Conformational change, propagation

In polymers, due to the constraint resulting from the connectivity of the chain, the local motions are usually too complicated to be described by a single isotropic correlation time x, as discussed in chapter 4. Indeed, fluorescence anisotropy decay experiments, which directly yield the orientation autocorrelation function, have shown that the experimental data obtained on anthracene-labelled polybutadiene and polyisoprene in solution or in the melt cannot be represented by simple motional models. To account for the connectivity of the polymer backbone, specific autocorrelation functions, based on models in which conformational changes propagate along the chain according to a damped diffusional process, have been derived for local chain... 

Fig. 18 Schematic of the conformational changes from mushroom to brush state that occur in graft-polymerized PDMAm during the chain propagation process...

If the conclusion is correct that the propagating cation is in a boat conformation, the a-side of all three anhydro sugars would present the same appearance to an entering monomer, and it would be understandable that the rate-determining feature would primarily involve conformational changes in the monomer. However, if the cation is in the conformation, C-l of the anhydromannose would be the... 

EMPs as Carriers of Molecules. In addition to measurable antigens, EMPs as other MPs, are also carriers of molecules. Conformationally changed prion proteins, believed to aid in the propagation of spongiform encephalopathies, have been detected on EMPs released by infected ECs [68]. This finding indicates that EMPs may be active players in the infectious process of spongiform encephalopathies. 

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