Membrane Protein Structure Determination


Book Description

Membrane proteins, representing nearly 40% of all proteins, are key components of cells involved in many cellular processes, yet only a small number of their structures have been determined. Membrane Protein Structure Determination: Methods and Protocols presents many detailed techniques for membrane protein structure determination used today by bringing together contributions from top experts in the field. Divided into five convenient sections, the book covers various strategies to purify membrane proteins, approaches to get three dimensional crystals and solve the structure by x-ray diffraction, possibilities to gain structural information for a membrane protein using electron microscopy observations, recent advances in nuclear magnetic resonance (NMR), and molecular modelling strategies that can be used either to get membrane protein structures or to move from atomic structure to a dynamic understanding of a molecular functioning mechanism. Written in the highly successful Methods in Molecular BiologyTM series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Comprehensive and easy to use, Membrane Protein Structure Determination: Methods and Protocols serves as an ideal reference for scientists seeking to further our knowledge of these vital and versatile proteins as well as our overall understanding of the complicated world of cell biology.







Study of Bacteriorhodopsin in a Controlled Lipid Environment


Book Description

This book focuses on the study of how the properties of nanodiscs, such as lipid composition and size, influence the function of the embedding integral membrane protein, bacteriorhodopsin. The author performed systematic studies to show that the lipid composition and the charge of the hydrophobic head and the structure of hydrophilic tails affect the photocycle pathway of bacteriorhodopsin, which is closely associated with its proton-pumping activity. Furthermore, the author demonstrated a highly efficient method for extracting membrane proteins directly from the biological membrane, preserving protein conformation, function and essential native lipids. This book demonstrates optimization and sample preparation, and presents practical methods of preparing membrane protein-embedded nanodisc samples for biophysical studies, which benefit structural and functional studies in the field of membrane protein characterization, both.




Application of Nuclear Magnetic Resonance Spectroscopy to the Structure Determination of the Integral Membrane Proteins of the Mer Operon


Book Description

Efforts at elucidating the structural biology of membrane proteins represent an ongoing challenge to conventional methods of structure determination. The emergence of new methods for the measurement and application of orientational restraints have offered new avenues of pursuing the determination of membrane protein structures. Presented in this thesis is the evolution of experimental and computation methods necessary to extend NMR based structure determination methods to the polytopic mercuric ion transport proteins of the mer operon. Primary structural efforts are focused upon the bi-spanning protein, MerF, using solution-state NMR methods on protein reconstituted into isotropic and weakly aligned micelles and solid-state NMR methods on protein reconstituted into statically aligned bicelles. The application of the methods developed for MerF are applied to a tri-spanning chimeric protein, MerTf, to extend the NMR based methodology toward the structure determination of the principal mercuric ion transporter, MerT.




Protein NMR Techniques


Book Description

When I was asked to edit the second edition of Protein NMR Techniques, my first thought was that the time was ripe for a new edition. The past several years have seen a surge in the development of novel methods that are truly revolutionizing our ability to characterize biological macromolecules in terms of speed, accuracy, and size limitations. I was particularly excited at the prospect of making these techniques accessible to all NMR labs and for the opportunity to ask the experts to divulge their hints and tips and to write, practically, about the methods. I commissioned 19 chapters with wide scope for Protein NMR Techniques, and the volume has been organized with numerous themes in mind. Chapters 1 and 2 deal with recombinant protein expression using two organisms, E. coli and P. pastoris, that can produce high yields of isotopically labeled protein at a reasonable cost. Staying with the idea of isotopic labeling, Chapter 3 describes methods for perdeuteration and site-specific protonation and is the first of several chapters in the book that is relevant to studies of higher molecular weight systems. A different, but equally powerful, method that uses molecular biology to “edit” the spectrum of a large molecule using segmental labeling is presented in Chapter 4. Having successfully produced a high molecular weight target for study, the next logical step is data acquisition. Hence, the final chapter on this theme, Chapter 5, describes TROSY methods for stru- ural studies.




Experimental Approaches of NMR Spectroscopy


Book Description

This book describes the advanced developments in methodology and applications of NMR spectroscopy to life science and materials science. Experts who are leaders in the development of new methods and applications of life and material sciences have contributed an exciting range of topics that cover recent advances in structural determination of biological and material molecules, dynamic aspects of biological and material molecules, and development of novel NMR techniques, including resolution and sensitivity enhancement. First, this book particularly emphasizes the experimental details for new researchers to use NMR spectroscopy and pick up the potentials of NMR spectroscopy. Second, the book is designed for those who are involved in either developing the technique or expanding the NMR application fields by applying them to specific samples. Third, the Nuclear Magnetic Resonance Society of Japan has organized this book not only for NMR members of Japan but also for readers worldwide who are interested in using NMR spectroscopy extensively.




G Protein-Coupled Receptors in Drug Discovery


Book Description

The G protein-coupled receptors (GPCRs) and associated peripheral G proteins underpin a multitude of physiological processes. The GPCRs represent one of the largest superfamilies in the human genome and are a significant target for bioactive and drug discovery programs. It is estimated that greater than 50% of all drugs, including those in development, currently target GPCRs. Many of the characterized GPCRs have known ligands; however, approximately 20% of GPCRs are described as orphan GPCRs, apparent GPCRs that share the generic high-level structure charact- istic of GPCRs but whose endogenous ligand is not known. Therefore, it is expected that the field of GPCR drug discovery and development will greatly expand in the coming years with emphasis on new generations of drugs against GPCRs with unique therapeuticuseswhichmayincludedrugssuchasallostericregulators,inverseagonists, and identification of orphan GPCR ligands. AswelearnmoreaboutthemolecularsignalingcascadesfollowingGPCRactivation, we acquire a better appreciation of the complexity of cell signaling and as a result, also acquire a vast array ofnew molecularmethods toinvestigate these andother processes. Thegeneralaimofthisbookistoprovideresearcherswitharangeofprotocolsthatmay be useful in their GPCR drug discovery programs. It is also the basis for the devel- ment of future assays in this field. Therefore, the range of topics covered and the appropriate methodological approaches in GPCR drug discovery are reflected in this book. Itisinterestingtonotethatfuturedirectionsindrugdiscoverywillrequireinput and collaboration from a plethora of fields of research. As such, this book will likely be of interest to scientists involved in such fields as molecular biology, pharmacology, biochemistry, cellular signaling, and bio-nanotechnology.




NMR with Biological Macromolecules in Solution


Book Description

The book provides insights into the research of the Kurt Wüthrich laboratories from 1996-2020. During this time period, the technique of nuclear magnetic resonance (NMR) spectroscopy in solution went through several breakthroughs, while maturing into a standard method of structural biology. With the introduction of TROSY (transverse relaxation-optimized spectroscopy), the range of accessible molecular sizes was extended about thirty-fold, and efficient protein structure determination resulted from the demands of the structural genomics initiative. Applications in fundamental biology and biomedicine include studies of prion proteins and prion diseases (TSEs), the SARS-Corona virus proteome, trans-membrane signalling by G protein-coupled receptors (GPCRs), and signal transfer by pheromones.Key publications from the Kurt Wüthrich laboratories are placed in perspective, providing insights into new aspects of NMR spectroscopy in structural biology. In addition to methods development, this includes applications in diverse areas of biological research, such as prion proteins and their role in transmissible spongiform encephalopathies (TSEs), trans-membrane signal transfer by G protein-coupled receptors (GPCRs), structural characterization of the SARS-Corona virus proteome, metabolic-flux profiling in bacterial cultures, and signal transfers by pheromones.




NMR Spectroscopy of Membrane Proteins in Phospholipid Bilayers


Book Description

Solid-state nuclear magnetic resonance (NMR) spectroscopy is a powerful method for the study of membrane proteins under native environments. G protein-coupled receptors (GPCRs) are highly challenging integral membrane proteins that are often hard to study using the available biophysical techniques. Limited information about their structures and dynamics has been elucidated with x-ray crystallography as well as various biochemical techniques, such as Föster resonance energy transfer (FRET), and mutation studies. Obtaining site resolved NMR spectra for GPCRs can help to better understand their structures and behaviors. Here CXC-chemokine receptor 2 (CXCR2) is studied with various NMR tools, and the functional relevance of the obtained protein is verified with ligand binding assays as well as NMR. A comparison of CXCR2 interaction with two of its ligands: interleukin 8 and CXCL5 is also presented. At the same time, methods such as protein perdeuteration, and 1H detection were developed for the study of complex membrane proteins using the oriented-sample solid-state NMR technique. NMR developments are also made on the MerFTC chimeric protein, to help experiments for the more complex CXCR2. Combining various NMR techniques, optimized NMR spectra are presented, providing insights into the structure and function of the CXCR2 protein.