Protein-protein interactions (PPI) are at the heart of the majority of cellular processes, and are frequently dysregulated or usurped in disease. Given this central role, the inhibition of PPIs has been of significant interest as a means of treating a wide variety of diseases. However, there are inherent challenges in developing molecules capable of disrupting the relatively featureless and large interfacial areas involved. Despite this, there have been a number of successes in this field in recent years using both traditional drug discovery approaches and innovative, interdisciplinary strategies using novel chemical scaffolds. This book comprehensively covers the various aspects of PPI inhibition, encompassing small molecules, peptidomimetics, cyclic peptides, stapled peptides and macrocycles. Illustrated throughout with successful case studies, this book provides a holistic, cutting-edge view of the subject area and is ideal for chemical biologists and medicinal chemists interested in developing PPI inhibitors.

Advances in Botanical Research publishes in-depth and up-to-date reviews on a wide range of topics in plant sciences. Currently in its 76th volume, the series features several reviews by recognized experts on all aspects of plant genetics, biochemistry, cell biology, molecular biology, physiology and ecology. - Publishes in-depth and up-to-date reviews on a wide range of topics in plant sciences - Contains commentary by recognized experts on all aspects of plant genetics, biochemistry, cell biology, molecular biology, physiology, and ecology - This volume features reviews of the fast moving field of plant cyclotides

Cyclic peptides are increasingly employed as chemical tools in biology and drug discovery. They have gained a lot of interest as alternative sources of new drugs to traditional small molecules. This book introduces cyclic peptides and provides a thorough overview of biosynthetic and fully synthetic approaches to their preparation. Following an introduction to cyclic peptides, biosynthetic and traditional chemical routes to cyclic peptides are reviewed. Due to their size, their synthesis is not trivial. Recent advances in the incorporation of novel structural units are presented in addition to how synthesis and biological methods can be combined. The chemical analysis of this molecular class is also discussed. Furthermore, chapters detail the progression of cyclic peptides as tools in biology and as potential drugs, providing a future vision of their importance. In total, this book provides the reader with a comprehensive view of the state-of-the-art of cyclic peptides, from construction to possible clinical utility. This book will be an essential resource for students, researchers and scientists within industry in medicinal, bioorganic, natural product and analytical chemistry fields.

Lasso peptides form a growing family of fascinating ribosomally-synthesized and post-translationally modified peptides produced by bacteria. They contain 15 to 24 residues and share a unique interlocked topology that involves an N-terminal 7 to 9-residue macrolactam ring where the C-terminal tail is threaded and irreversibly trapped. The ring results from the condensation of the N-terminal amino group with a side-chain carboxylate of a glutamate at position 8 or 9, or an aspartate at position 7, 8 or 9. The trapping of the tail involves bulky amino acids located in the tail below and above the ring and/or disulfide bridges connecting the ring and the tail. Lasso peptides are subdivided into three subtypes depending on the absence (class II) or presence of one (class III) or two (class I) disulfide bridges. The lasso topology results in highly compact structures that give to lasso peptides an extraordinary stability towards both protease degradation and denaturing conditions. Lasso peptides are generally receptor antagonists, enzyme inhibitors and/or antibacterial or antiviral (anti-HIV) agents. The lasso scaffold and the associated biological activities shown by lasso peptides on different key targets make them promising molecules with high therapeutic potential. Their application in drug design has been exemplified by the development of an integrin antagonist based on a lasso peptide scaffold. The biosynthesis machinery of lasso peptides is therefore of high biotechnological interest, especially since such highly compact and stable structures have to date revealed inaccessible by peptide synthesis. Lasso peptides are produced from a linear precursor LasA, which undergoes a maturation process involving several steps, in particular cleavage of the leader peptide and cyclization. The post-translational modifications are ensured by a dedicated enzymatic machinery, which is composed of an ATP-dependent cysteine protease (LasB) and a lactam synthetase (LasC) that form an enzymatic complex called lasso synthetase. Microcin J25, produced by Escherichia coli AY25, is the archetype of lasso peptides and the most extensively studied. To date only around forty lasso peptides have been isolated, but genome mining approaches have revealed that they are widely distributed among Proteobacteria and Actinobacteria, particularly in Streptomyces, making available a rich resource of novel lasso peptides and enzyme machineries towards lasso topologies.