Native solid-phase synthesis

Native chemical ligation has been used successfully to couple two unprotected peptides together during solid phase synthesis, wherein one of the peptides is attached to the resin using a thioester linkage and the other peptide is introduced containing a cysteine at its N-terminal... 

Fig. 10.3-7 Native chemical ligations using C-terminal thioesters (e.g., 15) obtained tyrosine residues, (a) Reactive N-terminal using solid-phase synthesis techniques, cysteine mimics can be installed through (b) By changing the location of the tyrosine...

Template-associated synthetic proteins (TASP), proteins that have been designed and synthesized de novo. Artificial tertiary structures can be constructed by covalent attachment of secondary structure building blocks, e.g., /3-sheets, a-helices, and turns, to a topological template. This results in a non-linear architecture of protein modules that is nevertheless able to mimic native proteins. The combination of different secondary structure motifs in TASP provides, e.g., /Sa/3-structures, helix-bundles, or /3-barrel tertiary structures. The design of TASP makes extensive use of molecular modeling techniques. Solid-phase synthesis and spot synthesis have been used to obtain TASP [G. Tuchscherer, M. Mutter,... 

The peptide was then synthesized, and the product was shown to have the same biological activity as the natural material. Synthesis of the material in the cyclic (native) form is diflBcult and results in low yields. Schally and his colleagues (C3) have described the solid phase synthesis of GH-RIH in cyclic form in a highly purified state. They have shown that a high molecular weight compound formed during the cyclization... 

Liu P, Gui-Ling T, Kin-Sing L et al. (2002) Full enzymatic synthesis of a precursor of bioactive pentapeptide OGP (10-14) in organic solvents. Tetrahed Lett 43 2423-2425 Lloyd-Williams P, Giralt E (2000). Solid-phase convergent approaches to the synthesis of native peptides and proteins. In Kates SA, Alberido F (eds). Solid-phase synthesis a practical guide. Marcel Dekker, New York, pp 377-418... 

Abstract The utility of native chemical UgatiOTi (NCL) in the solution or solid phase synthesis of peptides, cyclic peptides, glycopeptides, and neoglycoconjugates is reviewed. In addition, the mechanistic details of inter- or intra-molecular NCLs are discussed from experimental and computational points of view. 

In this volume, state-of-the-art solid-phase synthesis is presented from different angles. Ranging from methodology development to application in the synthesis of complex native and designed structures, a complete overview is presented. 

Mezzato S, Schaffrath M, Unverzagt C (2005) An orthogonal double-linker resin fecilitates the eflScient solid-phase synthesis of complex type N-glycopeptide thioesters suitable for native chemical ligation. Angew Chem Int Ed 44 1650-1654... 

As mentioned above, the linker chosen for the solid-phase synthesis of lipidated peptides is of utmost importance. High concentrations of acid during the synthesis or for the release of the peptide from the solid support should be avoided to keep the isoprenoid group intact. In case a palmitoyl group is present, different conditions for the Fmoc deprotection and the coupling of amino acids should be used to minimize a nucleophilic attack to the thioester as well as an S- to JyT-acyl shift. Finally, the linker should be able to afford the desired peptide as a C-terminal methyl ester in case this functionality is present at the native sequence. 

Fig. 3 Important 19F-labelled amino acids, (a) Compounds that are wo-steric to native amino acids can be incorporated into proteins biosynthetically, but they possess too many degrees of torsional freedom to be useful for ssNMR structure analysis, (b) In these artificial amino acids the 19F-reporter group is rigidly attached to the peptide backbone. They can be incorporated by solid-phase peptide synthesis, but some problems can arise due to racemisation (4F-Phg, 4CF3-Phg), steric hindrance of coupling (F3-Aib) or HF elimination (fluoro-Ala, F3-Ala). 4F-Phg is additionally problematic due to an ambiguity of the side-chain rotamer. The preferred 19F-labels for ssNMR structure analysis are CF3-Bpg and CF3-Phg (as suitable substitutes for Leu, lie, Met, Val and Ala), as well as F3-Aib and CF3-MePro...

The assembly of the p- and y-amino-acid building blocks to peptidic chains was achieved by simply using the established methods of peptide synthesis - in solution [6], on solid phase [11], or in a synthesizer machine [39] also, the so-called native ligation can be applied with p-peptides [54]. Furthermore, the methods of analyzing and studying the structures of a-peptides and natural proteins can mostiy be applied to P-peptides as well (the same is true for y-peptides [51,55-60]). These methods are CD [35,37] and NMR [6, 49] spectroscopy, mass spectrometry [27,35], X-ray analysis [6,21,24,25,36], molecular dynamics (MD) calculations [9,13,18,31,38] and biological investigations [6, 15,20,26,30,41-43,45,46,48]. All of this sounds like routine, but the results are rather spectacular. 

Lu W, Qasim MA, Kent SBH. Comparative total syntheses of turkey ovomucoid third domain by both stepwise solid phase peptide synthesis and native chemical ligation. J. Am. Chem. Soc. 1996 118 8518-8523. 

CHO Chinese hamster ovary NCL native chemical ligation SPPS solid-phase peptide synthesis... 

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