Relating Nmr Observables To Structure And Dynamics In Nucleic Acids And Proteins

Studying the structural dynamics of biomolecules is a challenging problem that has received much attention due to the recognition that structurally, most native biomolecules exist as ensemble of heterogenous states that inter-convert on the time scales rang- ing from nanoseconds to seconds. The implication of this is far reaching affecting all cellular process that rely on biomolecular recognition and interaction. Central to understanding how biomolecules function within this paradigm is the ability to determine structural ensembles of a target system. Equally important is the task of determining the rates of conformational transitions. Here I present application and validation of an approach that have the potential to characterize the structural en- sembles of highly flexible ribonucleic acids (RNAs) by combining molecular dynamics (MD) simulations and nuclear magnetic resonance (NMR) spectroscopy. As a special topic, a method is presented that can be used to extract rates of conformational transitions from MD simulations.

This book presents a critical assessment of progress on the use of nuclear magnetic resonance spectroscopy to determine the structure of proteins, including brief reviews of the history of the field along with coverage of current clinical and in vivo applications. The book, in honor of Oleg Jardetsky, one of the pioneers of the field, is edited by two of the most highly respected investigators using NMR, and features contributions by most of the leading workers in the field. It will be valued as a landmark publication that presents the state-of-the-art perspectives regarding one of today's most important technologies.

Volume 17 is the second in a special topic series devoted to modern techniques in protein NMR, under the Biological Magnetic Resonance series. Volume 16, with the subtitle Modern Techniques in Protein NMR , is the first in this series. These two volumes present some of the recent, significant advances in the biomolecular NMR field with emphasis on developments during the last five years. We are honored to have brought together in these volume some of the world s foremost experts who have provided broad leadership in advancing this field. Volume 16 contains - vances in two broad categories: I. Large Proteins, Complexes, and Membrane Proteins and II. Pulse Methods. Volume 17 contains major advances in: I. Com- tational Methods and II. Structure and Dynamics. The opening chapter of volume 17 starts with a consideration of some important aspects of modeling from spectroscopic and diffraction data by Wilfred van Gunsteren and his colleagues. The next two chapters deal with combined automated assignments and protein structure determination, an area of intense research in many laboratories since the traditional manual methods are often inadequate or laborious in handling large volumes of NMR data on large proteins. First, Werner Braun and his associates describe their experience with the NOAH/DIAMOD protocol developed in their laboratory.

The volume presents a survey of the research by Kurt Wthrich and his associates during the period 1965 to 1994. A selection of reprints of original papers on the use of NMR spectroscopy in structural biology is supplemented with an introduction, which outlines the foundations and the historical development of the use of NMR spectroscopy for the determination of three-dimensional structures of biological macromolecules in solution. The original papers are presented in groups highlighting protein structure determination by NMR, studies of dynamic properties and hydration of biological macromolecules, and practical applications of the NMR methodology in fields such as enzymology, transcriptional regulation, immunosuppression and protein folding.

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.

This book discusses the paradigm-shifting phenomenon of intrinsically disordered proteins (IDPs) and hybrid proteins containing ordered domains and functional IDP regions (IDPRs). The properties of IDPs and IDPRs are highly complementary to those deriving from the presence of a unique and well-defined three-dimensional fold. Ignored for a long time in high-resolution studies of proteins, intrinsic protein disorder is now recognized as one of the key features for a large variety of cellular functions, where structural flexibility presents a functional advantage in terms of binding plasticity and promiscuity and this volume explores this exciting new research. Recent progress in the field has radically changed our perspective to study IDPs through NMR: increasingly complex IDPs can now be characterized, a wide range of observables can be determined reporting on the structural and dynamic properties, computational methods to describe the structure and dynamics are in continuous development and IDPs can be studied in environments as complex as whole cells. This volume communicates the new exciting possibilities offered by NMR and presents open questions to foster further developments. Intrinsically Disordered Proteins Studied by NMR Spectroscopy provides a snapshot to researchers entering the field as well as providing a current overview for more experienced scientists in related areas.

NMR chemical shifts have an extremely high information content on the behaviour of macromolecules, owing to their non-trivial dependence on myriads of structural and environmental factors. Although such complex dependence creates an initial barrier for their use for the characterisation of the structures of protein and nucleic acids, recent developments in prediction methodologies and their successful implementation in resolving the structures of these molecules have clearly demonstrated that such barrier can be crossed. Furthermore, the significance of chemical shifts as useful observables in their own right has been substantially increased since the development of the NMR techniques to study low populated 'excited' states of biomolecules. This work is aimed at increasing our understanding of the multiple factors that affect chemical shifts in proteins and nucleic acids, and at developing high-quality chemical shift predictors for atom types that so far have largely escaped the attention in chemical shift restrained molecular dynamics simulations. A general approach is developed to optimise the models for structure-based chemical shift prediction, which is then used to construct CH3Shift and ArShift chemical shift predictors for the nuclei of protein side-chain methyl and aromatic moieties. These results have the potential of making a significant impact in structural biology, in particular when taking into account the advent of recent techniques for specific isotope labelling of protein side-chain atoms, which make large biomolecules accessible to NMR techniques. Through their incorporation as restraints in molecular dynamics simulations, the chemical shifts predicted by the approach described in this work create the opportunity of studying the structure and dynamics of proteins in a wide range of native and non-native states in order to characterise the mechanisms underlying the function and dysfunction of these molecules.

Provided here are the latest techniques of NMR as applied to the study of proteins, carbohydrates and nucleic acids. The first chapters are devoted to an introduction to NMR and parameters related to molecular structure and molecular interactions. NMR experiments from basic 1D to 2D, 3D and 4D, used in combination with isotopically labelled molecules, are described and a general strategy is presented for biomacromolecular structure determination. Subsequent chapters deal with more advanced principles and techniques and their applications to structural and dynamic processes involving biomacromolecules in solution. Advanced results on peptide, protein, oligosaccharide and nucleic acid structure and recognition are presented.

Proteins are essential for all known forms of life and in many lethal diseases protein failure is the cause of the disease. To understand proteins and the processes they are involved in, it is valuable to know their structures as well as their dynamics and interactions. The structures may not be directly inspected because proteins are too small to be visible in a light microscope, which is why indirect methods such as nuclear magnetic resonance (NMR) spectroscopy have to be utilized. This method provides atomic information about the protein and, in contrast to other methods with similar resolution, the measurements are performed in solution resulting in more physiological conditions, enabling analysis of dynamics. Important dynamical processes are the ones on the millisecond timeframe, which may contribute to interactions of proteins and their catalysis of chemical reactions, both of significant value for the function of the proteins. To better understand proteins, not only do we need to study them, but also develop the methods we are using. This thesis presents four papers about improved NMR techniques as well as a fifth where the kinase domain of ephrinB receptor 2 (EphB2) has been studied regarding the importance of millisecond dynamics and interactions for the activation process. The first paper presents the software COMPASS, which combines statistics and the calculation power of a computer with the flexibility and experience of the user to facilitate and speed up the process of assigning NMR signals to the atoms in the protein. The computer program PINT has been developed for easier and faster evaluation of NMR experiments, such as those that evaluate protein dynamics. It is especially helpful for NMR signals that are difficult to distinguish, so called overlapped peaks, and the soft- ware also converts the detected signals to the indirectly measured physical quantities, such as relaxation rate constants, principal for dynamics. Next are two new versions of the Carr-Purcell-Maiboom-Gill (CPMG) dispersion pulse sequences, designed to measure millisecond dynamics in a way so that the signals are more separated than in standard experiments, to reduce problems with overlaps. To speed up the collection time of the data set, a subset is collected and the entire data set is then reconstructed, by multi-dimensional decomposition co-processing. Described in the thesis is also a way to produce suitably labeled proteins, to detect millisecond dynamics at C? positions in proteins, using the CPMG dispersion relaxation experiment at lower protein concentrations. Lastly, the kinase domain of EphB2 is shown to be more dynamic on the millisecond time scale as well as more prone to interact with itself in the active form than in the inactive one. This is important for the receptor function of the protein, when and how it mediates signals. To conclude, this work has extended the possibilities to study protein dynamics by NMR spectroscopy and contributed to increased understanding of the activation process of EphB2 and its signaling mechanism.