Peptide structure solid-phase

Contents Introduction. - Structure Determination Amino Acid Analysis. Sequence Determination. Secondary and Tertiary Stmcture. - Peptide Synthesis Formation of the Peptide Bond. Protection of Functional Groups. Undesired Reactions during Synthesis. Racemization. Design of Schemes for Peptide Synthesis. Solid Phase Peptide Synthesis. - Methods of Facilitation. Analysis and Characterization of Synthetic Peptides. -Subject Index. 

Such a procedure is well established in the case of peptides, but solid-phase organic chemistry (SPOC) is more difficult. Optimization of the chemistry is required prior to library generation most of the time. Compound identification is complicated by the insolubility of the support. Release of the anchored structure in solution followed by standard spectroscopic analyses may impart delay and/or affect product integrity (9). A direct monitoring of supported organic reactions is thus preferable to the cleave and analyze methodology. Nevertheless, it presents several constraints. A common resin bead loaded at 0.8 mmol/g commonly produces nanomole quantities of the desired compound, and only 1% of the molecules are located at the outer surface of the bead (10). Very few materials, covalently bound to the insoluble support, are thus available for the analysis, which should ideally be nondestructive. 

Palmitic acid, structure of, 1062 Palmitoleic acid, structure of, 1062 PAM resin, solid-phase peptide synthesis and, 1037 Para (m), 519 Paraffin, 91 Parallel synthesis, 586 Parent peak (mass spectrum), 410 Partial charge, 36 Pasteur, Louis, 297, 307... 

Beausoleil, E., Truong, K.T., Kirshenbaum, K., and Zuckermann, R.N. Influence of monomer structural elements in hydrophilic peptoids. In Innovations and Perspectives in Solid Phase Synthesis and Combinatorial Libraries Peptides, Proteins, and Nucleic Acids, R. Epton (Ed.), 2001, Mayflower Scientific Press Kingswin-ford, UK, pp. 239-242. 

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 synthesis and crystal structure of the peptide nucleic acid (PNA) monomer 25 having cyanuric acid as nucleobase have been described. Monomer 25 can be directly used for the solid phase synthesis of PNA oligomers . 

For such an integrated research activity, differently modified peptides and proteins that carry modifications whose structure can be changed at will through synthesis are invaluable tools. Therefore, the synthesis of the lipidated peptides is an important theme. Lipidated peptides can typically not be accessed via standardized peptide synthesis methods. However, employing the synthetic tools developed and presented here, most types of lipidated peptides can now be synthesized and obtained in pure form. Even though solution-phase approaches still play a significant role in the synthesis of lipidated peptides, the recently developed solid-phase synthesis methods delineate the preferred strategy to access the majority of the required lipidated peptides. 

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