Kinked backbone

Figure 4.20 Structure of fluorinated polyamides containing kinked backbone [16].

The energy required to adjust the DNA to these receptor sites is given in Table VI. The DNA can kink equally well in both grooves with base pairs held at a distance sufficient for intercalation (Az = 6.76 A, ax = 0°) and for kinks (Az > 6.76 A, ax 0°). These receptor sites are constructed by operations on a pair of initially coincident base pairs. Each is rotated by +ax/2 and -ax/2 about a kink axis. This axis is perpendicular to the helix and dyad axes of the base, and parallel to the Cl (py)-Cl (pu) axis. It lies approximately along the C6(py)-C8(pu) axis. Then each base pair is rotated about the helix axis by +az/2 and -az/2 and separated by Az. The combinations of ax, az, and Az which permit the construction of a phosphate backbone defines families of receptor sites. With this approach, the base pairs adjacent to the BPDE are symmetrically... 

Fig. 24 Minimized structure of 47 showing the kink in the mPE backbone brought about by the binap moiety...

Chemical group used to disrupt the linearity of the backbone of molecules of MCLCPs. Note Examples are (a, b) rigid-kink or (c) crankshaft units. 

However, they varied in content of neutral sugars and extent of methyl-esterification. The presence of rham-nose in the backbone of pectin was believed to create kinks which probably disrupted helical stretches of the... 

In one recent study (15), isolation and purification of tobacco pectin yielded a series of related rhamnogalacturonans. All of these polysaccharides were found to have a backbone consisting of 4-linked a-D-galactopyranosyluronic acid residues interspersed with 2-linked L-rhamno-pyranosyl residues in a ratio of 16 1 (see Fig. 1). The presence of rhamnose in the backbone of pectin is believed to create kinks which probably disrupt helical stretches of the 4-linked a-D-galactopyranosyluronic acid... 

Proline is unique it is an imino acid because its side chain loops back to form a five-membered ring with its amino group, which causes proline to produce kinks in the polypeptide backbone. 

Due to the preference for a cis-amide bond[93] with the preceding residue of C2-substituted pseudoprolines, their incorporation results in a kink conformation of the peptide backbone, thus preventing peptide aggregation, self-association, or (3-structure formation. 

Figure 6. Stereogram of the metal ions and carbohydrate binding regions. The backbone atoms from Glu 8 to Asp 19 and from Ser 203 to Ala 11 plus designated side chains. The cis peptide bond is between Ala 207 and Asp 208, producing a distinct kink in this strand of /3-sheet.

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