Conformational space oligomers

Figure 54. Drawing of the proposed helical conformation of oligomer 11 (n= 8), where R = Sn-Pr. Side (bottom left) and top (bottom right) view of the space-filling model of the crystal structure of pyridine—pyrimidine oligomer 11 (n = 8) in a helical conformation.

In principle, the chemistry in sidechains can be used to make oligomers more generally soluble, to add solubility contrast (see the solvent section below), to add the ability to pack structures together, to add the ability to bind ions, to name but a few capabilities. Chiral sidechains can add a chiral bias to a system, inducing an enantiomeric excess in an overall chiral shape. The side chain can significantly influence the overall conformational space as observed in (3-peptides. 

Chandrasekhar J, Saunders M, Jorgensen WL (2001) Effieitmt explmatimi of conformational space using the stochastic search method application to beta-peptide oligomers. J Comput Chem 22 1646-1654... 

Fig.1 A space-fiUing model showing the conformational equUihrium between hehcal and random coil states for a mPE oligomer (n=18). Side chains have been omitted for clarity...

The cooperative binding of O2 by hemoglobin and the allosteric effects in many enzymes require interaction between sites that are widely separated in space. The MWC model was proposed in 1965 to incorporate allosteric and conformational effects in an explanation of enzyme cooperativity. The seminal observation was that most cooperative proteins have several identical subunits (protomers) in each molecule (oligomer) this situation is imperative for binding cooperativity. The MWC model is defined as follows ... 

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