Microbial Membrane Transport Systems

Transport of molecules across the cell membrane is a fundamental process of all living organisms. It is essential for understanding growth, development, nutrition as well as uptake and excretion of exogenous or synthesized molecules. Microbes respresent general and basic functional systems where many transport processes have been studied on a molecular basis. Knowledge of the microbial transport processes will provide new perspectives to treatments by inhibitors, drugs, antibiotics, vitamins, growth promotion compounds, activators and toxic compunds of various kinds.

With the growing realization that microbial transport proteins exhibit homologies to various degrees not only among themselves, but also to membrane proteins of eukaryotic cells, this book represents a timely review of the current state of knowledge and research.

Transport of molecules across the cell membrane is a fundamental process of all living organisms. It is essential for understanding growth, development, nutrition as well as uptake and excretion of exogenous or synthesized molecules. Microbes respresent general and basic functional systems where many transport processes have been studied on a molecular basis. Knowledge of the microbial transport processes will provide new perspectives to treatments by inhibitors, drugs, antibiotics, vitamins, growth promotion compounds, activators and toxic compunds of various kinds.

The development of recombinant DNA techniques has yielded a large amount of data about the molecular mechanisms of solute translocation across microbial membranes. Kinetic and chemical analysis has also defined many of the properties of the transport proteins involved. It is becoming clear that the transport proteins show many homologies between themselves and with membrane proteins of eucaryotic cells. This book, based on a conference at the royal Society, brings together contributions from many leading workers in the field, presenting common themes and information that have emerged.

Much of the information currently available on the transport systems of bacterial and animal cell membranes and their mode of coupling to metabolic supply of energy can be found in this volume. Consideration of the participating enzymes dictated the choice of topics: Several transport systems where little information is available on the enzymology of the process are not included, while separate chapters deal with y-glutamyl transpeptidase and intestinal disaccharidases which meet many of the requirements of transport enzymes. The volume also includes two chapters on photosynthetic membranes as a general introduction to the topic. Other aspects of biological transport and photosynthesis will be developed in detail in a forthcoming volume now in preparation. These chapters reveal the excitement and rapid advance of the field, the daily reports of new concepts, new techniques, and new experimental findings which instantly interact to generate further progress. Our aim was to provide a starting point for those who are just beginning, and an opportunity for others to stop, take stock, and start in a new direction. My warmest thanks to all who contributed to this volume.

The development of recombinant DNA techniques has yielded a large amount of data about the molecular mechanisms of solute translocation across microbial membranes. Kinetic and chemical analysis has also defined many of the properties of the transport proteins involved. It is becoming clear that the transport proteins show many homologies between themselves and with membrane proteins of eucaryotic cells. This book, based on a conference at the royal Society, brings together contributions from many leading workers in the field, presenting common themes and information that have emerged.

In recent years it has become evident that transport processes across membranes play a crucial role in many metabolic systems. The activities of these transport processes often determine the physiology of the organisms. This book presents a state of the art review on the analysis of a wide variety of transport systems from bacteria and eukaryotic cells. A selection has been made of those systems that have been studied at the molecular level with special emphasis paid to the energetic and other biophysical properties. The different classes of transport systems are presented in the following: primary transport, secondary transport, phosphotransferase systems, channels and porines and macromolecular transport. Within each class of transporters several systems are presented by the leading experts in the field, which has resulted in a very broad overview of transport processes in biological cells. In this way the differences in the mechanisms used for translocation become evident while on the other hand features common to the different transport systems are revealed.