Development Of Solid-phase Peptide Synthesis Research Articles

Stepwise Construction of Disulfides in Peptides.

The disulfide bond plays an important role in biological systems. It defines global conformation, and ultimately the biological activity and stability of the peptide or protein. It is frequently present, singly or multiply, in biologically important peptide hormones and toxins. Numerous disulfide-containing peptides have been approved by the regulatory agencies as marketed drugs. Chemical synthesis is one of the prerequisite tools needed to gain deep insights into the structure-function relationships of these biomolecules. Along with the development of solid-phase peptide synthesis, a number of methods of disulfide construction have been established. This minireview will focus on the regiospecific, stepwise construction of multiple disulfides used in the chemical synthesis of peptides. We intend for this article to serve a reference for peptide chemists conducting complex peptide syntheses and also hope to stimulate the future development of disulfide methodologies.

Automated Solid-Phase Peptide Synthesis.

The development of solid-phase peptide synthesis by Bruce Merrifield paved the way for a synthesis carried out by machines. Automated peptide synthesis is a fast and convenient way of synthesizing many peptides simultaneously. This chapter tries to give a general guidance for the development of synthesis protocols for the peptide synthesizer. It also provides some suggestions for the modification of the synthesized peptides. Additionally, many examples of possible challenges during and after the synthesis are given in order to support the reader in finding the best synthesis strategy. Numerous references are given to many of the described matters.

The 9-Fluorenylmethoxycarbonyl (Fmoc) Group in Chemical Peptide Synthesis – Its Past, Present, and Future

The chemical formation of the peptide bond has long fascinated and challenged organic chemists. It requires not only the activation of the carboxyl group of an amino acid but also the protection of the Nα-amino group. The more than a century of continuous development of ever-improved protecting group chemistry has been married to dramatic advances in the chemical synthesis of peptides that, itself, was substantially enhanced by the development of solid-phase peptide synthesis by R. B. Merrifield in the 1960s. While the latter technology has continued to undergo further refinement and improvement in both its chemistry and automation, the development of the base-labile 9-fluorenylmethoxycarbonyl (Fmoc) group and its integration into current synthesis methods is considered a major landmark in the history of the chemical synthesis of peptides. The many beneficial attributes of the Fmoc group, which have yet to be surpassed by any other Nα-protecting group, allow very rapid and highly efficient synthesis of peptides, including ones of significant size and complexity, making it an even more valuable resource for research in the post-genomic world. This review charts the development and use of this Nα-protecting group and its adaptation to address the need for more green chemical peptide synthesis processes.

Chemical Modification of Cellulose Membranes for SPOT Synthesis

Since the development of solid-phase peptide synthesis in the 1960s, many laboratories have modified the technology for the production of peptide arrays to facilitate the discovery of novel peptide mimetics and therapeutics. One of these, known as SPOT synthesis, enables parallel peptide synthesis on cellulose paper sheets and has several advantages over other peptide arrays methods. Today, the SPOT technique remains one of the most frequently used methods for synthesis and screening of peptides on arrays. Although polypropylene and glass can be used for the preparation of peptide arrays, the most commonly used material for SPOT membranes is cellulose. Critical to the success of the SPOT synthesis is the ability to modify a cellulose membrane to make it more suitable for solid-phase peptide synthesis of peptides and their analogues. In this review, we highlight the current range of chemical modifications of cellulose that have been developed to enable SPOT synthesis and further enhance its impact on peptide drug discovery. This will contribute to further chemical modifications and applications of SPOT synthesis for peptide arrays and peptide therapeutic screening.

Quest for the chemical synthesis of proteins.

The chemical synthesis of proteins has been the wish of chemists since the early 19th century. There were decisive methodological steps necessary to accomplish this aim. Cornerstones were the introduction of the Z-protecting group of Bergmann and Zervas, the development of Solid-phase Peptide Synthesis of Merrifield, and the establishment of Native Chemical Ligation by Kent. Chemical synthesis of proteins has now become generally applicable technique for the synthesis of proteins with tailor made properties which can be applied not only in vitro but also in vivo .Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

The early years: Working at the bench with Bruce (1957–1959)

Having arrived at Rockefeller in the fall of 1958, I began to seek a suitable laboratory to pursue my interest in organic chemistry. The group of Wayne Woolley, together with Bruce Merrifield and John Stewart, seemed to fit my needs, and the presence of a cute technician in Bruce's lab helped to solidify the decision. So I became Dr. Woolley's first (and only) graduate student. The project was to synthesize imidazole derivatives with substrate-specific catalytic activity for the hydrolysis of carboxylic acid esters carrying aromatic side chains. Although the goal of mimicking specific enzyme catalysis was not achieved, I learned a great deal about heterocyclic chemistry. Bruce showed a keen interest in all that I did, and provided more assistance and personal mentoring than anyone else. I married Bruce's cute technician, Sibil Dale, after she left Rockefeller. Her close working relationship with Bruce and her superior memory enable her to write in a more personal account about the early years of Bruce's development of solid-phase peptide synthesis. Sibil's account follows. Bruce gave me my first job when I was just out of college in 1957. I worked as his research technician for 2 years. We shared a lab, along with George Tritch, on the fourth floor of Flexner Hall. The first thing Bruce did in the morning was to turn on the hot water tap to make instant coffee. Once, when I questioned this practice, he replied that he wanted to make sure he got all of his minerals. As soon as I started working with Bruce he taught me some lessons about the cost of research. One day when I was weighing some serine, I poured out too much on the scale and used the spatula to discard the excess in the sink. “You just threw away $65 worth of serine,” Bruce complained. At another time I dropped a sintered glass funnel. Bruce took me down the hall to see Dr. Woolley, the chair of the lab group, who declared that the broken object was worth its weight in gold. Bruce and I worked side-by-side at the same lab bench. As we worked we talked about work, our personal lives, and what we enjoyed in life. Several of us in the department liked to do puzzles while performing such mechanical tasks as evaporating. Bruce stumped us all with his thinking outside the box when one day he came in with the following number puzzle: 42, 51, 59, 68, and asked us what the next number should be. We all assumed it was some kind of mathematical progression and in vain tried to add, subtract, divide, and multiply to identify a pattern. When none of us could find the answer, Bruce announced that these were the subway stops of the Lexington local, a train that many of us, including myself, took to work. It was at the bench that I first heard Bruce mention the idea of linking amino acids into peptides by utilizing a solid support resin. In theory, the concept sounded so simple that I immediately expressed my doubts about the project. I was not the only skeptic. One day, at a graduation dinner, I was seated next to the Nobel Laureate Fritz Lipmann1 who inquired about what Bruce was currently working on. I explained Bruce's idea to Lipmann who said something about bacteria being able to do a much better job. When I repeated this later to Bruce, he seemed amused by Lipmann's comment. Despite the skeptics who surrounded him, Bruce stuck to his idea. I worked with him on the early stages of the development of the project but did not get any positive results. It took Bruce about 3 more years to bring his idea to fruition. In 1963, when John and I were living in Cambridge, England, where John was doing a post-doc, we received a letter from Bruce saying that he had successfully synthesized a peptide using the solid-phase method.

PAYING TRIBUTE TO BRUCE MERRIFIELD

MORE THAN 200 family members, friends, and former students and colleagues gathered at Rockefeller University on Nov. 13 to celebrate the scientific life and achievements of Nobel Laureate Robert Bruce Merrifield, who died in May at age 84 after a long illness (G&EN, May 29, page 8). During a symposium that was held as part of the event, Paul Nurse, president of Rockefeller University, and David Rockefeller, honorary chairman and life trustee of Rockefeller University, accepted an award, sponsored by the ACS Division of the History of Chemistry (HIST), for Merrifield's classic 1963 paper, titled Solid Phase Peptide Synthesis. I. The Synthesis of a Tetrapeptide ( J. Am. Chem. Soc. 1963 ,85, 2149) Merrifield is best known for the invention and development of solid-phase peptide synthesis, which revolutionized synthetic organic chemistry. His simple and ingenious idea reduced the time required for peptide synthesis from years to days and made many once-unthinkable syntheses possible. This research, done ...

Bradykinin in Solid-phase Peptide Synthesis

Bradykinin (Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg; BK) occupies a special place in the history of the development of solid-phase peptide synthesis (SPPS). It was the first biologically-active peptide to be synthesized by Merrifield using the new method. Since that time many hundreds of BK analogs have been synthesized by SPPS. Certain of these analogs show potential as drug candidates.

Stimuli-sensitive hydrogels: ideal carriers for chronobiology and chronotherapy

The development of solid-phase peptide synthesis in the early 1960s and recombinant DNA technology in the early 1970s boosted the scientific interest of utilizing proteins and peptides as potential therapeutic agents to battle poorly controlled diseases. While there has been rapid progress in the development and synthesis of new proteins and peptides as potential therapeutic agents, the formulation and development of the associated delivery systems is lacking. The development of delivery systems is equally important due to the problems of stability, low bioavailability and short half-life of proteins and peptides. The main problem in this field is that low stability leads to low bioavailability. In this review we draw attention to chrono-pharmacological drug-delivery systems, which can be used to match the delivery of therapeutic agents with the biological rhythm. They are very important especially in endocrinology and in vaccine therapy. We show that the treatment of hypopituitary dwarfism by administration of human growth-hormone-releasing hormone (GHRH) is more effective when GHRH is administered in a pulsatile manner that exhibits a period characteristic of the patient's circadian rhythm. Here we examine how to design novel chrono-pharmacological drug-delivery systems that should be able to release the therapeutic agents at predetermined intervals.

1] Concept and early development of solid-phase peptide synthesis

There are several reasons for the success of the solid-phase approach to peptide synthesis. The first is the ease of the procedure, the acceleration of the overall process, and the ability to achieve good yields of purified products. The second was the unanticipated discovery of many new biologically active peptides and the expanded need for synthetic peptides to help solve problems in virtually all disciplines of biology. In many cases, the solid-phase technique has been the method of choice. This approach, of course, does not replace the classic solution synthesis methods, but rather supplements them. The choice of techniques depends on the objectives of the synthesis. When carefully worked out, the solution methods can give high yields of highly purified products in large quantities. Many superb syntheses of active peptides have been achieved in this way. The solid-phase method has also yielded many large active peptides. It is particularly useful when large numbers of analogs, in relatively small quantities, are required as in structure-function studies on hormones, growth factors, antibiotics, and other biologically active peptides or for determining the antigenic epitopes of proteins. In addition, it has on occasion been scaled up for production of kilogram quantities. One of the unique uses of solid-phase synthesis has been the synthesis of peptide libraries. Most of the work on this new field in which thousands or millions of peptides are prepared simultaneously has been by solid-phase methods. This new technique is proving to be of great practical importance in rapid drug discovery of peptide, peptide mimetic, and nonpeptide compounds. Developments in screening methods now allow the examination of large numbers of compounds, and active products with structures unpredictable from natural product sequences are being found in this way. The properties of the solid-phase system, the changes in the chemistry, and the applications of the technique to biological problems are discussed in detail in subsequent articles of this volume.