02655nas a2200325   4500008004100000022001400041245008700055210006900142260007700211300001400288520149300302653001301795653002001808653002001828653002301848100002701871700002401898700003301922700002101955700002201976700002501998700002102023700002602044700002402070700002302094700002602117700003502143700002802178856012302206       2013                        eng d  a1434-193X00aAnt-pro reverse-turn motif. structural features and conformational characteristics0 aAntpro reverseturn motif structural features and conformational   aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcJUN  a3529-35423 a<p>This article details the characteristic conformational features of the Ant-Pro reverse turn ? a folded pseudo -turn motif that displays a closed nine-membered-ring hydrogen-bonded network involving just two amino acid residues, namely anthranilic acid (Ant; a constrained -amino acid), and proline (Pro; a constrained -amino acid). The results from the extensive investigation of ten crystal structures and their NMR conformations in the solution state provide a clear idea about the conformational characteristics of the Ant-Pro reverse turn. The Ant and Pro residues, which form the turn segment, maintain a perfect antiperiplanar orientation throughout, leaving little possibility for the formation of the otherwise possible six-membered hydrogen-bonding that requires a coplanar disposition of the two amino acid residues, as clearly evident from investigation of several crystal structures. The closed hydrogen-bonded network observed in the Ant-Pro reverse turn motif, formed in the forward direction of the sequence (12 amino acid interactions) involving only two amino acid residues, is in stark contrast to the native -turns that involve four residues to form hydrogen-bonded network featuring backward 14 amino acid interactions. The readily available two-residue Ant-Pro motif raises the possibility of a practical utility, particularly in the application of rigidifying flexible peptide backbones by inserting the robust Ant-Pro reverse turn motifs into their backbone.</p>10aPeptides10aPeptidomimetics10aProtein folding10aProtein structures1 aThorat, Vijaykumar, H.1 aIngole, Tukaram, S.1 aVijayadas, Kuruppanthara, N.1 aNair, Roshna, V.1 aKale, Sangram, S.1 aRamesh, Veera, V. E.1 aDavis, Hilda, C.1 aPrabhakaran, Panchami1 aGonnade, Rajesh, G.1 aGawade, Rupesh, L.1 aPuranik, Vedavati, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/ant-pro-reverse-turn-motif-structural-features-and-conformational-characteristics-002051nas a2200253   4500008004100000022001400041245011600055210006900171260007700240300001400317490000700331520111700338653001601455653002601471653001401497653002101511653001301532653002601545100002101571700003301592700001401625700002801639856013001667       2014                        eng d  a1434-193X00aHeterogeneous foldamers from aliphatic-aromatic amino acid building blocks: current trends and future prospects0 aHeterogeneous foldamers from aliphaticaromatic amino acid buildi  aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcDEC  a7763-77800 v463 a<p>Chemists' constant pursuit of understanding of the underlying principles of nature's most intricate phenomenon such as protein folding has led to the development of the field of foldamers. The emergence of diverse classes of unnatural amino acid building blocks has unleashed countless opportunities to design, develop and explore the structural and functional aspects of synthetic peptides. One current trend in foldamer chemistry is the heterofoldamer approach, which involves systematic stoichiometric variation of various natural/unnatural amino acid residues, leading to conformational ordering with intriguing structural architectures. In this regard, the incorporation of aromatic amino acids provides efficient structural rigidification and tunability to the molecular scaffolds, which can exhibit a range of secondary structural features. Recent times have witnessed an upsurge of foldamers featuring aliphatic-aromatic residues with diverse structural propensities. This review is an effort to cover this rapidly developing field of foldamer science and also to envisage its future perspectives.</p>10aAmino acids10aConformation analysis10aFoldamers10ahydrogen bonding10aPeptides10aStacking interactions1 aNair, Roshna, V.1 aVijayadas, Kuruppanthara, N.1 aRoy, Arup1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/heterogeneous-foldamers-aliphatic-aromatic-amino-acid-building-blocks-current-trends-and-0