Stacking, aromatic

Fig. 8. Comparison of the pterin-bound and -free structures. In the absence of pterin with the SEITU inhibitor in the active site (right), L-Arg binds in the pterin site. L-Arg is an excellent mimic for H4B owing to the similar H-bonding pattern with the heme propionate and Serl04, and the ability of the L-Arg guanidinium group to aromatically stack with Trp449.

Figure 2. Observed aromatic stacking between benzoic acid groups (center of picture) and protein amino acids.

Adams H, Hunter CA, Lawson KR, Perkins J, Spey SE, Urch CJ, Sanderson JM. A supra-molecular system for quantifying aromatic stacking interactions. Eur J Chem 2001 7 4863-4877. 

Results from these experiments indicate that the aromatic stacking interaction between complementary strands is probably not the factor responsible for the stabilization of the cross-linked product in aqueous media. Instead, the critical role played by interstrand H bonding in the stabilization of products 19-20 (and similarly 21-22) was clearly demonstrated by the high sequence specificity of the cross-linking reactions, as well as by the behavior of control strands 24 and 25 in the presence of 20. 

The remarkable thermodynamic stability of catenane 28 overcame a combination problem which should arise in self-assembly from a larger set of components. At least, formation of three component rings 32-34 is possible because their thermodynamic stability is comparable. Nevertheless, catenane 28 self-assembled as a sole product. This result shows that, having an ideal van der Waals separation (3.5 A) in its framework, only rectangular box 34 can be stabilized by filling its cavity with another copy of itself. Actually, the efficient aromatic stacking of four... 

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