This collection of 11 chapters is devoted to a survey of artificial and reconsti tuted membrane systems. These are fundamental themes and areas of great current importance in membrane biochemistry. They also relate well to the founding concept of this series, namely, to present studies that progressively work toward and provide us with an "integrated view of the cell. " In this volume, it is the application of a wide range of physiochemical and biochemi cal techniques to the study of membrane lipids and proteins which serves to demonstrate the significant progress that has been made in this field over the past 25 years. From the understanding of simplified artificial systems, it is hoped that it will ultimately be possible to gain a more accurate understanding of natural biological membranes, in all their diversity. This book is an appropriate successor to Volume 13 of the series, which deals with fluorescence studies on biological membranes. Indeed, the present chapter by Lesley Davenport and colleagues was originally due for inclusion in Volume 13, but has been held over for inclusion in this volume, where it integrates remarkably well with the other topics. The extremely varied and interesting contents of this volume are now briefly outlined. In Chapter I, Jacqueline A. Reynolds and Darrell R. McCaslin pres ent a pertinent survey of the interaction of detergents with membrane lipids and proteins, together with an assessment of the reconstitution process.

We are extremely pleased that all of the chapters in this volume provide up-to-date information on a variety of topics of interest to scientists working on membrane biology. As in the past, we have attempted to expedite the transition from submission of the manuscripts to publication in order to make the reviews as timely as possible. Cell biology and molecular biology are increasingly be coming concerned with the study of structural elements in cells and their assem bly. The rules which govern membrane synthesis, assembly and interaction of membrane components with other cellular elements, notably the cytoskeleton, are at the center of research in these fields. We will continue in subsequent volumes of this series to focus on these areas. We would welcome suggestions of topics which would benefit from a review at the present time. We thank all of the contributors for providing these very excellent reviews and for doing so in a timely fashion. Elliot L. Elson William A. Frazier Luis Glaser St. Louis, Missouri vii CONTENTS Chapter 1 Chemotactic Transduction in the Cellular Slime Molds William A. Frazier, Beth L. Meyers-Hutchins, Gordon A. Jamieson, Jr. , and Nancy J. Galvin 1. Introduction-Chemotaxis in the Cellular Slime Molds . . . . . . . . . . . 2. Receptors for Chemoattractants of the Cellular Slime Molds . . . . . . . 4 2. 1. The Folate Receptor of Vegetative D. discoideum . . . . . . . . . . . 4 2. 2. The cAMP Receptor of Aggregating D. discoideum . . . . . . . . . 6 3. Putative Transduction Events in D. discoideum . . . . . . . . . . . . . . . . . 10 3. 1. cGMP and Guanylate Cyclase . . . . . . . . . . . . . . . . . . . . . . . . . . .

Current Topics in Bioenergetics, Volume 9 presents the theoretical, thermodynamic perspective of energy transducing reactions. This book provides a detailed kinetic analysis of a specific aspect of an ion pump. Organized into seven chapters, this volume begins with an overview of the quantitative relations between measurable parameters of energy-transducing systems. This text then examines the probes for intracellular pH determination, which stimulate the development of additional methods and their application in pathology and pharmacology. Other chapters consider studies with isolated proteins or protein complexes derived from the membranes. This book discusses as well the chemistry of photosynthesis and oxidative phosphorylation. The final chapter deals with the advances in the use of photo affinity labeling in the study of the structure of ligand sites on proteins, which became possible only in conjunction with the development of methods for the isolation of peptides and their sequence determination. This book is a valuable resource for biologists and biochemists.

A preface should justify the existence of the book it precedes and this is invariably done in scientific texts by reference to the explosive growth of the field since the last such volume appeared. In molecular biology, most fields can be justifiably described as growing explosively, as should be the case for a young and vigorous science, but the study of membrane proteins stands out as one which has taken giant strides in the last few years. Ignorance of the structure and function of membrane proteins at the molecular level was certainly not due to lack of interest but rather was a result of lack of appropriate techniques. It has above all been the development of new experimental methods which has wrenched membrane biochemistry out of what Anthony Martonosi fetchingly called its 'romantic phase' (Le. lots of ideas and few facts), into an era when the determination of membrane protein structure and mechanism is a reasonable goal. Membrane proteins are generally classified as peripheral or integral. Peripheral proteins are relatively easily dissociated from membranes by mild treatments whence their study is essentially no different to that of soluble proteins. This book therefore concentrates on integral proteins which are strongly bound to the membrane by hydrophobic interactions with lipids. A crucial step in their study is of necessity the d~velopment of methods of solubilization and purification under non-denaturing conditions.