Motifs using

Ot-HehcalBundles. The a-helix is the most extensively studied protein stmctural motif. Because a-hehces form internal hydrogen bonds between the C=0 of residue i and the N—H of residue i + 4 (see Fig. 2), the individual helix is stabili2ed and can exist in isolation. Individual heUces can be manipulated as independent stmctural modules designed to associate in some predetermined manner. Often, a minimalist approach to the design of a-hehces has been taken. In this approach the goal is to obtain the desired stmctural motif using the simplest possible constmction. 

Different NHC Design Motifs Used in ROMP Initiators... 

Regarding bis-NHC chelating ligands, several structures that differ in the motifs used for the enlargement of the tether have been proposed as catalysts for the Mizoroki-Heck reaction. They range from non-functionalised aliphatic chains [23-25] to phenyl [26], biphenyl [27], binaphthyls [28] and to chains containing additional coordination positions like ethers [29], amines [30], and pyridines in an evolution towards pincer complexes [31-35], In most cases, the activity of aryl bromides in Mizoroki-Heck transformations was demonstrated to be from moderate to high, while the activation of chlorides was non-existent or poor (Scheme 6.7). 

Porphin dyes, 9 503 Porphine, as chelant, 5 709, 710 Porphyrin, 7 576 Porphyrin ligand, 14 554 Porphyrin motif, use in therapeutic strategies, 24 56 Porphyrins... 

COLl domain of type XXIII collagen contains multiple copies of a conserved KGD motif used for integrin-mediated cell adhesion by collagen type XVII. ... 

Despite many biochemical similarities between linker and core histones the proteins of these two groups differ in architecture, evolutionary origin, and function. Each of the four core histones has a characteristic histone fold domain. The latter is an old and ubiquitous structural motif used in DNA compaction and protein dimerization [3]. Linker histones do not have a histone fold. The canonical... 

One example is illustrated in Fig. 2, where the Motif used to explore the pocket is benzoic acid. Of the structures studied, a few had a strong base at a suitable distance to form a salt bridge by proton transfer. However, in the majority of cases, the carboxylic group was not directly proximate to a protein basic group but, in all cases, at least one basic residue was located... 

Examples of motifs used in composition of biologically active oligonucleotides... 

Figure 5.1 Examples of hydrogen bonding motifs used in side chain functionalizations of polymers (a) one-point complementary, (b, c) two-point dimerizing, (d, e) three-point complementary, (f) four-point dimerizing, (g) four-point complementary, and (h) six-point complementary hydrogen bonding motifs.

Figure 5.2 Examples of hydrogen bonding motifs used in supramolecular polymers dimerizing uieidopyrimidone (UPy) functionalized main chain supramolecular polymers (2A), simple one-point complementary hydrogen bonding interactions between pyridine and phenol (2B), and six-point complementary hydrogen bonding interaction between cyanuric acid and the Hamilton wedge receptor (2C).

Scheme 8.2 Formation of catalyst assemblies by selective pyri-dine-zinc(ii) coordinative motifs using zinc(ii)salphen complexes and different pyridylphosphine templates.

Figure 9.3 Representative approaches and structural motifs used for scaffold optimization.

In 2007, Betzer, Ardisson and co-workers reported their synthesis of discodermo-lide [64] following the Marshall disconnection strategy of C7-C8 acetylide addition and Suzuki cross-coupling at C14-05 (Scheme 32) [53, 54], The synthesis of the key subunits 160 (C1-C7), 161 (C8-C14) and 162 (C15-C24) demonstrated the versatility of the Hoppe crotyltitanation reaction [166-169] in the synthesis of polypropionate motifs, using the incorporated (Z)-0-enecarbamate to configure the requisite alkene substitution patterns [170, 171],... 

A unique alternative to the traditional C2 symmetric atopisomeric motif uses a paracyclophane backbone for the placement of the phosphino groups. 4,12-Bis(phosphino)-[2.2]-paracyclophane complexes, abbreviated as PhanePhos (5), have been reported to be highly active in a few classes of asymmetric hydrogenation. The synthesis is shown in Scheme 12.51.159,160... 

The two molecules in the asymmetric unit of Form I can be distinguished chemically. Neutral molecule A forms a C(6) using an amino-hydrogen and a carboxyl carbonyl (Fig. 2.19(c)) the zwitterion B has the same motif using an ammoniacal... 

In order to demonstrate that G-quadruplex conformational changes can be probed using Raman spectroscopy we first sought to investigate the intrinsic spectral features of this structural motif using an ofigo selected by Yoshida et al. [51] to form a G-quadruplex (GQ). GQ modified nanoshells (referred to as NS-GQ) were prepared the same way as NS-TBA (described above). 

The amphipathic helix, in which residues are spaced so that the helical periodicity places hydrophobic side chains on one side of the helix and hydrophilic side chains on the other, is a common structural motif used by the peripheral apolipoproteins to bind lipid (Segrest et al., 1992) it is also a structural element present in globular proteins (Perutz et al., 1965). 

Given the great structural diversity exhibited by the 1000 architectures of the folds, one might expect, from first principles, that certain architectures are more suited to particular biochemical functions than others. This is true in the case of certain submotifs, where it is apparent that particular conformations are suited to particular biochemical functions. One example is the helix-tum-helix motif used for DNA binding (Voet and Voet, 1995 Brandon and Tooze, 1999). 

Gan, H.H., Pasquali, S. and Schhck, T. (2003) Exploring the repertoire of RNA secondary motifs using graph theory implications for RNA design. Nucleic Acids Res., 31, 2926—2943. 

Fig. 4 A selection of some supromolecular motifs used to access supramolecular liquid crystals...

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