Hydroxylation, supramolecular assembly

Figure 6 shows the proposed subunit assembly structure of the nicotinic acetylcholine receptor channel." The inner wall of the lower half part is surrounded by hydroxyl side chains from Ser and Thr, and by carboxylates or amides from Asp, Glu, and Gin at the mouth. Furthermore, a Lys residue seems to offer ion pairing with the carboxylate at the mouth. Considering the possibly similar stabilizing effect of ether and hydroxyl groups to cations, the proposed artificial supramolecular channel could be regarded as a good model of the acetylcholine receptor channel, which selects cations over anions, but does not discriminate between alkali metals. 

Su et al. (Xiao et al., 2008) fabricated a new type of thermotropic liquid-crystalline photosensitive supramolecular ionic self-assembly of polyelectrolyte and functional unit azobenzene IL crystal (azo-ILC), where the thermal and phase behaviors can be modulated by changing the spacer length (methylene units in azo). Ma et al. (Ma et al., 2008) found that the addition of very small amounts of an alcohol or water into tri-n-decylmethylphosphonium chloride and bromide salts (IPlOX) induced the formation of liquid crystalline, where strong association between the hydroxyl groups of alcohol or water and the head groups of IPlOX is indicated. 

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