Proteases Structure And Function

Proteolysis is an irreversible posttranslational modification affecting each and every protein from its biosynthesis to its degradation. Limited proteolysis regulates targeting and activity throughout the lifetime of proteins. Balancing proteolysis is therefore crucial for physiological homeostasis. Control mechanisms include proteolytic maturation of zymogens resulting in active proteases and the shut down of proteolysis by counteracting endogenous protease inhibitors. Beyond the protein level, proteolytic enzymes are involved in key decisions during development that determine life and death – from single cells to adult individuals. In particular, we are becoming aware of the subtle role that proteases play in signaling events within proteolysis networks, in which the enzymes act synergistically and form alliances in a web-like fashion. Proteases come in different flavors. At least five families of mechanistically distinct enzymes and even more inhibitor families are known to date, many family members are still to be studied in detail. We have learned a lot about the diversity of the about 600 proteases in the human genome and begin to understand their physiological roles in the degradome. However, there are still many open questions regarding their actions in pathophysiology. It is in this area where the development of small molecule inhibitors as therapeutic agents is extremely promising. Approaching proteolysis as the most important, irreversible post-translational protein modification essentially requires an integrated effort of complementary research disciplines. In fact, proteolytic enzymes seem as diverse as the scientists working with these intriguing proteins. This book reflects the efforts of many in this exciting field of research where team and network formations are essential to move ahead.

In the past ten years, a number of proceedings of symposia on the structure and function of proteolytic enzymes have been pub lished. Their coverage of acid proteases has been limited, mainly due to the lack of significant new information on the structure of these enzymes. In the last four years, however, the primary and tertiary structures of a number of acid proteases have been deter mined, prompting the need to discuss the meanings of the old data and the possibilities for new experimentations. It was for this purpose that the "Conference on Acid Proteases: Structure, Function, and Biology" was organized. It took place at the University of Oklahoma on November 21-24, 1976. This book is a collection of the main lectures delivered at the Conference. Acid Proteases, by definition refers to a group of proteases having an optimal pH in acidic solutions. The classic examples are pepsin and chymosin. Some catalytic features are obviously shared by these proteases, most notably, their inhibition by pepstatin. The use of active center-directed inactivators such as diazoacetyl norleucine methyl ester and 1,2-epoxy-3-(p-nitrophenoxy)propane has shown that two catalytic aspartyl residues are present in most of these enzymes. These apparent cornmon features have prompted the suggestion by several investigators to name this group of enzymes "aspartyl proteases" or "carboxyl proteases".

Structure–Function Relationships of Proteolytic Enzymes provides information pertinent to the fundamental aspects of proteolytic enzymes. This book presents the historical role of proteolytic enzyme as a group in protein and enzyme chemistry. Organized into 23 chapters, this book begins with an overview of the results obtained from investigation on the chymotrypsinogens of porcine origin. This text then examines the differences of amino acid sequence between chymotrypsin, trypsin, and elastase that affect the substrate binding site, which reflect the specificity differences between these enzymes. Other chapters consider the kinetic parameters related to the trypsin-catalyzed hydrolysis of several model peptides. This book discusses as well the acetylation of trypsin, which result in functional consequences varying from complete inactivation to promotion of activity. The final chapter deals with the physical properties of stem bromelain in comparison with the data for three other sulfhydryl proteases of plant origin. This book is a valuable resource for enzymologists, microbiologists, and biochemists.

Handbook of Proteolytic Enzymes, Second Edition, Volume 1: Aspartic and Metallo Peptidases is a compilation of numerous progressive research studies on proteolytic enzymes. This edition is organized into two main sections encompassing 328 chapters. This handbook is organized around a system for the classification of peptidases, which is a hierarchical one built on the concepts of catalytic type, clan, family and peptidase. The concept of catalytic type of a peptidase depends upon the chemical nature of the groups responsible for catalysis. The recognized catalytic types are aspartic, cysteine, metallo, serine, threonine, and the unclassified enzymes, while clans and families are groups of homologous peptidases. Homology at the level of a family of peptidases is shown by statistically significant relationship in amino acid sequence to a representative member called the type example, or to another member of the family that has already been shown to be related to the type example. Each chapter discusses the history, activity, specificity, structural chemistry, preparation, and biological aspects of the enzyme. This book will prove useful to enzyme chemists and researchers.

Viral Proteases and Their Inhibitors provides a thorough examination of viral proteases from their molecular components, to therapeutic applications. As information on three dimensional structures and biological functions of these viral proteases become known, unexpected protein folds and unique mechanisms of proteolysis are realized. This book investigates how this facilitates the design and development of potent antiviral agents used against life-threatening viruses. Users will find descriptions of each virus that detail the structure and function of viral proteases, discuss the design and development of inhibitors, and analyze the structure-activity relationships of inhibitors. This book is ideal biochemists, virologists and those working on antiviral agents. Provides comprehensive, state-of-the-art coverage of virus infections, the virus lifecycle, and mechanisms of protease inhibition Analyzes structure-activity relationships of inhibitors of each viral protease Presents an in-depth view of the structure and function of viral proteases

In view of rapidly growing research in the deregulation of proteases and their impact in human health and diseases, this book will highlight existing and emerging research in this exciting area. In-depth critical state-of-the-art reviews will be written by established investigators on proteases dysfunctions associated with pathogenesis of different diseases that are known to occur due to deregulation of proteolytic systems. Multidisciplinary approaches demonstrating biochemical and signal transduction mechanisms associated with deregulation of proteases leading to manifestation of the diseases will be discussed. The book highlights the roles of both intracellular and extracellular proteases in health and disease.

Cancer-Leading Proteases: Structures, Functions, and Inhibition presents a detailed discussion on the role of proteases as drug targets and how they have been utilized to develop anticancer drugs. Proteases possess outstanding diversity in their functions. Because of their unique properties, proteases are a major focus of attention for the pharmaceutical industry as potential drug targets or as diagnostic and prognostic biomarkers. This book covers the structure and functions of proteases and the chemical and biological rationale of drug design relating to how these proteases can be exploited to find useful chemotherapeutics to fight cancers. In addition, the book encompasses the experimental and theoretical aspects of anticancer drug design based on proteases. It is a useful resource for pharmaceutical scientists, medicinal chemists, biochemists, microbiologists, and cancer researchers working on proteases. Explains the role of proteases in the biology of cancer Discusses how proteases can be used as potential drug targets or as diagnostic and prognostic biomarkers Covers a wide range of cancers and provides detailed discussions on protease examples

Methods included in this volume apply to the expression and characterization of retroviral proteases and their inhibitor/substrate design.