Differential Oxidation Of Bovine Serum Albumin Bsa And Its Effect On Protein Aggregation

A heat stable derivative of bovine serum albumin containing 300 residues of glycine added to 30 sites on the surface of the protein has been prepared. This derivative may be heated to 100° C for prolonged periods of time without aggregation. By comparison, native BSA aggregates at 62° C under similar conditions. The spatial arrangement of the added glycine peptides is probably responsible for the observed stabilization of the protein. Two possible arrangements of the added glycyl chains have been suggested. The first considers the chains to be fully extended and projecting into the surrounding solvent. The second envisions the added chains folded back along the protein surface. The experimental evidence greatly favors the second suggestion. Using trinitrobenzene sulfonic acid, it was determined that there were thirty reactive amino groups on the surface of native BSA. After denaturation of the protein with 8 M urea; 57 lysine groups could be reacted. Since the preparation of the polyglycyl derivative is carried out under similar reaction conditions to those employed with trinitrobenzene sulfonic acid, it is most likely that the amino groups on the surface of the molecule react with the N-carboxy glycine anhydride. The conformation characteristic of native BSA appears to be maintained in the derivative as indicated by various experimental measurements. The change in rotation associated with the acid expansion of BSA is paralleled by a similar but smaller change in the derivative. At pH 5.5 the specific rotation of the derivative was -47.7° and the native was -64.6°. The value for the polyglycyl BSA is several degrees lower than would be expected if it possessed the identical molar rotation as the native protein. A similar decrease in levorotation has been reported when ten moles of anionic detergent are bound to one mole of BSA The ultraviolet difference spectra observed by perturbing the native and derivative protein by pH and heat indicated that the main matrix of each protein was undergoing a similar transition. In all cases observed the derivative showed less change in optical density than did the native protein. If the glycine chains were folded back along the protein surface shielding some chromophoric groups from contact with the solvent, this decrease could be explained. The hydrodynamic measurements also support the suggestion that the structure of the protein core of the derivative is retained. The derivative undergoes the same reversible acid expansion as the native protein. Polyglycyl BSA with an S20 value of 3.85 at pH 2.5 regained its native conformation which had a sedimentation coefficient of 5.45 by dialysis against phosphate buffer at pH 6.3. By approximations that may be made from the diffusion coefficient, it was shown that the degree of hydration of the derivative could have a large variation depending upon the spatial arrangement of the added peptides. If the added peptides were folded, the hydration would be less than the native protein and if they were extended the hydration would be greater than the native protein. The hydration was evaluated by the determination of the buoyant density of polyglycyl BSA in a series of salt solutions. The values of the hydration of the protein-salt complex determined are as follows: in CsC1, 0.42 gm H2O/gm protein; in RbBr, 0.37 gm H2O/gm protein; and in KBr, 0.33 gm H2O/gm protein. The corresponding values of the hydration of the protein-salt complex for bovine mercaptalbumin reported by Ifft and Vinograd are as follows: in CsC1, 0.51 gm H2O/gm protein; in RbBr, 0.46 gm H2O/gm protein and in KBr, 0.37 gm H2O/gm protein. The decrease in hydration found in the derivative may be adequately explained by the change in the surface to volume ratio that would be expected if the added peptides were folded back along the protein surface. An approximate calculation of the surface to volume ratio of the derivative in this configuration gives a value of 0.83 that of the native protein. A similar calculation assuming that the chains are extended gives a ratio of 1.5. The decrease found is clearly more consistent with a molecule in which the added peptide chains are folded back along the protein surface. An increase of the activity of water accompanied by an increase in the hydration of the protein has been presented previously by Ifft and Vinograd, and was found to be valid for the hydration of the derivative. Considering the experimental evidence that has been presented, it is felt that the added polyglycyl chains are folded back along the surface of the protein. When they are in this configuration they form hydrogen bonds with groups on the surface of the protein and would cover some of the hydrophobic regions on the surface of the protein. Both of these effects would cause the derivative to be more stable than the native protein.

This volume explores experimental and computational approaches to measuring the most widely studied protein assemblies, including condensed liquid phases, aggregates, and crystals. The chapters in this book are organized into three parts: Part One looks at the techniques used to measure protein-protein interactions and equilibrium protein phases in dilute and concentrated protein solutions; Part Two describes methods to measure kinetics of aggregation and to characterize the assembled state; and Part Three details several different computational approaches that are currently used to help researchers understand protein self-assembly. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Thorough and cutting-edge, Protein Self-Assembly: Methods and Protocols is a valuable resource for researchers who are interested in learning more about this developing field.

Serum albumin is a large protein present in cow serum protein (BSA, Bovine Serum Albumin) rich in essential amino acids and compounds with disulfide bridges and thiol groups. This protein passes into breast milk from the bloodstream by diffusion, has antioxidant capacity and protects fats from oxidation. Albumin has the ability to inhibit tumor factors and bind to fat, mobilize them in the body to perform other functions such as obtaining energy or forming membranes. It is also able to block the conversion of angiotensin I into angiotensin II (vasoconstrictor) which gives it antihypertensive action. In addition, it has the ability to reduce cholesterol absorption, complex heavy metals and is an opioid agonist (acts on opioid receptors and promotes analgesia). BSA is the most studied and produced protein worldwide in the last 80 years. This protein brings large dividends to the world economy with a very prominent and favorable annual growth at a cost of 100 USD per gram. This book brings new contributions to the science and industry of this biopolymer. The audience of this book is very wide from students, teachers and researchers (doctors, pharmacists, biochemists and industrialists of this sector). Therefore, this book has a great future and many readers to whom it is addressed.

The book highlights recent developments in the field of spectroscopy by providing the readers with an updated and high-level of overview. The focus of this book is on the introduction to concepts of modern spectroscopic techniques, recent technological innovations in this field, and current examples of applications to molecules and materials relevant for academia and industry. The book will be beneficial to researchers from various branches of science and technology, and is intended to point them to modern techniques, which might be useful for their specific problems. Spectroscopic techniques, that are discussed include, UV-Visible absorption spectroscopy, XPS, Raman spectroscopy, SERS, TERS, CARS, IR absorption spectroscopy, SFG, LIBS, Quantum cascade laser (QCL) spectroscopy, fluorescence spectroscopy, ellipsometry, cavity-enhanced absorption spectroscopy, such as cavity ring-down spectroscopy (CRDS) and evanescent wave-CRDS both in gas and condensed phases, time-resolved spectroscopy etc. Applications introduced in the different chapters demonstrates the usefulness of the spectroscopic techniques for the characterization of fundamental properties of molecules, e.g. in connection with environmental impact, bio-activity, or usefulness for pharmaceutical drugs, and materials important e.g. for nano-science, nuclear chemistry, or bio-applications. The book presents how spectroscopic techniques can help to better understand substances, which have also great impact on questions of social and economic relevance (environment, alternative energy, etc.).

In this special volume on polymer particles, recent trends and developments in the synthesis of nano- to micron-sized polymer particles by radical polymerization (Emulsion, Miniemulsion, Microemulsion, and Dispersion Polymerizations) of vinyl monomers in environmentally friendly heterogeneous aqueous and supercritical carbon dioxide fluid media are reviewed by prominent worldwide researchers. In addition to the important challenges and possibilities with regards to design and preparation of functionalized polymer particles of controlled size, the topics described are of great current interest due to the increased awareness of environmental issues.

The first of its kind, All About Albumin summarizes the chemistry, genetics, metabolism, clinical implications, and commercial aspects of albumin. It provides the most up-to-date sequences, structures, and compositions of many species, and includes more than 2000 references. Includes up-to-date sequences, structures, and compositions of many species Reviews the protein chemistry, genetic control, and metabolism of albumin Covers medical and cell culture applications in vivo and in vitro, with a section on handling albumin in the laboratory Presents the relationship of albumin to its superfamily with an updated scheme for their evolution First complete coverage of all aspects of serum albumin in one volume, with more than 2000 references

An up-to-date overview of the dynamic field of whey protein utilization Whey Protein Production, Chemistry, Functionality and Applications explores the science and technology behind the rapidly increasing popularity of this most versatile of dairy by-products. With its richly nutritious qualities, whey protein has been widely used in the food industry for many years. The last decade has, however, seen manufacturers develop many innovative and exciting new applications for it, both in food and other areas. Taking account of these advances, this insightful work offers a full explanation of the technological and chemical breakthroughs that have made whey protein more in-demand than ever before. Topics covered include manufacturing technologies, thermal and chemical modifications, non-food uses, denaturation and interactions, and more. In its broad scope, the book encompasses: An up-to-date overview of recent developments and new applications Breakdowns of the chemical, nutritional, and functional properties of whey protein Commentary on the current and future outlooks of the whey protein market Examinations of the methods and manufacturing technologies that enable whey protein recovery A full guide to the numerous applications of whey protein in food production and other industries Whey Protein Production, Chemistry, Functionality and Applications is an unparalleled source of information on this highly adaptable and much sought-after commodity, and is essential reading for food and dairy scientists, researchers and graduate students, and professionals working in the food formulation and dairy processing industries.

The first edition of Protein Purification Protocols (1996), edited by Professor Shawn Doonan, rapidly became very successful. Professor Doonan achieved his aims of p- ducing a list of protocols that were invaluable to newcomers in protein purification and of significant benefit to established practitioners. Each chapter was written by an ex- rienced expert in the field. In the intervening time, a number of advances have w- ranted a second edition. However, in attempting to encompass the recent developments in several areas, the intention has been to expand on the original format, retaining the concepts that made the initial edition so successful. This is reflected in the structure of this second edition. I am indebted to Professor Doonan for his involvement in this new edition and the continuity that this brings. Each chapter that appeared in the original volume has been reviewed and updated to reflect advances and bring the topic into the 21st century. In many cases, this reflects new applications or new matrices available from vendors. Many of these have increased the performance and/or scope of the given method. Several new chapters have been introduced, including chapters on all the currently used protein fractionation and ch- matographic techniques. They introduce the theory and background for each method, providing lists of the equipment and reagents required for their successful execution, as well as a detailed description of how each is performed.

Although originally invented and employed by physicists, electron paramagnetic resonance (EPR) spectroscopy has proven to be a very efficient technique for studying a wide range of phenomena in many fields, such as chemistry, biochemistry, geology, archaeology, medicine, biotechnology, and environmental sciences. Acknowledging that not all studies require the same level of understanding of this technique, this book thus provides a practical treatise clearly oriented toward applications, which should be useful to students and researchers of various levels and disciplines. In this book, the principles of continuous wave EPR spectroscopy are progressively, but rigorously, introduced, with emphasis on interpretation of the collected spectra. Each chapter is followed by a section highlighting important points for applications, together with exercises solved at the end of the book. A glossary defines the main terms used in the book, and particular topics, whose knowledge is not required for understanding the main text, are developed in appendices for more inquisitive readers.