Molecular Biology, Biochemistry and Biophysics Molekularbiologie, Biochemie und Biophysik – serie

The objective of the new series, "Molecular Biology, Biochemistry and Biophysics", of which this brochure forms the first volume, is to produce more than another compilation of data. It is hoped that the new series will help the individual "specialist" keep abreast of important developments in the natural sciences at the molecular and subcellular level in fields complementary to his own. The predominant aim is not so much to increase the ever-growing body of information in an encyclopedic fashion but rather to give, in addition to a well­ rounded factual presentation of subjects which have reached a degree of maturation, a leitmotiv developed by the individual authors from a more personal point of view. The reader should thus be able to use these mono­ graphs not only for acquisition of knowledge but as a source of further motiva­ tion in his own work. This latter and more consequential aim of the monograph series is one of the reasons for presenting here a most unusual talk which should enable the reader to sit back and view his own efforts in the context of science and creative attempts as a whole. The lecture is the virtually unknown inaugural address of the Dutch physical chemist JACOBUS HENRICUS VAN'T HOFF. As is shown in his short biography presented on pages 3 and 4 the principal thoughts of the molecular biologist of today are akin to his own and he clearly recognized the universality of molecular life processes.

Among terrestrial plants the vascular plants are the largest and the most con­ spicuous. Because of the presence of lignified supporting and conducting tissues such as xylem, terrestrial vascular plants can develop large upright forms. Composed mainly of xylem tissue, the stems of trees are characterized by elongated cells with thickened walls, impregnated by lignin. Diagrams of xylem cells (vessels, tracheids and fibers) can be seen in textbooks of plant anatomy (e. g. ESAU, 1953). A cross section of xylem tissue is shown in the section of this volume written by Professor FREUDENBERG (Fig. 1, p. 98). In general the occurrence of lignin in the plant kingdom is associated with the presence of these cells which comprise xylem. Thus lignin is found in vascular plants such as lycopods, ferns, gymnosperms and angiosperms, whereas it is absent from simple plants such as fungi, and from all other organisms. The mosses are an exceptional group which do not have the cells characteristic of xylem tissue but which contain lignin-like materials. These "moss lignins" have been discussed by Professor FREUDENBERG in this volume, and some doubts have been expressed as to whether or not they are true lignins (FR. * pp. 113-114). Work on the chemistry of lignin indicates that it is a polymer derived from the phenylpropanoid compound, coniferyl alcohol and related alcohols.

This monograph is neither a historical outline of the development of the concepts of protein biosynthesis and the structure and functions of the ribosomes, nor an exhaustive survey of the literature on these questions. The monograph is based upon an analysis of the modern trends in this field. The purpose of the monograph was to formulate more or less generalized representations of the structure and" function of the ribosome, as we envision it at the present day. It may be that this attempt is premature for a number of reasons, and the concepts outlined here will very soon be revised. Nonetheless, despite this risk, we believe it to be advisable to undertake this attempt for the following reasons: firstly, the undertaken analysis could aid in the comprehension of the substantial mass of extremely scattered experimental data on the ribosomes presently available; secondly, in any event, even if most of the concepts outlined rapidly become obselete, they can still serve as a stimulus for a whole series of experiments; and thirdly, we hope that some of the concepts outlined will still remain essentially correct and relatively stable. In view of the aforementioned, we should make the following reservations. First of all, we made no attempt to cite all the literature on the problems discussed, but considered it sufficient to illustrate the various premises with one or several sample references.

This book deals with energetics of transport processes, largely expressed in terms of the thermodynamics of irreversible pro­ cesses. Since at the present time too little is known about the molecular mechanism of transport, the present treatment is based largely on hypothetical models. Care has been taken, however, to define the crucial features of these models as generally as pos­ sible, so that the equations do not depend too much on hypotheti­ cal details. Accordingly, most equations, though developed on the basis of a mobile carrier (ferryboat) model, should apply equally to a conformational model, with an appropriate reinterpretation of the symbols. To better elucidate the essentials, the models are greatly simplified by special assumptions. Maximally, only two flows are assumed to be present in each model at one time: e. g. , two solute flows, the flow of solvent and of one solute, the flow of solvent and of heat. The simplifying assumptions may often be unreal. Hence the equations should not be applied un­ critically to actual mechanisms. They may at best serve as a ba­ sis on which the more appropriate equations may be developed. The book is not designed to give a complete kinetic analysis of the transport processes described. The kinetic equations are kept to the minimum required to describe the model concerned and to relate it to the corresponding thermodynamic equations. The in­ tention is to stress the close relationship between bioosmotic (transport) and biochemical processes in metabolism.

It has long been known that every individual has a large number of antibodies of different specificities. Antibodies are gammaglobulins, and protein structure in cells is genetically determined. The extreme multiplicity of structure of the combining sites of antibodies relative to the degree of multiplicity generated by ordinary genetic mechanisms is a fascinating problem of bio-medical importance. The functional heterogeneity of reactions mediated by immunoglobulins-is remarkable, ranging from protection against life-threatening toxins and microbes to the production of laryngeal edema leading to suffocation and death from anaphylaxis. An approach to the understanding of immunoglobulin polymorphism based upon "a knowledge of genetic markers of immunoglobulin structure is not biased by the question of whether or not this polymorphism is related to combining site diversity. Though several recent reviews of the multifacetted problems related to immuno­ globulins are available, it was decided to publish this survey in the belief that know­ ledge of the genetic markers of immunoglobulins prqvides such information about immunoglobulin differentiation and its control as cannot be obtained from other sources. Several of the human genetic im~unoglobulin markers are well understood at the molecular level. The Gm system may serv~ as a model for other immuno­ genetic systems. The published data on the human immunoglobulin factors are widely scattered in journals of different perspectives. There is a need for a systematic presentation of these data and for their critical evaluation.

In recent years bacteriocins, especially colicins, have become widely known to molecular biologists as proteins with peculiar ways of killing bacteria. These same bacteriocins have been known for a long time to bacteriology for their unusual activity spectra and enormous variety. In this monograph I have attempted to bring together our detailed knowledge of those few bacteriocins which have already re­ ceived attention from molecular biologists, and our less detailed hut extensive knowledge of the variety of bacteriocins which exist. The field has been reviewed in whole or in part, by several authors [FREDERICQ, 1957, 1964, 1965 (2); IVANOVICS, 1962; HAMON, 1965; REEVES, 1965 (2)]. These reviews have been very useful to the author, and readers will find further references in them, and sometimes alternative viewpoints. We have already referred to bacteriocins as proteins, and in doing so have ex­ cluded many more complex antibacterial agents which resemble bacteriophages or their tails. In the author's view, these phage-like particles are probably not bacterio­ cins, but many authors include them within the definition; the more restrictive de­ finition used here has meant omitting discussion of some excellent studies on what the present author would term defective bacteriophages. In the first chapter we look at the discovery of bacteriocins and an outline of their classification. With this background we can discuss in Chapters 2 to 6 the chemistry, genetics and mode of action of the more intensively studied bacteriocins.

A century has already passed since FRIEDRICH MIESCHER, working at Strasbourg and Basel, began his study of protamine, one of the basic nuclear proteins of cells. It was first established by KOSSEL that protamine represents the simplest known protein. In the conviction that research into the nature of protamine would shed light on that of other typical proteins, a group of researchers in Germany followed MIESCHER and laid the foundations of protein chemistry. A general view of prot­ amines was thus built up by KOSSEL, working at Strasbourg, Berlin, Marburg an der Lahn, and Heidelberg, FELIX at Heidelberg, Munich, and Frankfurt am Main, and WALDSCHMIDT-LEITZ at Prague and Munich. Concepts and techniques established by these studies have been widely utilized for research on other typical proteins. The revolutionary advances in chemical and physical techniques after W orId War II extended the sphere of research to Tokyo in the Far East. Prof. FELIX' visit in 1955 greatly encouraged our research group in Tokyo. His death in August 1960 constituted a sad loss to protein chemistry and stimulated our group to assume responsibility for carrying on the studies. In the following decade we in Tokyo have been able to add a new development to the results on the chemical structure of protamines accumulated by the Eurqpean researchers over a period of about fifty years.

The alkaloids were of great importance to mankind for centuries, long before they were recognized . as a chemical class. The influence they have had on literature is hinted at by some of the quotations I have used as chapter headings. Their influence on folklore and on medicine has been even greater. The scientific study of alkaloids may be said to have begun with the isolation of morphine by Sertiirner in 1804. Since that time they have remained of great interest to chemists, and now in any month there appear dozens of publications dealing with the isolation of new alkaloids or the determination of the structures of previously known ones. The area of alkaloid biochemistry, in comparison, has received little attention and today is much less developed. There is a certain amount of personal arbitrariness in defining "bio­ chemistry", as there is in defining "alkaloid", and this arbitrariness is doubtless compounded by the combination. Nevertheless, it seems to me that in any consideration of the biochemistry of a group of compounds three aspects are always worthy of attention-pathways of biosynthesis, function or activity, and pathways of degradation. For the alkaloids, treatment of these three aspects is necessarily lopsided. Much has been learned about routes of biosynthesis, but information on the other aspects is very scanty. It would be possible to enter into some speculation regarding the biosynthesis of all the more than 4,000 known alkaloids.

This book is based on practical experience and is therefore written as a prac­ tical manual. The fore-runners of the book were the manuals of the first and second EMBO-Courses on "Micromethods in Molecular Biology" which were held in G6ttingen in the spring of 1970 and the autumn of 1971. This book may serve as a manual not only for the participants of the third EMBO-Course to be held in G6ttingen in autumn 1973, but also for all experimenters who are interested in using micromethods. It must be emphasized from the outset that this book is conceived as a "cook book" and not as a monograph which attempts to revue the literature on micromethods critically. The methods described here in detail are performed routinely in the authors' laboratories and include all the practical details necessary for the successful appli­ cation of the micromethods. There are many other sensitive and excellent micro­ methods which are not included in this book, because the authors feel that in a "cook book" only methods for which they have personal experience and profi­ ciency should be described. Some readers may feel that the title promises more than the present contents of this book; however, if sufficient interest is shown in this volume, it may be possible to remedy such deficiencies in future editions.

This book had its origins in some conversations held several years ago. It was felt that a monograph on the subject of tissue specificity might have some merit and interest for a number of scientific workers in the relevant disciplines. Writing was begun slowly, with interruptions; more recently, there has been much more activity, and the relevant literature has been searched and cited up to early 1973. This book was never intended as an exhaustive coverage of all possible topics related to tissue specificity. The tissues and organs covered in six chapters constitute a selected group, representative of areas in which the author has worked and which are thus directly familiar to him, plus several other areas where illustrative and important discoveries have been made. There are other areas of equal importance and interest, but the book would have been much too large if I had tried to cover all of them. The author had several groups of readers in mind, including students of immunology and the related fields of immunochemistry, biochemistry, and immunopathology. Students of general biology could find it useful. For students of medicine and practicing physicians it may provide a useful review in a field that has many clinical correlations in human disease. The author assumes that the reader has a basic knowledge of immunological concepts and technics, but for some purposes elementary treatments are cited for background reference.

Approximately one third of the mass of a mammalian red blood cell is hemo­ globin. Its major function is to bind oxygen at the partial pressure prevailing in the lungs and to release it to the tissues where the partial pressure is lower. The process whereby hemoglobin performs this essential physiological role is characterized by a cooperative interaction among its constituent subunits. A great deal of research effort has been devoted to this interaction, going back at least as far as the fitst decade of this century. Moreover, cooperativity in hemo­ globin is probably not unique; it may well be one instance of a general class of interactions that occur in biological molecules. Certain enzymes with a variety of regulatory and catalytic functions, for example, contain several sites which interact in a highly specific manner such that the affinity of a given site for the substrate is markedly influenced by the state of binding at the other sites. But whereas we know very little of the structure of most enzymes of this type, hemo­ globin is one of a very small number of biological molecules whose immensely intricate machinery has been revealed to us. We owe this insight to the group under the leadership of M. F. PERUTZ in Cambridge, England, whose research over a period of several decades culminated in a detailed description of the three­ dimensional structure.

This book presents a distillation of many years of investigation by the author and his associates on the problem of sensory reception. Both our own data and data from the scientific literature on the electron microscopy, cytochemistry, biochemistry and electrophysiology of the organs of vision, taste, smell, hearing and gravitation, are presented to show that the evolution of the sense organs of all animals on our planet is based on a receptor cell equipped with a motile antenna, a biological recorder of information concerning certain types of energy reaching the animal from the environment. The conversion or encoding of this energy into information is effected with the aid of special protein molecules positioned in the plasma membrane of the antennae. The action of the unit of energy of a stimulus on such a specific protein molecule causes a change of shape, and this is the basis of the trigger mechanism of reception, leading to the stimulation of the receptor cell and the transmission of the information encoded in this cell in the form of nerve impulses to the central nervous system. The present monograph summarizes over 30 years of working experience by the author and his associates in the field of evolution of sense organs. Material is used here from his earlier monographs: The Retina of the Eye Vertebrates, 1947, The Morphology of the Organ of Smell, 1957, The Organ of Corti: Its Histophy­ siology and Histochemistry, 1964, written jointly with L. K.

During the last decade physical and chemical methods have improved rapidly - a fact which allowed the mode of action of antibiotics to be studied - and many biochemically-oriented scientists have devoted their research to the following questions: 1. What is the metabolic pathway that is inhibited selectively, and what are the target molecules within a sensitive cell? 2. What are the relationships between the chemical structure of an antibiotic and the physicochemical properties of the sensitive mole­ cule(s)? 3. Why and how far is the action selective? 4. Is it possible to correlate the interaction with the target mole­ cule(s) with the particular biological activities observed? This monograph deals with those antibiotics which interfere with the biosynthesis of nucleic acids. The idea was to provide an insight into how to investigate the preceding questions experimentally and to solve as yet unresolved problems rather than to give a review of the current state of knowledge. Although the biochemistry of nucleic acid synthesis is known in general, the precise molecular mechanisms by which deoxyribonucleic acid is replicated or transcribed has still to be clarified. For this reason it is not yet possible to describe the molecular mechanisms by which the inhibitors of nucleic acid and protein synthesis exhibit their effects. The fact that the inhibitors of nucleic acid and protein synthesis themselves served as useful tools to obtain an insight into the mechanisms of replication, transcription and translation was one of the most exciting discoveries in this field.

The purpose of this monograph is to bring together under one cover results of research on phenomena drawn from the fields of chemistry, biochemistry, bio­ physics, virology,and cell biology. The processes and reactions considered have one important feature in common: they are endothermic and, therefore, entropy­ driven. They are, in the main, reversible reactions leading to the formation of large structures, some of which play critical roles in life processes. If one thinks only of the subunits and of the structures they form upon poly­ merization, it seems to be a contradiction that such reactions can be driven by an increase in entropy; entropy is a measure of disorder. The increase in entropy must come from some other source, usually from the release of something coincidental to polymerization. That something has been shown to be water for the case of the polymerization of tobacco mosaic virus protein. Because of the remarkable similarity of the other processes to this one, it is a permissable inference that the release of water is the source of the entropy increase and therefore the driving force for all of them. The reactions and processes brought together in this book are still the sub­ jects of active research. ;~ny of the detailed interpretations presented here must be regarded as tentative, subject to modification as new information becomes available. However, the main characteristic of each reaction or pro­ cess, its endothermic or entropy-driven nature, is well established in all but one or two instances.

This book deals primarily with the principal extracellular macromole­ cules of animal connective tissues. It attempts to answer some general questions about the biological organization of the tissues: What is the nature of this organization at various dimensional levels? What functions does the organization serve? How has it evolved? I have given major emphasis to the structures and properties of the macromolecular components of extracellular matrices from a wide range of invertebrates and vertebrates. In doing so, however, I have treated cursorily many important aspects of connective tissue biology that appeared to be only indirectly relevant to the principal questions asked. On the other hand, I have not hesitated to search for broad biological principles outside the prevailing conceptual boundaries of animal connective tissues and the lower molecular dimensional levels. The numerous speculations presented will, I hope, stimulate the reader to further thought and investigation. Acknowledgements My previously unpublished data that have been included in this volume could not have been obtained without the generous gifts of specimens and other assistance by a number of individuals and institutions. These are Dr. G. BERENSON of Louisiana State University, Drs. W. P. BRAKER and D. ZUMWALD of the Shedd Aquarium, Dr. S. H. CHUANG of the Univer­ sity of Singapore, Dr. L. G. CLARK and Mr. U. M. VARELA-DIAZ of the University of Pennsylvania, the Government of Nicaragua, Dr. E. CLARK of Cape Haze Marine Laboratories, Mr. C. E.

Our knowledge of the biochemistry and biophysics of dinitrogen fixa­ tion has developed rapidly in the 15 years since the first N2-fixing enzyme system was successfully extracted from a bacterium. This peri­ od has produced a literature that now describes the N2 fixation reac­ tion and the nitrogenase enzyme itself in sophisticated terms, though a detailed reaction mechanism at the chemical level has not yet emerged. It is the purpose of the present monograph to present an in-depth re­ view, analysis, and integration of this research as is possible with a non-contributed publication and to relate this work to considera­ tions of N2 fixation that reach beyond the confines of the biochem­ ist's laboratory. The first section is directed as much toward the general science read­ er as toward the specialist. It covers the agricultural origins of man's interest in N2 fixation and also pertinent areas of taxonomy, physiology, and evolution. Ecological aspects of the subject include a comprehensive evaluation of the nitrogen cycle leading to a sub­ stantially greater estimate of the rate of global N2 fixation than previous ones. The treatment is of a survey fashion, in part to pro­ vide a general over-view of N2 fixation and in part to provide context for the biochemistry and biophysics that follow in the second section.

In the few years since the first edition of this book made its appearance, under­ takings in the area of protein sequence determination have increased at an almost logarithmic pace. The logic governing such efforts has, predictably, retreated from a simple sense of curiosity in achieving something that had not previously been done, to be replaced by an absolute requirement for sequence information as the best means for understanding heretofore unattainable aspects of chemical, and structural and functional mechanistic phenomena. Witness, for example, recent volumes of the Annual Review of Biochemistry and other review journals, which treat the genetic control of mitochondrial proteins, mechanisms of enzyme action, the immunochemistry of collagen, and the role of lysosomal enzymes in the lipid storage diseases - all on the basis of known protein sequence information. One must note, too, the appearance of related works in the area of nucleic acid sequencing. The technologic advances in chemical sequencing procedures have proliferated at a remarkable rate. It is in the area of instrumentation, however, that the greatest advances have taken place. As a consequence of this, each chapter (with one single exception) in this book has been extensively revised and updated. Entire chapters have been replaced in several cases, without minimizing the value of their original content. In addition, a second volume will appear soon, dealing with subjects not covered in the present book.

Enzyme kinetics has undergone very rapid growth and development during the past fifteen years and has been well received by the biochemical community. A cursory glance at the current biochem­ ical literature reveals the increasing popularity of enzyme ki­ netics1 yet, there are very few books available to guide the enzymologist who wishes to conduct kinetic experiments. This monograph was undertaken to provide the fledgling kineticist with an outline of contemporary initial rate enzyme kinetics. A large portion of the material contained in this book is presented in a second-year, graduate-level course in biochemistry at Iowa State University. I have found that the presentation in this course has enabled students without a strong background in math­ ematics to undertake initial rate studies at the research bench. The monograph obviously is more comprehensive than any course could be, and should permit similar accomplishment. As the title implies, the major emphasis of this monograph is on initial rate enzyme kinetics. I considered at length the advis­ ability of including chapters on integrated rate equations and on the theory and application of rapid reaction kinetics, such as rapid-mixing stopped-flow, and temperature-jump kinetics. These, however, are topics that would require a good deal of space to develop if they were to be helpful to the beginner.

1. Secondary Metabolism and Differentiation In addition to the primary metabolic reactions, which are similar in all living beings (formation and breakdown of nucleic acids and proteins as well as of their precursors, of most carbohy­ drates, of some carboxylic acids, etc. ), a vast number of metab­ olic pathways lead to the formation of compounds peculiar to a few species or even to a single chemical race only. These reac­ tions, in accord with CZAPEK (1921) and PAECH (1950), are summed up under the term "secondary metabolism", and their products are called "secondary metabolites. " The wide variety of secondary products formed in nature includes such well-known groups as alkaloids, antibiotics, cardiac glyco­ sides, tannins, saponins, volatile oils, and others. A consider­ able number of them are of economic importance in therapeutics or technology. Although secondary products are produced by micro­ organisms, higher plants, and animals (cf. LUCKNER, 1972), most of the substances are found in the plant kingdom. The lack of mechanisms for true excretion in higher plants may result in this unequal distribution, the "waste products" of metabolism in plants instead being accumulated in the vacuoles, the cell walls, or in special excretory cells or spaces of the organism ("metabolic excretion," cf. FREY-WYSSLING, 1935, 1970; MOTHES, 1966a, b, 1972; LUCKNER et al. , 1976. Many secondary substances have, however, a direct biologic func­ tion. They can be regulatory effectors, e. g.

The development of an area of scientific research is a dynamic process with its own kinetic equations and its own physical mech­ anism. The study of fast chemical interactions and transformations is such an area, and while it is tempting to draw analogies or to speculate about the simplest model system, the lack of ade­ quately averaged observables is an annoying obstacle to such an undertaking. Sciences suffering from such conditions usually avoid quantitative models, be they primitive or complex. Instead, they prove their point by "case histories". Chemical relaxation kinetics started as an offspring of research in acoustics. In some aqueous ionic solutions anomalous acoustic absorption had been observed. A systematic study traced the cause of this absorption, showing that the covered frequency range and the intensity of the absorption were related in a predictable manner to the rate at which ions can interact and form structures differing in volume from the non interacting species. The step from this experimental observation and its correct, non­ trivial explanation to the discovery that all fast chemical pro­ cesses must reveal themselves quantitatively in the relaxation rate of a perturbed equilibrium state, and that perturbation para­ meters other than sound waves can be used for its exploitation, was made by MANFRED EIGEN in 1954. The foresightedness of K.F.

Transition metal ions in biological systems are of interest in biology, biochemistry, chemistry, medicine, and physics. Scien­ tists with rather different viewpoints, employing many methods, have contributed to this area. A concise review of the current state of the field will, to some extent, reflect the special knowledge of the person writing it - in this case application of physical methods to the investigation of metal coordination. x­ ray diffraction is one of the most important of these methods, but a useful treatment of X-ray structure analysis would be com­ parable in size with and beyond the scope of the monograph. Many results of X-ray diffraction studies are, of course, presented. Electron paramagnetic resonance spectroscopy has played a major part in the rapid advance in knowledge of the electronic struc­ tures of transition metal ions in biological systems. More gener­ ally, measurements involving light, microwaves, and magnetic fields are capable of producing much new information, and the required instrumentation is available at most research institu­ tions. Therefore light absorption and paramagnetic resonance are treated in depth. The principles described in the latter discus­ sions are broadly applicable, for example to the promising tech­ niques of X-ray spectroscopy (utilizing synchrotron radiation) and lanthanide-perturbed, very high-resolution nuclear magnetic resonance spectroscopy.

Confusion now hath made his masterpiece Macbeth II iii 72 Whence and what are those execrable shape? Paradise Lost Ib 1 681 Confusion worse confounded Paradise Lost Ib 1 995 When the manuscript for the first part of this book was proposed, it was anticipated that the discussion of the entire field of protein se­ quencing could be covered in a single volume - from purification and characterization of the protein through fragmentation by chemical or enzymic means and, finally, to reassembly of the identified individual peptides into the reconstructed total sequence. It soon became evident that this would not be possible. While the intent was to restrict the expose of procedures only to that information concerned with "hands on" wet chemistry, it became apparent that a thorough presentation would require, in addition, a discussion of certain instrumental and more theoretical approaches not included in the first volume. Furthermore, the entire understanding of the field of protein sequencing has advanced appreciably since the inception of this book. The purpose of the first volume was to provide practical information in sufficient detail to permit the researcher to undertake the actual sequencing procedures in his own laboratory.

This publication presents the culmination of collaborative effort between specialists in the wide range of disciplines concerned with the effects of ionizing radiations on nucleic acids. The authors belong to a group formed under the aegis of the Com­ mission of the European Communities some eight years ago with the object of facilitating the exchange of ideas and inforrration between European scientists working in this field. The Commission'S aim was not to replace traditional information channels, but to strengthen the various links between the scien­ tists in the group, as if they were working together in a single team. In addition to the annual meetings of the group, contact was maintained by individual visits, exchanges of young scientists, experiments using mutual equipment, and the regular publication of a Newsletter, mainly to announce the availability of preprints. Bruxelles, December 1977 A. J. Bertinchamps Commission of the European Communities. Preface Mankind today is faced with a choice of cardinal importance, namely, deciding on the source and quantity of energy to be made available for tomorrow's world. If, as is probable, the energy is to be mainly of nuclear origin, we must expect a marked ex­ pansion of the nuclear industry, which could well become the world's leading industry in the not-too-distant future. This would carry with it the problems caused by the presence of enor­ mous quantities of radioactivity, despite the stringent precau­ tions taken to date and those to be taken in future.

The aim of this monograph is to summarize the essential features which characterize the behavior of regulatory systems. Firstly we discuss the laws which govern ligand binding in thermodynamic terms. The basic cooperative and allosteric phenomena are des­ cribed in thermodynamic terms without assuming any particular mo­ del. Then the molecular models developed by Monod, Wyman and Changeux and by Koshland, Nemethy and Filmer are presented in detail. Special emphasis has been given to the analysis of the Hill coefficient and its meaning both in thermodynamic terms and in terms of the two allosteric models: the concerted model of Monod, Wyman and Changeux and the sequential model of Koshland, Nemethy and Filmer. Special types of cooperativities are dis­ cussed in some detail namely, cooperativity stemming from ligand­ coupled protein association or dissociation, negative cooperati­ vity and half-of-the-sites reactivity. A slightly extended space was devoted to the discussion of negative cooperativity and half­ of-the-sites reactivity, since the existence of these phenomena and their possible biological importance is less of a common knowledge than positive cooperativity. This monograph does not attempt to be a review of specific examples analyzed according to one model or another. Rather, an attempt is made to provide the reader with the quantitative tools to analyze any specific regulatory system. Last but not least, I would like to thank Prof. F. W. Dahlquist from the Institute of Molecular Biology, the University of Oregon (Eugene) and Prof. D. E. Koshland, Jr.

Studies of chemical recognition in biology were initiated about half a century ago with the flrst kinetic data obtained on enzyme catalysis and inhibition. They led to a rather static representation of the recognition process illustrated by the lock and key model that still continues to influence our overall image of recognition and its specificity. In several cases, crystallographic studies of enzyme-substrate complexes have supported this model. Indeed, in a crystallized ligand-enzyme complex, a close fltting is observed between the active center of the enzyme and the functional groups of the ligand. How­ ever, this does not necessarily result from a direct recognition process between rigid structures, but may result from a progressive adaptation during which the initial struc­ tures of the enzyme and the ligand are modified (induced-flt mechanism). Recently, a great deal of work has been devoted to the study of recognition in more complex systems such as the replication or the translation machin~ries; clearly, the extraordinary precision of such systems cannot be explained solely in terms of physical matching between enzymes and their substrates. This has led to a noticeable change of perspective in these areas. As a result of the new kinetic viewpoint, one rather focuses on the time-course of the processes, on the kinetic balance between steps of the reaction, on the energy-accuracy relationships and on the strategies which permit the achievement of high precision using relatively error-prone components in an appropriate dynamic interplay.

The last 10 years have seen an enormous growth in our understanding of the molecular organisation of biological membranes. Experimental methods have been devised to meas­ ure the translational and rotational mobility of lipids and proteins, thereby furnishing a quantitative basis for the concept of membrane fluidity. Likewise, the asymmetry of bi­ layer membranes as evidenced by the asymmetric insertion of proteins and lipids has been put on firm experimental ground. At higher molecular resolution it has been possible to provide a detailed pi2ture of the molecular conformation and dynamics of lipids and, to some extent, even of small peptides embedded in a bilayer matrix. Many of these achieve­ ments would not have been possible without the application of modem spectroscopic methods. Since these techniques are scattered in a variety of specialized textbooks the present monograph attempts to describe the key spectroscopic methods employed in present-day membrane research at an intermediate level. There is no question that the elusive detailed structure of the biological membrane demands a multiplicity of experi­ mental approaches and that no single spectroscopic method can cover the full range of physical phenomena encountered in a membrane. Much confusion in the literature has arisen by undue generalizations without considering the frequency range or other limi­ tations of the methods employed. It is to be hoped that the present monograph with its comprehensive description of most modem spectroscopic techniques, will contribute to- .

The material of this volume was originally planned to be incorporated in the preceding monograph Mechanics and Energetics of Biological Transport. A separate and coherent treatment ofthe variety of bioelectrical phenomena was considered preferable, mainly for didactic reasons. Usually, the biologist has to gather the principles of bioelectricity he needs from different sources and on different levels. The present book intends to provide these principles in a more uniform context and in a form adjusted to the problems of a biol­ ogist, rather than of a physicist or electrical engineer. The main emphasis is put on the molecular aspect by relating the bioelectrical phenomena, such as the membrane diffusion potentials, pump potentials, or redox potentials, to the properties of the membrane concerned, and, as far as pOSSible, to specific steps of transport and metabolism of ions and nonelectrolytes. Little space is devoted to the familiar and widely used representation of bioelectrical phe­ nomena in terms of electrical networks, of equivalent circuits with batteries, resistances, capacities etc. In order to elucidate the basic principles, the formal treatment is kept as simple as pOSSible, using highly Simplified models, based on biological systems. The corresponding equations are derived in two ways: kinetically, i. e. in terms of the Law of Mass Action, as well as energetically, i. e. , in terms of Nonequilibrium Thermodynamics.

stimulating introduction to a school of thinking and a body of research that is not widely known or easily accessible to us. His attempt to provide a unify­ ing theory of sensory receptor mechanisms based on evolutionary principles is unique and imaginative. Among the joys of a career in science is the opportunity to rub shoulders with people of outstanding intellectual power and, with luck, to have the privilege of their friendship. In May of 1979 I visited the U.S.S.R. as a guest lecturer in chemical senses. During the 8 days that I spent in the beautiful city of Leningrad I had the great good fortune to become acquainted with Yakov Abramovich Vinnikov, and we quickly became good friends. A dinner party at his apartment is among the warmest of my memories, and nothing could please me more than to have the opportunity to introduce him in per­ son to my colleagues in Western Europe, the Americas, Japan, and Australia. That, I am sorry to say, is a most unlikely eventuality. For the time being, introducing his fertile mind through this book is the best I can do.