Cooperative H-bonds

Motion of large groups at protein surface may require participation of adjacent bulk solvent (e.g., in cooperative H-bond rearrangements)... 

However, despite its widespread popularity in material science, PNIPAM has inherent disadvantages such as an irreversible phase transition and, for short polymers, a significant influence of end-groups on the thermal behavior. Moreover, strictly speaking, PNIPAM is not a bio-inert polymer. Indeed, the presence of multiple secondary amide functions in the molecular stracture of PNIPAM may lead to the formation of cooperative H-bonding interactions with other amide polymers, in particular with proteins. Thus, the design of new types of thermoresponsive polymers is a cracial topic in contemporary polymer chemistry. 

Table 1 summarizes the results for three other systems for which solvent effects have been investigated the Gonzalez-Rodriguez H-bonded tetra-mers shown in Fig. 13A the cooperative H-bonded complex shown... 

The analysis of the photocurrent responses on the basis of Equations (11.45) and (11.46) appears consistent with the results obtained by other spectroscopic techniques in relation to the potential dependence of the metalloporphyrin coverage. However, the physical meaning of the parameters associated with the Langmuir isotherm must be considered cautiously. The contribution of aggregation, interfacial protonation and cooperative H-bonding associated with the adsorption... 

Another very important point in this type of study is the purification technique adapted to ionic polysaccharides, which involves the exchange of multivalent counterions with monovalent ones and the prevention of aggregate formation mainly due to the large amount of—OH groups in polysaccharides forming cooperative H-bonds [19]. 

Kriz J, Dybal J (2005) Cooperative H-bonds of macromolecules. 1. Binding of low-molecular-weight ligands to polymers. J Phys Chem B 109(28) 13436-13444. doi 10. 1021/jp051373v... 

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