to discuss new trends and development of these methods, and to analyze their different applications in the study of various aspects of protein structure and dynamics. Ultraviolet spectroscopy is one of the oldest and most popular methods in the field of biochemistry and molecular biophysics. At present, it is difficult to imagine the biochemical laboratory without a recording spectrophotometer or spectrofluorimeter. There are several hundreds of publications directly devoted to protein ultraviolet spectroscopy and in a great number of studies UV spectroscopic methods are used for the structural analysis of different proteins. Meanwhile a unified description of the theoretical basis of the methods, experimental techniques, data analysis, and generalization of results obtained in solving the specific problems of protein structure are lacking. There are three reasons for which a monograph on ultraviolet spectroscopy is needed today. Firstly, there has been significant growth in facilities of experimental technique, its precision, and versatility associated with computer data analysts. This new technique is available to a wide circle of scientists engaged in the field of protein research. Most of them are not spectroscopists and, thus, there is a need for a conceivable and precise source of information on how to use this method and what kind of data it should provide.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2004 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Approaches to the Conformational Analysis of Biopharmaceuticals written by Roger L. Lundblad and published by CRC Press. This book was released on 2009-12-15 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The activity of many biopharmaceutical polymers is dependent on conformation, and the next several years will see increased interest in the conformational analysis of these polymers resulting from the development of biosimilar or "follow-on" biological products. While a wide variety of approaches to analysis exists, finding the most viable ones wou
Download or read book Vibrational and Quantum Yield Studies of Deuterated Tryptophan Radical in Azurin written by Justine Hwai-Han Liang and published by . This book was released on 2017 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Long-range electron transfer has been observed in several complex biological systems, including photosynthetic complexes to redox enzymes in DNA repair pathways. The efficiency of electron tunneling and hopping through amino acid mediators, including tyrosine and tryptophan, has been reported in the past. In particular, tryptophan residues are redox active and can function as electron transfer (ET) intermediates through progressive conversion to cation and neutral radical. The current work extends upon the published studies of the tryptophan radical at position 48 of the zinc-substituted protein, azurin (denoted ZnIIAz48W) by focusing on the effect of isotopic substitution on electron and protein transfer steps. Two ZnIIAz48W isotopologues of trp-48 are studied here: perdeuterated D5- ZnIIAz48W and singly- deuterated ND- ZnIIAz48W. These isotopologues were characterized by UV- and visible-resonance Raman spectroscopy for both the closed shell and neutral radical forms, respectively. Isotope effects were also observed in the fluorescence and radical quantum yields. The fluorescence and phosphorescence intensities, in the presence and absence of an external electron acceptor, indicate that the triplet state may be involved in the ET and cation radical formation pathways. The quantum yield for formation of D5- ZnIIAz48W is consistent with ET from the triplet state. In the case of ND- ZnIIAz48W, ET also likely occurs from the triplet state, but there is an additional effect because deprotonation of the heavy deuteron reduces the quantum yield for radical formation by a factor of 0.67 relative to NH- ZnIIAz48W. These isotope studies of Trp-48 in azurin help clarify the sequential ET/PT steps for trp-48 in azurin, and provide general insights into this complex biological process.
Download or read book Protein Fluorescence written by Joseph R. Lacowicz and published by Springer Science & Business Media. This book was released on 2006-04-18 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: The intrinsic or natural fluorescence of proteins is perhaps the most complex area of biochemical fluorescence. Fortunately the fluorescent amino acids, phenylalanine, tyrosine and tryptophan are relatively rare in proteins. Tr- tophan is the dominant intrinsic fluorophore and is present at about one mole % in protein. As a result most proteins contain several tryptophan residues and even more tyrosine residues. The emission of each residue is affected by several excited state processes including spectral relaxation, proton loss for tyrosine, rotational motions and the presence of nearby quenching groups on the protein. Additionally, the tyrosine and tryptophan residues can interact with each other by resonance energy transfer (RET) decreasing the tyrosine emission. In this sense a protein is similar to a three-particle or mul- particle problem in quantum mechanics where the interaction between particles precludes an exact description of the system. In comparison, it has been easier to interpret the fluorescence data from labeled proteins because the fluorophore density and locations could be controlled so the probes did not interact with each other. From the origins of biochemical fluorescence in the 1950s with Prof- sor G. Weber until the mid-1980s, intrinsic protein fluorescence was more qualitative than quantitative. An early report in 1976 by A. Grindvald and I. Z. Steinberg described protein intensity decays to be multi-exponential. Attempts to resolve these decays into the contributions of individual tryp- phan residues were mostly unsuccessful due to the difficulties in resolving closely spaced lifetimes.
Download or read book Cumulated Index Medicus written by and published by . This book was released on 1999 with total page 1846 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time resolved Laser Spectroscopy in Biochemistry III written by Joseph R. Lakowicz and published by . This book was released on 1992 with total page 834 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Cereals and Flours written by Gonul Kaletunc and published by CRC Press. This book was released on 2019-07-17 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: Characterization of Cereals and Flours is a state-of-the-art reference that details the latest advances to characterize the effects of manufacturing processes and storage conditions on the thermal, mechanical, and structural properties of cereal flours and their products - examining the influence of moisture absorption, storage temperature, baking, and extrusion processing on flour and cereal product texture, shelf-life, and quality. The book discusses the influence of additives on pre- and postprocessed food biopolymers; the development of databases and construction of state diagrams to illustrate the state and function of cereal flours before, during, and after production; and the current techniques in image analysis, light and electron microscopy, and NMR spectroscopy used to analyze the microstructure of cereal products. It also discusses the methods used to optimize processing parameters and formulations to produce end-products with desirable sensory and textural properties; the shelf life of cereal products; and the relationships between the sensory and physical characteristics of cereal foods.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lasers in Polymer Science and Technolgy written by Jan F. Rabek and published by CRC Press. This book was released on 1989-11-30 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this 4-volume set is to examine some of the applications of lasers in polymer science and technology. Now available for the first time, up-to-date information on this fascinating subject is compiled and presented in compact form. This set focuses on current research and developments in the application of lasers in polymer and biopolymer chemistry. It includes experimental and theoretical details, apparatus, techniques, and applications. This set is a useful source for researchers, students, polymer chemists, and physicists involved in this astonishing field of high technology.
Download or read book Photoacoustic and Photothermal Spectroscopy written by Surya N. Thakur and published by Elsevier. This book was released on 2022-12-07 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photoacoustic and Photothermal Spectroscopy: Principles and Applications introduces the basic principles, instrumentation and major developments in the many applications of Photoacoustic and Photothermal Spectroscopy over the last three decades. The book explains the processes of sound generation by periodic optical excitation and ultrasonic generation by pulsed laser excitation and describes the workings of photoacoustic cells equipped with microphones and piezoelectric transducers. Photoacoustic imaging (PAI) is one of the fastest-growing imaging modalities of recent times. It combines the advantages of ultrasound and optical imaging techniques. These non-invasive and non-destructive techniques offer many benefits to users by enabling spectroscopy of opaque and inhomogeneous materials, (solid, liquid, powder, gel, gases) without any sample preparation, and more. Written in a non-mathematical, simple-to-read manner Presents recent developments in the field, along with the scope of future progress, including up-to-date references Includes detailed illustrations, such as equipment layout, spectra, experimental setups, tables, photographs, and more
Download or read book Essential Amino Acids Advances in Research and Application 2012 Edition written by and published by ScholarlyEditions. This book was released on 2012-12-26 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Essential Amino Acids—Advances in Research and Application: 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Essential Amino Acids. The editors have built Essential Amino Acids—Advances in Research and Application: 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Essential Amino Acids in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Essential Amino Acids—Advances in Research and Application: 2012 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book Research Awards Index written by and published by . This book was released on 1978 with total page 1380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
