<p>The beauty of the wide functionality of proteins and peptides in Nature is determined by their ability to adopt three-dimensional structures. This thesis describes artificial molecules developed to mimic secondary structures similar to those found crucial for biological activities.</p><p>In the first part of this thesis, we focused on post-translational modifications of a class of unnatural oligomers known as <i>β</i>-peptides. Through the design and synthesis of a glycosylated <i>β</i><sup>3</sup>-peptide, the first such hybrid conjugate was reported. In this first report, a rather unstable 3<sub>14</sub>-helical structure was found. Subsequently, a collection of six new glycosylated <i>β</i><sup>3</sup>-peptides was synthesized with the aim to optimize the helical stability in water.</p><p>The ability of natural proteins, i.e. lectins, to recognize the carbohydrate residue on these unnatural peptide backbones was investigated through a biomolecular recognition study.</p><p>The second part of this thesis concerns the design of conformationally homogeneous scaffolds, which could be of importance for biomedical applications. In paper V, four- and five-membered cyclic <i>all</i>-<i>β</i><sup>3</sup>-peptides were investigated for this purpose. In a subsequent paper, a completely different strategy was employed; herein, the ability of a single <i>β</i><sup>2</sup>-amino acid to restrict the conformational freedom of a cyclic α-peptide was studied. </p><p>In the third part of this thesis, we synthesized and investigated the folding propensities of novel backbone modified oligomers, i.e. <i>β</i>-peptoids (<i>N</i>-substituted <i>β</i>-Ala) with α-chiral side chains.</p><p>The collective results of these studies have established the procedures required for synthesis of glycosylated <i>β</i>-peptides and deepened our understanding of the factors governing folding among such oligomers. Moreover, it was established that <i>β</i>-amino acids can be a useful tool to increase conformational stability of cyclic peptides.</p>
| Identifer | oai:union.ndltd.org:UPSALLA/oai:DiVA.org:uu-7420 |
| Date | January 2006 |
| Creators | Norgren, Anna S. |
| Publisher | Uppsala University, Organic Chemistry, Uppsala : Acta Universitatis Upsaliensis |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Doctoral thesis, comprehensive summary, text |
| Relation | Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 ; 253 |
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