Download or read book Solid state Deuterium and REDOR NMR Structural Studies of Spider Dragline Silk and a New Experiment for Measuring Multiple Heteronuclear Dipolar Couplings in Solids written by Carl August Michal and published by . This book was released on 1997 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1998 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solid state NMR Techniques for Dipolar Coupling Measurements in Locally ordered Biological Solids written by Rebecca Ann Shapiro and published by . This book was released on 2011 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the low-viscosity samples used in solution-state nuclear magnetic resonance (NMR) spectroscopy, molecular tumbling occurs on a much faster timescale than a single NMR experiment. As a result, anisotropic interactions between the nuclei average to zero and sharp, narrow, isotropic lineshapes are easily obtained. However, in systems with local order, rotational and translation mobility of molecules is signifcantly reduced. In this solid-state regime, anisotropic interactions are no longer motionally averaged, and three additional effects are observed to severely complicate NMR spectra: heteronuclear and homonuclear dipolar couplings, and chemical shift anisotropy (CSA). Magic-angle spinning (MAS) is a solid-state NMR (ssNMR) technique that makes it possible to mechanically average these anisotropic effects to zero and acquire sharp, isotropic peaks analogous to those found in solution. However, the presence of dipolar couplings and CSA allows additional structural information about biomolecules to be extracted; so there is demand for ssNMR techniques that take advantage of anisotropic interactions. Switched angle spinning (SAS) is one such method that can be used for structural studies of oriented biological samples. SAS combines the advantage of the magic angle spinning with the structural information provided by heteronuclear and homonuclear dipolar couplings and CSA by correlating isotropic chemical shifts in one dimension with anisotropic information in a second dimension. Presented herein is current work on two related research efforts: the development and characterization of a new biologically-relevant alignment medium with increased thermal stability ideal for recovery of additional structural constraints from dipolar couplings and CSA in membrane proteins and peptides, and simulation work laying the foundation for new SAS experiments optimized for structural studies of membrane proteins, peptides, and other biomolecules with local order induced by bicelles or other liquid-crystalline alignment media.
Download or read book Determination of Structure in Heterogeneous Solids Using Heteronuclear Dipolar Coupling Solid state NMR written by Erin Elizabeth Wilson and published by . This book was released on 2005 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Indirectly Detected Chemical Shift Correlation NMR Spectroscopy in Solids Under Fast Magic Angle Spinning written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of fast magic angle spinning (MAS) opened up an opportunity for the indirect detection of insensitive low-[gamma] nuclei (e.g., 13C and 15N) via the sensitive high-[gamma] nuclei (e.g., 1H and 19F) in solid-state NMR, with advanced sensitivity and resolution. In this thesis, new methodology utilizing fast MAS is presented, including through-bond indirectly detected heteronuclear correlation (HETCOR) spectroscopy, which is assisted by multiple RF pulse sequences for 1H-1H homonuclear decoupling. Also presented is a simple new strategy for optimization of 1H-1H homonuclear decoupling. As applications, various classes of materials, such as catalytic nanoscale materials, biomolecules, and organic complexes, are studied by combining indirect detection and other one-dimensional (1D) and two-dimensional (2D) NMR techniques. Indirectly detected through-bond HETCOR spectroscopy utilizing refocused INEPT (INEPTR) mixing was developed under fast MAS (Chapter 2). The time performance of this approach in 1H detected 2D 1H[13C] spectra was significantly improved, by a factor of almost 10, compared to the traditional 13C detected experiments, as demonstrated by measuring naturally abundant organic-inorganic mesoporous hybrid materials. The through-bond scheme was demonstrated as a new analytical tool, which provides complementary structural information in solid-state systems in addition to through-space correlation. To further benefit the sensitivity of the INEPT transfer in rigid solids, the combined rotation and multiple-pulse spectroscopy (CRAMPS) was implemented for homonuclear 1H decoupling under fast MAS (Chapter 3). Several decoupling schemes (PMLG5{sub m}{sup {bar x}}, PMLG5{sub mm}{sup {bar x}x} and SAM3) were analyzed to maximize the performance of through-bond transfer based on decoupling efficiency as well as scaling factors. Indirect detection with assistance of PMLG{sub m}{sup {bar x}} during INEPTR transfer proved to offer the highest sensitivity gains of 3-10. In addition, the CRAMPS sequence was applied under fast MAS to increase the 1H resolution during t1 evolution in the traditional, 13C detected HETCOR scheme. Two naturally abundant solids, tripeptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (f-MLF-OH) and brown coal, with well ordered and highly disordered structures, respectively, are studied to confirm the capabilities of these techniques. Concomitantly, a simple optimization of 1H homonuclear dipolar decoupling at MAS rates exceeding 10 kHz was developed (Chapter 4). The fine-tuned decoupling efficiency can be obtained by minimizing the signal loss due to transverse relaxation in a simple spin-echo experiment, using directly the sample of interest. The excellent agreement between observed decoupling pattern and earlier theoretical predictions confirmed the utility of this strategy. The properties of naturally abundant surface-bound fluorocarbon groups in mesoporous silica nanoparticles (MSNs) were investigated by the above-mentioned multidimensional solid-state NMR experiments and theoretical modeling (Chapter 5). Two conformations of (pentafluorophenyl)propyl groups (abbreviated as PFP) were determined as PFP-prone and PFP-upright, whose aromatic rings are located above the siloxane bridges and in roughly upright position, respectively. Several 1D and 2D NMR techniques were implemented in the characterizations, including indirectly detected 1H[13C] and 19F[13C] 2D HETCOR, Carr-Purcell-Meiboom-Gill (CPMG) assisted 29Si direct polarization and 29Si19F 2D experiments, 2D double-quantum (DQ) 19F MAS NMR spectra and spin-echo measurements. Furthermore, conformational details of two types of PFP were confirmed by theoretical calculation, operated by Dr. Takeshi Kobayashi. Finally, the arrangement of two surfactants, cetyltrimetylammoium bromide (CTAB) and cetylpyridinium bromide (CPB), mixed inside the MSN pores, was studied by solid-state NMR (Chapter 6). By analyzing the 1H-1H DQMAS and NOESY correlation spectra, the CTAB and CPB molecules were shown to co-exist inside the pores without forming significant monocomponent domains. A 'folded-over' conformation of CPB headgroups was proposed according to the results from 1H-29Si 2D HETCOR.
Download or read book Solid state NMR Elucidation of Molecular Structure in Spider Dragline Silk Proteins written by Janelle Estelle Jenkins and published by . This book was released on 2010 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Peptides written by Bernd Gutte and published by Elsevier. This book was released on 1995-10-24 with total page 527 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, research has shown the importance of peptides in neuroscience, immunology, and cell biology. Active research programs worldwide are now engaged in developing peptide-based drugs and vaccines using modification of natural peptides and proteins, design of artificial peptides and peptide mimetics, and screening of peptide and phage libraries. In this comprehensive book, the authors discuss peptide synthesis and application within the context of their increasing importance to the pharmaceutical industry. Peptides: Synthesis, Structures, and Applications explores the broad growth of information in modern peptide synthetic methods and the structure-activity relationships of synthetic polypeptides. - The history of peptide chemistry - Amide formation, deprotection, and disulfide formation in peptide synthesis - Solid-phase peptide synthesis - a-helix formation by peptides in water - Stability and dynamics of peptide conformation - An overview of structure-function studies of peptide hormones - Neuropeptides:peptide and nonpeptide analogs - Reversible inhibitors of serine proteinases - Design of polypeptides - Current capabilities and future possibilities of soluble chemical combinatorial libraries - Epitope mapping with peptides - Synthesis and applications of branched peptides in immunological methods and vaccines
Download or read book Biotechnology of Silk written by Tetsuo Asakura and published by Springer Science & Business Media. This book was released on 2013-10-21 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a snapshot of the current state of the art of research and development on the properties and characteristics of silk and their use in medicine and industry. The field encompasses backyard silk production from ancient time to industrial methods in the modern era and includes an example of efforts to maintain silk production on Madagascar. Once revered as worth its weight in gold, silk has captured the imagination from its mythical origins onwards. The latest methods in molecular biology have opened new descriptions of the underlying properties of silk. Advances in technological innovation have created silk production by microbes as the latest breakthrough in the saga of silk research and development. The application of silk to biomaterials is now very active on the basis of excellent properties of silks including recombinant silks for biomaterials and the accumulated structural information.
Download or read book Solid State NMR of Polymers written by T. Asakura and published by Elsevier. This book was released on 1998-08-03 with total page 1017 pages. Available in PDF, EPUB and Kindle. Book excerpt: In polymer science and technology, the advanced development of various new polymer materials with excellent properties and functions is desirable. For this purpose it is necesary to determine the exact relationship between physical properties and molecular structure-dynamics with powerful techniques. One such technique is solid state NMR. Recently, high resolution NMR studies of solids have been realized by using advanced pulse and mechanical techniques, which has resulted in a variety of structural and dynamical information on polymer systems. Solid state NMR has provided characteristic information which cannot be obtained by other spectroscopic methods.This book is divided into two parts. The first part covers the principles of NMR, important NMR parameters such as chemical shifts, relaxation times, dipolar interactions, quadrupolar interactions, pulse techniques and new NMR methods. In the second part, applications of NMR to a variety of polymer systems in the solid state are described.Features of this book:• Contains an up-to-date and comprehensive account of solid state NMR of polymers by leading researchers in the field• Provides a compilation of solid state NMR of polymers, which makes it an ideal reference book for both NMR researchers and general polymer scientists.This book will be of interest to the NMR community, and will be invaluable for both the beginner and the expert.
Download or read book Alphaherpesviruses written by Sandra Knowles Weller and published by Caister Academic Press Limited. This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alphaherpesviruses are a fascinating group of DNA viruses that includes important human pathogens such as herpes simplex virus type 1 (HSV-1), HSV-2, and varicella-zoster virus (VZV): the causative agents of cold sores, genital ulcerous disease, and chickenpox/shingles, respectively. A key attribute of these viruses is their ability to establish lifelong latent infection in the peripheral nervous system of the host. Such persistence requires subversion of the host's immune system and intrinsic antiviral defense mechanisms. Understanding the mechanisms of the immune evasion and what triggers viral reactivation is a major challenge for today's researchers. This has prompted enormous research efforts into understanding the molecular and cellular biology of these viruses. This up-to-date and comprehensive volume aims to distill the most important research in this area providing a timely overview of the field. Topics covered include: transcriptional regulation, DNA replication, translational control, virus entry and capsid assembly, the role of microRNAs in infection and oncolytic vectors for cancer therapy. In addition there is coverage of virus-host interactions, including apoptosis, subversion of host protein quality control and DNA damage response pathways, autophagy, establishment and reactivation from latency, interferon responses, immunity and vaccine development. Essential reading for everyone working with alphaherpesviruses and of interest to all virologists working on latent infections.
