Biological Magnetic Resonance – serie

In the past ten years or so, biological magnetic resonance (NMR and ESR) has fully blossomed and become highly branched. In the 1970s and earlier, a practitioner in biological magnetic resonance was using virtually all of the available methods suitable for his research, with the latter covering a diverse range of systems. Today, the focus of an individual laboratory is actually much narrower, with respect to both the methods and the systems investigated. Thus, those who investigate protein structure by multi­ dimensional NMR spectroscopy do not usually engage in studies involving in vivo spectroscopy. The conferences on biological magnetic resonance now have parallel sessions rather than the single, common session of earlier days. Moreover, topical meetings are becoming more frequent. Therefore, this and future volumes of our series will also focus on specific topical areas. We are proud to present Volume 10 of our series. It focuses on Carbohydrates and Nucleic Acids. In an extensive chapter, Kamerling and Vliegenthart use oligosaccharide-alditols released from mucin-type- glycoproteins to illustrate the power of proton NMR spectroscopy in the determination of carbohydrate structure. Wemmer gives a detailed coverage of the arsenal of modern NMR methods now available for structural studies of nucleic acids. Forthcoming volumes will focus on In Vivo Spectroscopy and Protein Structure. As always, we are anxious to get feedback from the readers and hear their comments and suggestions. Lawrence J.

In vivo nuclear magnetic and electron spin resonance spectroscopy is concerned, inter alia, with the noninvasive observation of metabolic changes in living systems, including animals and humans. Typically, the physiologi­ cal (or pathological) state of an organ or tissue is monitored. This multi­ faceted approach was developed during the 1980s. It is still a research technique, but will undoubtedly become a clinical tool. We are proud to present this volume (the eleventh of our series) in which some of the pioneers in this area summarize their contributions and review related literature. Bolinger and Lenkinski describe a variety of localization methods suitable for clinical applications of NMR spectroscopy. Schleich, Caines, and Rydzewski summarize their contributions to approaches involving off-resonance rotating frame relaxation and critically compare these with other NMR techniques that may yield similar information. Chang and James outline their approach and share their experience with the technical aspects 1 31 of H and P NMR spectroscopy and spatially localized spectroscopy in studies of brain ischemia. Sodium plays an important role in living systems, a key aspect being the large gradient between intra- and extracellular concentrations of sodium that is maintained by a variety of transport mechanisms. Miller and Elgavish give us a comprehensive review of an important research tool in this 23 area- Na NMR spectroscopy as aided by shift reagents.

Published as a companion to Volume 12, the current volume presents the latest advances in electron paramagnetic resonance of iron proteins, metalloproteins, and free radicals. The book features a diskette containing programs for iron ERP spectral simulation and ENDOR analyses.

We present here the second issue devoted entirely to the spin-labeling technique as part of Biological Magnetic Resonance. Volume 14 commemorates a modifi- tion in our editorial policy with the retirement of my esteemed coeditor, Jacques Reuben. From thisjuncture into the future, each issue will focus on some special topic in magnetic resonance. Each volume will be organized in most cases by guest editors, for example forthcoming issues will address the following topics: in vivo magnetic resonance (P. Robitaille and L. J. Berliner, eds. ) Modern techniques in proton NMR ofproteins (R. Krishna and L. J. Berliner, eds. ) Instrumental techniques of EPR (C. Bender and L. J. Berliner, eds. ) Thecurrent volume, Spin Labeling: The NextMillennium, presents an excellent collection of techniques and applications that evolved during the past decade since the last volume, volume 8 (1989). Someobvious omissions, such as multiquantum EPR and very high-frequency FT-ESR were unfortunately not possible for this volume. Perhaps they will appear in Spin Labeling: 2001. Lastly it is a pleasure to honor two scientists whose contributions were both pioneering and pivotal to the spin label technique: Professor Eduard G. Rozantsev (Moscow), whose synthetic feats in nitroxyl chemistry set the broad stage for a versatile catalog of labels; and Professor Harden M. McConnell, last year's Int- national ESR (EPR) Society Gold Medalist, who conceived and developed the spin label technique to address many biological problems (proteins, enzymes, m- branes, cells, immune response, etc. ). Lawrence J.

This volume constitutes a compilation of the latest experiments and theories on a rapidly evolving and maturing field in MRI/MRS, which is the use of the stable isotope 13-C. The 13-C is used to probe the chemistry, mechanism, and function in living systems. All the chapters are written by experts in the field who discuss topics such as `Tracer Theory and the Suitability of 13-C NMR', `Applications of 13-C to Studies of Human Brain Metabolism', etc.

Volume 16 marks the beginning of a special topic series devoted to modern techniques in protein NMR, under the Biological Magnetic Resonance series. This volume is being followed by Volume 17 with the subtitle Structure Computation and Dynamics in Protein NMR. Volumes 16 and 17 present some of the recent, significant advances in biomolecular NMR field with emphasis on developments during the last five years. We are honored to have brought together in these volumes some of the world’s foremost experts who have provided broad leadership in advancing this field. Volume 16 contains advances in two broad categories: the first, Large Proteins, Complexes, and Membrane Proteins, and second, Pulse Methods. Volume 17, which will follow covers major advances in Computational Methods, and Structure and Dynamics. In the opening chapter of Volume 16, Marius Clore and Angela Gronenborn give a brief review of NMR strategies including the use of long range restraints in the structure determination of large proteins and protein complexes. In the next two chapters, Lewis Kay and Ron Venters and their collaborators describe state-of-t- art advances in the study of perdeuterated large proteins. They are followed by Stanley Opella and co-workers who present recent developments in the study of membrane proteins. (A related topic dealing with magnetic field induced residual dipolar couplings in proteins will appear in the section on Structure and Dynamics in Volume 17).

Represents significant advances in the biomolecular NMR field, this text puts emphasis on developments during the last five years since 1993/4. The book brings together experts who have provided broad leadership in advancing the field. Volume 16 is devoted to topics on biomacromolecules and pulse methods. This volume covers important advances in the study of large proteins and protein complexes, methods involving perdeuterated large proteins, membrane proteins, advances in pulse schemes for spin decoupling and for the measurement of coupling constants and torsion angle constraints.

Distance measurements in biological systems by EPR The foundation for understanding function and dynamics of biological systems is knowledge of their structure. Many experimental methodologies are used for determination of structure, each with special utility. Volumes in this series on Biological Magnetic Resonance emphasize the methods that involve magnetic resonance. This volume seeks to provide a critical evaluation of EPR methods for determining the distances between two unpaired electrons. The editors invited the authors to make this a very practical book, with specific numerical examples of how experimental data is worked up to produce a distance estimate, and realistic assessments of uncertainties and of the range of applicability, along with examples of the power of the technique to answer biological problems. The first chapter is an overview, by two of the editors, of EPR methods to determine distances, with a focus on the range of applicability. The next chapter, also by the Batons, reviews what is known about electron spin relaxation times that are needed in estimating distances between spins or in selecting appropriate temperatures for particular experiments. Albert Beth and Eric Hustedt describe the information about spin-spin interaction that one can obtain by simulating CW EPR line shapes of nitroxyl radicals. The information in fluid solution CW EPR spectra of dual-spin labeled proteins is illustrated by Hassane Mchaourab and Eduardo Perozo.

This book is divided into three major sections dealing with significant recent advances in the study of large proteins in solution and solid state, structure refinement and screening of bioactive ligands. Among others, it covers developments such as TROSY, segmental isotope labeling of proteins, hydrogen bond scalar couplings and structure refinement based on residual dipolar couplings. Volume 20 is the third in a special topic series devoted to the latest developments in protein NMR under the "Biological Magnetic Resonance" series. The previous two volumes were 16 (Modern Techniques in Protein NMR, 1998), and 17 (Structure Computation and Dynamics in Protein NMR, 1999). Volume 20 brings together some of the world's foremost experts who have provided broad leadership in advancing the protein NMR field.

A textbook on a relatively new subject in biomedical electron spin resonance. While a few chapters have appeared in special topics volumes in this series, this book covers the principles and theory, instrumentation, as well as the latest applications at the time of its writing. The authors are experts in their fields. The book is divided into two major sections dealing with theory and instrumentation, and aspects of biochemistry, in vitro and in vivo applications. A significant amount of detail is devoted to clinical applications and the problems and pitfalls encountered in in vivo spectroscopy and imaging.

Electron magnetic resonance spectroscopy is undergoing something akin to a renaissance that is attributable to advances in microwave circuitry and signal processing software. EPR: Instrumental Methods is a textbook that brings the reader up to date on these advances and their role in providing better experimental techniques for biological magnetic resonance. Chapters in this book guide the reader from basic principles of spectrometer design through the advanced methods that are providing new vistas in disciplines such as oximetry, imaging, and structural biology. Key Features: - Spectrometer design, particularly at low frequencies (below X-band), Design of spectrometer components unique to ENDOR and ESEEM, Optimization of EMR spectrometer sensitivity spanning many octaves, Algorithmic approach to spectral parameterization, Application of Fourier Methods to polymer conformation, oximetry, and imagin.

Very High Frequency (VHF) ESR/EPR focuses on a new area of electron spin resonance spectroscopy that has blossomed during the past decade. This textbook both highlights the state-of-the-art of this field while covering the full scope of VHF EPR in a single volume. The topics were chosen to cover areas in which VHF EPR seems to be especially productive, as well as critical new technical developments. The contributors of the book are leaders in their fields. They emphasize the need for VHF EPR, describe results that could only be achieved with VHF EPR, and discuss the further potential of this evolving field. This volume provides information that will be useful for many years, focusing on what advantages and benefits one may expect from VHF EPR. Key Features:

Biomedical EPR – Part A focuses on applications of EPR spectroscopy in the areas of free radicals, metals, medicine, and physiology. The book celebrates the 70th birthday of Prof. James S. Hyde, Medical College of Wisconsin, and his contributions to this field. Chapters are written to provide introductory material for new-comers to the field which lead into up-to-date reviews that provide perspective on the wide range of questions that can be addressed by EPR. Key Features:Free Radicals in Medicine Radicals in vivo and in Model Systems, and their Study by Spin Trapping In vivo EPR, including Oximetry and Imaging Time Domain EPR at Radio Frequencies EPR of Copper Complexes: Motion and Frequency Dependence Time Domain EPR and Electron Spin Echo Envelope Modulation

Biomedical EPR – Part B focuses on applications of EPR techniques and instrumentation, with applications to dynamics. The book celebrates the 70th birthday of Prof. James S. Hyde, Medical College of Wisconsin, and his contributions to this field. Chapters are written to provide introductory material for new-comers to the field that lead into up-to-date reviews that provide perspective on the wide range of questions that can be addressed by EPR. Key Features:EPR Techniques including Saturation Recovery, ENDOR, ELDOR, and Saturation Transfer Instrumentation Innovations including Loop Gap Resonators, Rapid Mixing, and Time Locked Sub-Sampling Motion in Biological Membranes Applications to Structure Determination in Proteins Discussion of Trends in EPR Technology and Prognosis for the Future

Spectroscopic methods are not only important as an analytical tool, they also provide information about fundamental physical and chemical properties of molecules, the molecular and electronic structure, and the dynamic behaviour of molecules. Starting from a comprehensive quantum mechanical description, ESR Spectroscopy in Membrane Biophysics introduces the optical (IR, Raman, UV/Vis, CD, fluorescence and laser spectroscopy) and magnetic resonance (1D and 2D-NMR, ESR) techniques. ESR Spectroscopy in Membrane Biophysics is a timely review of the increasing interest in using spin-label ESR as an alternative structural technique for NMR or X-ray diffraction. It is aimed at training an audience to learn ESR spectroscopy to determine membrane protein structures, conformational dynamics and protein-lipid interaction.

Electron magnetic resonance in the time domain has been greatly facilitated by the introduction of novel resonance structures and better computational tools, such as the increasingly widespread use of density-matrix formalism. This second v- ume in our series, devoted both to instrumentation and computation, addresses - plications and advances in the analysis of spin relaxation time measurements. Chapters 1 deals with the important problem of measuring spin relaxation times over a broad temporal range. The author, Dr. Sushil Misra, has worked on a wide variety of solutions to problems in this area, with respect to both experimental and theoretical aspects, and Chapter 1 summarizes much of his recent work, which was enhanced by a fruitful collaboration with the late Professor Jacques Pescia. Chapter 2 presents solutions to the problem of measuring short spin relaxation times. Again, in collaboration and tribute to the late Jacques Pescia's laboratory, part of the chapter represents a translation of the amplitude modulation technique section from a doctoral thesis by Robert Lopez in 1993 to The Paul Sabatier U- versity. Experimental data that appeared in the original thesis are placed at the end of subsections that correspond to the described technique. Chapter 3 takes up the problem of multi-frequency ENDOR and ESEEM, and illustrates how small stepwise increments of spectrometer operating parameters can enable one to better determine spin-Hamiltonian parameters via a graphical analysis.

From the early examples of what was to be called MRI, extending the te- nique to higher fields than those of less than 0. 1 T used in the first large-volume instruments was a goal, but the way there was unclear. The practical success of large superconducting magnets was a surprise, and the astonishment continued as they developed fields from 0. 3 T to 0. 6 T to 1. 5 T, and even more, up to the now common 3T systems, and a few 4T machines, and now to about 100 times the fields used in the first medium- and large-bore devices. In the early machines, low radiofrequencies of 4 MHz or so meant that RF coil designs were simple (even inexperienced undergraduates could design and build such circuits with little knowledge of more than DC electrical circuits), and the forces on gradient coils were small. The effects of magnetic susceptibility in- mogeneity in and around the object being imaged were negligible, and RF penet- tion depths were not a problem for human-scale samples. Everything began to change as higher fields and higher frequencies came into use, and the earlier idyllic simplicities began to seem quaint. The trend continued, however, driven by the increased signal-to-noise ratios and the resultant higher resolutions and speed available, and sophisticated engineering became more and more essential, not only for magnets but for gradient systems and radiofrequency transmitters and receivers, but also for better software for modeling and correcting distortions.

Metalloproteins comprise approximately 30% of all known proteins, and are involved in a variety of biologically important processes, including oxygen transport, biosynthesis, electron transfer, biodegradation, drug metabolism, proteolysis, and hydrolysis of amides and esters, environmental sulfur and nitrogen cycles, and disease mechanisms. EPR spectroscopy has an important role in not only the geometric structural characterization of the redox cofactors in metalloproteins but also their electronic structure, as this is crucial for their reactivity. The advent of x-ray crystallographic snapshots of the active site redox cofatcors in metalloenzymes in conjunction with high-resolution EPR spectroscopy has provided detailed structural insights into their catalytic mechanisms. This volume was conceived in 2005 at the Rocky Mountain Conference on Analytical Chemistry (EPR Symposium) to highlight the importance of highresolution EPR spectroscopy to the structural (geometric and electronic) characterization of redox active cofactors in metalloproteins.We have been fortunate to have enlisted internationally recognized experts in this joint venture to provide the scientific community with an overview of high-resolution EPR and its application to metals in biology.This volume, High-Resolution EPR: Applications to Metalloenzymes and Metals in Medicine, covers high-resolution EPR methods, iron proteins, nickel and copper enzymes, and metals in medicine. An eloquent synopsis of each chapter is provided by John Pilbrow in the Introduction which follows. A CD containing pdf files of all the chapters in this volume, some of which contain color figures, can be found attached to the inside back cover. A second volume, Metals in Biology: Applications of High-Resolution EPR to Metalloenzymes, will appear later this year covering the complement of other metalloproteins. One of the pioneers in the development of pulsed EPR and its application to metalloproteins was Arthur Schweiger, whose contribution we include in this volume. Unfortunately, he passed away suddenly during the preparation of this volume.The editors and coauthors are extremely honored to dedicate this volume to the memory of Arthur Schweiger in recognition of his technical advances and insights into pulsed EPR and its application to metalloproteins. Arthur was extremely humble and treated everyone with equal respect.He was a gifted educator with an ability to explain complex phenomena in terms of simple intuitive pictures, had a delightful personality, and continues to be sadly missed by the community. It is an honor for the editors to facilitate the dissemination of these excellent contributions to the scientific community. Suggestions for future volumes are always appreciated.

Very High Frequency (VHF) ESR/EPR focuses on a new area of electron spin resonance spectroscopy that has blossomed during the past decade. This textbook both highlights the state-of-the-art of this field while covering the full scope of VHF EPR in a single volume. The topics were chosen to cover areas in which VHF EPR seems to be especially productive, as well as critical new technical developments. The contributors of the book are leaders in their fields. They emphasize the need for VHF EPR, describe results that could only be achieved with VHF EPR, and discuss the further potential of this evolving field. This volume provides information that will be useful for many years, focusing on what advantages and benefits one may expect from VHF EPR. Key Features: -History of Very High Frequency EPR, -Principles of High-Field EPR, Instrumentation and Resonators for Quasioptical EPR, -Applications to Photosynthesis, Protein Structure, Molecular Dynamics, Metal Sites in Proteins, Transition Metal Centers, Small Inorganic Models and Spin Labels in Membranes, -Pulse High Frequency EPR, Time-Resolved High Frequency and Multifrequency EPR, -High Frequency ESEEM and ENDOR.

Biomedical EPR -- Part A focuses on applications of EPR spectroscopy in the areas of free radicals, metals, medicine, and physiology. The book celebrates the 70th birthday of Prof. James S. Hyde, Medical College of Wisconsin, and his contributions to this field. Chapters are written to provide introductory material for new-comers to the field which lead into up-to-date reviews that provide perspective on the wide range of questions that can be addressed by EPR. Key Features:Free Radicals in Medicine Radicals in vivo and in Model Systems, and their Study by Spin Trapping In vivo EPR, including Oximetry and Imaging Time Domain EPR at Radio Frequencies EPR of Copper Complexes: Motion and Frequency Dependence Time Domain EPR and Electron Spin Echo Envelope Modulation

Biomedical EPR -- Part B focuses on applications of EPR techniques and instrumentation, with applications to dynamics. The book celebrates the 70th birthday of Prof. James S. Hyde, Medical College of Wisconsin, and his contributions to this field. Chapters are written to provide introductory material for new-comers to the field that lead into up-to-date reviews that provide perspective on the wide range of questions that can be addressed by EPR. Key Features:EPR Techniques including Saturation Recovery, ENDOR, ELDOR, and Saturation Transfer Instrumentation Innovations including Loop Gap Resonators, Rapid Mixing, and Time Locked Sub-Sampling Motion in Biological Membranes Applications to Structure Determination in Proteins Discussion of Trends in EPR Technology and Prognosis for the Future

Electron magnetic resonance in the time domain has been greatly facilitated by the introduction of novel resonance structures and better computational tools, such as the increasingly widespread use of density-matrix formalism. This second v- ume in our series, devoted both to instrumentation and computation, addresses - plications and advances in the analysis of spin relaxation time measurements. Chapters 1 deals with the important problem of measuring spin relaxation times over a broad temporal range. The author, Dr. Sushil Misra, has worked on a wide variety of solutions to problems in this area, with respect to both experimental and theoretical aspects, and Chapter 1 summarizes much of his recent work, which was enhanced by a fruitful collaboration with the late Professor Jacques Pescia. Chapter 2 presents solutions to the problem of measuring short spin relaxation times. Again, in collaboration and tribute to the late Jacques Pescia's laboratory, part of the chapter represents a translation of the amplitude modulation technique section from a doctoral thesis by Robert Lopez in 1993 to The Paul Sabatier U- versity. Experimental data that appeared in the original thesis are placed at the end of subsections that correspond to the described technique. Chapter 3 takes up the problem of multi-frequency ENDOR and ESEEM, and illustrates how small stepwise increments of spectrometer operating parameters can enable one to better determine spin-Hamiltonian parameters via a graphical analysis.

We present this special topics volume on an area which has not received thorough coverage for over 12 years. Spin Labeling: Theory and Applications represents a complete update on new theoretical aspects and applications of the spin-label method. In the "line-shape theory" sections, we are especially pleased to include an IBM-compatible diskette supplied by David Schneider and Jack Freed which contains fast, accurate, ready-to-use software for slow-motion simulations. Barney Bales discusses inhomogeneous broadening phenomena in detail. Several developments in techniques and interpretation in saturation transfer spectroscopy have appeared since the publica­ tion of Spin Labeling II: Theory and Applications (L. J. Berliner, ed., Academic Press, 1979). We have included an up-to-date chapter on spin-label applications by M. A. Hemminga and P. A. de Jager. By incorporating 15N and deuterium into nitroxide spin labels, several unique advantages are derived in line-shape analysis. Albert Beth and Bruce Robinson have contributed a detailed chapter on the analysis of these labels in the slow-motion regime while Jane Park and Wolfgang Trommer present the advantages for specific biochemical examples in our "applications" section. Derek Marsh's contri­ bution on spin-label spectral analysis may be regarded as a summary chapter which touches on several of the detailed spectral analysis methods described in the earlier chapters.

We are again proud to present an excellent volume of contemporary topics in NMR and EPR to the biological community. The philosophy behind the volume and the presentation of each chapter remains at the high level reflected in our earlier volumes: to be current, pedagogical, and critical. The first chapters, as always, address a subject related to in-vivo biology. Gabby Elgavish addresses NMR spectroscopy of the intact heart. lain Campbell and colleagues present a state-of-the-art description of NMR methods for probing enzyme kinetics in intact cells and tissues. Klaus Mobius and Wolfgang Lubitz have produced a thorough review of the principles and applications of ENDOR spectroscopy in photobiology and biochemistry including discussions of liquid and solid state ENDOR as well as CIDEP-enhanced ENDOR. The final chapter by Hans Vogel and Sture Forsen addresses a contemporary problem in inorganic biochemistry, namely cation binding to calcium binding proteins. We are pleased to announce that a special forthcoming volume will be devoted entirely to the subject of "Spin Labeling: Theory and Applications (3rd compendium)." A substantial degree of progress has occurred in this important area of ESR in biology since the last treatise on the subject in 1979. Lastly, we acknowledge our colleagues in the field who continue to support this excellent series both as subscribers and contributors. We pledge to continue servicing the community as long as the need exists.

We are proud to present Volume 3 of Biological Magnetic Resonance, a series that has met with praise from the scientific community. This volume covers the new applications of various multiple irradia- tion techniques to the NMR of biomolecules; the chapter of Keller and Wuthrich describes much of the technique and its applications to hemo- proteins. The ESR of some hemoproteins in the single crystal is described by Chien and Dickinson, who also include discussions of techniques and methods for single-crystal ESR of paramagnetically intrinsic and spin- labeled protein crystals. Mims and Peisach describe the latest applications and results in electron spin echo spectroscopy of several metalloproteins. Two ESR spin probe techniques are reviewed. Chasteen describes the methods and applications of vanadyl(JV) to several systems. Ohnishi and Tokutomi describe studies of phase separations in mixed and model mem- branes by the nitroxide spin probe technique. We have been successful in continuing to provide topics that are timely and experimentally informative with a heavy emphasis on biolo- gically relevant applications.We thank our colleagues in the scientific com- munity for their suggestions on future coverage-we will remain receptive to future suggestions and comments on this series. A tentative topic list for forthcoming volumes is given on the following pages.

Electron magnetic resonance spectroscopy is undergoing something akin to a renaissance that is attributable to advances in microwave circuitry and signal processing software. EPR: Instrumental Methods is a textbook that brings the reader up to date on these advances and their role in providing better experimental techniques for biological magnetic resonance. Chapters in this book guide the reader from basic principles of spectrometer design through the advanced methods that are providing new vistas in disciplines such as oximetry, imaging, and structural biology. Key Features: Spectrometer design, particularly at low frequencies (below X-band), Design of spectrometer components unique to ENDOR and ESEEM, Optimization of EMR spectrometer sensitivity spanning many octaves, Algorithmic approach to spectral parameterization, Application of Fourier Methods to polymer conformation, oximetry, and imaging.

In Vivo EPR (ESR) is a textbook on this relatively new subject in biomedical electron spin resonance. While a few chapters have appeared in special topics volumes in this series, this book covers the principles and theory, instrumentation as well as the latest applications at the time of its writing. The authors are world-renowned experts and pioneers in their fields. This book is divided into two major sections dealing with theory and instrumentation, and aspects of biochemistry, in vitro and in vivo applications. A significant amount of detail is devoted to clinical applications and the problems and pitfalls encountered in in vivo spectroscopy and imaging. Key Features: -History of In Vivo EPR, -Principles of Imaging-Theory and Instrumentation, -Time-domain Radio Frequency EPR Imaging, -The Measurement of Oxygen In Vivo Using In Vivo EPR Techniques, -Potential Medical (Clinical) Applications of EPR, -Combining NMR and EPR/ESR for In Vivo Experiments.

The first of a two volume set, Volume 12 provides a long-awaited compilation of NMR theory to paramagnetic molecules. International experts report the latest developments in NMR methodology as applied to strongly relaxed and shifted resonances, detail the theoretical aspects of paramagnetic shift and relaxation, and discuss the interpretive bases of these molecular properties in relation to the structure and function of various paramagnetic molecules.