From Phage Display And Venoms To Protease Resistant Peptides Design Of Bbb Shuttles And Peptides Targeting Egf

Peptides play a critical role in human physiology and harbour a huge potential as therapeutic agents. In this thesis, new peptides have been discovered as ligands for the epidermal growth factor (EGF) and as new BBB-shuttles, using phage display and chemical synthesis of peptides and proteins. EGF is overexpressed in several cancers, inducing the proliferation and survival of these cells. By inhibiting EGF, we will prevent the activation of the receptor and, consequently, its negative effects. Moreover, phage display is a powerful tool to identify peptide ligands. However, only L-peptides can be displayed, which are protease unstable. Hence, mirror image phage display was developed to identify D-peptides, more stable in front of proteases. In this methodology, the selection is carried out against the mirror image of the original target and, after the panning selection and the synthesis of the enantiomer of the ligand, D-peptides are obtained. In this regard, the enantiomer of EGF was synthesised using a combination of solid-phase peptide synthesis and native chemical ligation. After the panning of two phage display peptide libraries against the immobilised protein, nine sequences were selected and synthesised with D-amino acids. Three of these peptides have high affinities for EGF and are stable in serum proteases for more than 24h. Most potential drugs for the treatment of central nervous system disorders (such as brain cancer and Alzheimer's disease) do not cross the blood-brain barrier (BBB). Much effort has been devoted to the discovery of BBB-shuttle peptides – entities that have the capacity to carry cargoes across the BBB. The sources of BBB-shuttle peptides are diverse, ranging from the mimicry of endogenous proteins to the use of phage display. Phage display has been applied against a human BBB cellular model which consists in the co-culture of human brain capillary endothelial cells and bovine pericytes. From the screening of a phage display library containing random 12-amino acid sequences, SGVYKVAYDWQH (SGV) was selected. Validation studies were performed confirming that SGV is able to increase the uptake of a model protein in endothelial cells. When a BBB-shuttle is conjugated to a cargo, the ratio BBB-shuttle:cargo can range from 1:1 to 400:1, depending on the cargo. However, there are cases where the modification of the cargo with one copy of the BBB-shuttle is not sufficient to promote its passage through the BBB. More copies can be introduced, but a mixture of ratios of BBB-shuttle:cargo conjugates may be obtained. In those cases, it may be interesting to use multivalent BBB-shuttles, where more than one copy of the shuttle is attached to a core, which is linked to the cargo at one position. In this regard, branched dimerisation of a known BBB-shuttle was explored to enhance BBB permeability of model proteins. The results obtained with THRre peptide as the BBB-shuttle suggest that the mild improvement in permeability may not compensate the increased synthetic effort that these constructs represent. Moreover, chlorotoxin (CTX), a disulphide-rich peptide found in the venom of a scorpion, is reported to be able to enter the brain and bind specifically to tumour tissue. However, CTX is a relatively large peptide (36 amino acids) to be used as a BBB-shuttle, where we may need to scale it up or modify it. In this regard, we designed minimised versions of CTX (MiniCTXs) and evaluated their BBB properties, as well as their toxicity and stability. The results from these experiments produced two peptides as good BBB-shuttles, with similar stability, cellular uptake and BBB permeability than the best BBB-shuttles.

The availability of various in vitro and in vivo techniques has considerably advanced the research on drug transport and metabolism across the blood-brain barrier (BBB). These specialized and sophisticated experimental strategies are of fundamental importance if one is to gain a greater understanding of enhanced and selective drug delivery to the brain. The reader will find in this book methods for in vitro endothelial/astrocyte cell culture models, and for in vivo intracerebral microdialysis to study drug tranport across the BBB. This book, however, is not merely a laboratory manual consisting of recipes for BBB research; it permits the presentation of the different methods in fine detail, revealing tricks and short cuts that frequently do not appear in the literature. The researcher is well aware that differences (subtle or otherwise) in experimental steps used in different laboratories may influence the outcome of any particular procedure. The book also illustrates the accessibility and the application of the different methods in different species. Background information of the protocol is given in every chapter, which also contains a literature list that the reader may wish to refer to for further information. This volume will be invaluable to basic researchers as well as to those involved in the search for agents suitable for pharmaceutic intervention in the central nervous system.

In this book, a summary and update of the most important areas of CPP research are presented, whilst raising relevant questions for further development. The CPP sequences are presented and discussed throughout the book. The methods for testing CPP mechanisms are discussed in detail. Various approaches for the testing of endocytotic pathways of CPP uptake are also described. Different CPP uptake experiments are compared since it is becoming clear that it is often best to apply several methods in a complementary manner in order to most comprehensively evaluate CPP uptake mechanisms due to the complexity of these processes. A brief summary of functionality issues of CPPs, both in vitro and in vivo are discussed. Therapeutic potential of CPPs and commercial developments are discussed. The monograph is written for researchers and students in the field.

The Bad Bug Book 2nd Edition, released in 2012, provides current information about the major known agents that cause foodborne illness.Each chapter in this book is about a pathogen—a bacterium, virus, or parasite—or a natural toxin that can contaminate food and cause illness. The book contains scientific and technical information about the major pathogens that cause these kinds of illnesses.A separate “consumer box” in each chapter provides non-technical information, in everyday language. The boxes describe plainly what can make you sick and, more important, how to prevent it.The information provided in this handbook is abbreviated and general in nature, and is intended for practical use. It is not intended to be a comprehensive scientific or clinical reference.The Bad Bug Book is published by the Center for Food Safety and Applied Nutrition (CFSAN) of the Food and Drug Administration (FDA), U.S. Department of Health and Human Services.

Divided into three parts this volume summarizes the most important areas of Cell-Penetrating Peptides (CPP) research . Part one briefly presents the historical background of CPP studies and the classifications of the available CPPs, and then summarizes the approaches for prediction of novel CPPs. Part two mainly describes the methods for studies of “naked” CPPs, that is, CPPs without conjugated cargos. Last but not least part three presents a representative and brief summary of functionality issues of CPPs, both in vitro and in vivo. As a volume in the highly successful Methods in Molecular Biology series, chapters contain introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible protocols, and tips on troubleshooting and avoiding known pitfalls. Concise and easy-to-use, Cell-Penetrating Peptides: Methods and Protocols, Second Edition hopes to raise relevant questions for further development.

Discusses new and established strategies for delivering peptides and antibodies through the blood-brain barrier. It reviews concepts on blood-brain barrier transport biology, assesses the utility and limitations of traditional brain drug delivery methods and describes new drug delivery techniques.

The Bad Bug was created from the materials assembled at the FDA website of the same name. This handbook provides basic facts regarding foodborne pathogenic microorganisms and natural toxins. It brings together in one place information from the Food & Drug Administration, the Centers for Disease Control & Prevention, the USDA Food Safety Inspection Service, and the National Institutes of Health.

The MPSA international conference is held in a different country every two years. It is devoted to methods of determining protein structure with emphasis on chemistry and sequence analysis. Until the ninth conference, MPSA was an acronym for Methods in Protein Sequence Analysis. To give the conference more flexibility and breadth, the Scientific Advisory Committee of the lOth MPSA decided to change the name to Methods in Protein Structure Analysis; however, the emphasis remains on "methods" and on "chemistry. " In fact, this is the only major conference that is devoted to methods. The MPSA conference is truly international, a fact clearly reflected by the composi tion of its Scientific Advisory Committee. The Scientific Advisory Committee oversees the scientific direction of the MPSA and elects the chairman of the conference. Members of the committee are elected by active members, based on scientific standing and activity. The chairman, subject to approval of the Scientific Advisory Committee, appoints the Organizing Committee. It is this latter committee that puts the conference together. The lectures of the MPSA have traditionally been published in a special proceedings issue. This is different from, and more detailed than, the special MPSA issue of the Journal of Protein Chemistry in which only a brief description of the talks is given in short papers and abstracts. In the I Oth MPSA, about half the talks are by invited speakers and the remainder were selected from submitted short papers and abstracts.

This volume focuses on pharmaceutical biotechnology as a key area of life sciences. The complete range of concepts, processes and technologies of biotechnology is applied in modern industrial pharmaceutical research, development and production. The results of genome sequencing and studies of biological-genetic function are combined with chemical, micro-electronic and microsystem technology to produce medical devices and diagnostic biochips. A multitude of biologically active molecules is expanded by additional novel structures created with newly arranged gene clusters and bio-catalytic chemical processes. New organisational structures in the co-operation of institutes, companies and networks enable faster knowledge and product development and immediate application of the results of research and process development. This book is the ideal source of information for scientists and engineers in research and development, for decision-makers in biotech, pharma and chemical corporations, as well as for research institutes, but also for founders of biotech companies and people working for venture capital corporations.