Peptide synthesis, automatic

Baru, M. B., Cherskii, V. V., Danilov, A. V., Moshnikov, S. A., and Mustaeva, L. G. (1995) Automatic SynChrom system for solid phase peptide synthesis and liquid column chromatography. 11. Application to solid phase peptide synthesis and liquid column chromatography. Russ. J. Bioorch. Chem. 21, 506—516. 

Birr, C. (1978) Automatization of the Merrifield peptide synthesis. n Aspects of the Merrifield Peptide Synthesis (Birr, C., ed.). Springer-Verlag, Berlin New York, pp. 72-80. 

Blaha, I., Zaoral, M., Krchnak, V., Jehnicka, J., Stepanek, J., and Kalousek, J. (1986) Automatic device for solid-phase peptide synthesis. Chem. Listy 80, 994. 

Schnorrenberg, G. and Gerhardt, H. (1989) Fully automatic simultaneous multiple peptide synthesis in micromolar scale Rapid synthesis of series of peptides for screening in biological assays. Tetrahedron 45, 7759-7764. 

Solid phase peptide synthesis[6, 7] (SPPS) is now an established methodology for the synthesis of small- to medium-sized peptides. Since the first reports on this technique in the early 1960s [3] several improvements in protecting groups, coupling reagents and solid supports have allowed access to a broad range of peptides in a routine and automatic manner. However, the synthesis of complex peptides... 

In laboratories where an automatic sequencing instrument is routinely used, it is worthwhile to apply it for the examination of synthetic materials, or at least of the final product of a synthesis. Shortcomings of the chain-building process, such as deletion of a residue (sometimes encountered in solid phase peptide synthesis) are uniquely recognized through sequencing. 

Each step from the chemical and practical view has its own problems and therefore will be discussed in detail later on in separate sections. The succession of cycles during a solid phase synthesis characterizes the various stages of the peptide elongation. Since all operations in the Merrifield method are often repeated, the procedure is predestined for automatic peptide synthesis. Consequently the first apparatus for this purpose had already been constructed in the incipience of the methodical development by R. B. Merrifield and J. M. Stuart [39] (see p. 72). 

The aspects discussed in the preceding section elucidated the part of work to be finished in batches before starting — more or less automatically — a Merrifield peptide synthesis with its returning cycles of operations on each stage of the process. 

Already in the incipience period of Merrifield s method it was demonstrated that the new idea included the possibility for automatization of most of the chemical operations necessary for peptide synthesis [39]. On this aspect was based a great part of the enthusiasm which still accompanies the development of the methodology to date Like a fata morgana all routine work in conventional peptide synthesis seemed to be transferable to a more or less automatically operating machine. The only remaining labor was to refill reagents and solvents, to maintain the instrument, and to reap the end product. 

All operations in solid-phase peptide synthesis have been automated. The reactions occur in a single reaction vessel, with reagents and wash solvents automatically added from reservoirs by mechanical pumps. Merrifield synthesized the nonapeptide bradykinin (page 503) in just 27 hours using this technique. And, in 1969, he used the automated synthesizer to prepare the enzyme ribonuclease (124 amino acid residues), the first enzyme to be prepared synthetically from its amino acid components. The synthesis, which required 369 chemical reactions and 11,391 steps, was completed in only six weeks. Automated computerized peptide synthesis, though still not without occasional problems, is now a fairly routine matter. 

Solid-phase chemistry is an efficient synthetic tool that, compared with solution-phase chemistry, simplifies the work-up of the reaction, allows the process to be driven to completion by using excess of reagents, and can be automatized [2a]. In recent years, many studies have been devoted to developing both surface-mediated and resin-supported synthesis. Today the solid-phase approach is not limited to peptides and oligonucleotides but is also used to synthesize molecules of lower molecular weight. 

At this time, a solid phase automatic peptide synthesizer was acquired, so we attempted total synthesis of Sh I. A solid phase synthesis of Ax I (antho-pleurin A) had previously been reported in an abstract (36). The synthetic Ax I possessed only 11% of the toxicity of the natural toxin. 

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