The cooperativity of cation–π and π–π interactions

A first-principles investigation of histidine and its ionic counterparts

“…Further, frequency calculations at B3LYP/6-31G(d) level of theory characterized all monomers as minima on the PES. From the literature, it is well known that the M05-2X functional is suitable for treating non-covalent interactions [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. In our previous studies of phenylalanine, tyrosine and tryptophan monomers, we have also found the M05-2X functional to give satisfactory results [17][18][19].…”

“…Chakrabarti et al [20] reported that the His ring interacts with other aromatic and basic residues and forms hydrogen bonds (HBs) with polar and charged (both negative and positive) residues in proteins. Recent studies on the cooperativity of non-covalent interactions reveal that the manifestation of cooperativity is essential to understand various phenomena such as formation of supramolecular assemblies, catalysis and biological functions [1,[21][22][23][24]. His is an important model for the understanding of cation-π interactions due to its imidazole side chain [25][26][27][28][29][30][31][32][33][34][35][36].…”

The effect of ring annelation to benzene on cation-π interactions: DFT study

“…Recently, Vijay and Sastry have investigated, using ab initio method, the binding of Li + and Mg 2+ with the p-face of linear and cyclic unsaturated hydrocarbons to understand the size dependence on cation-p interactions [22]. Sastry and co-workers have provided new insights on cooperativity of cation-p and p-p interactions using quantum chemical calculations [23][24][25].…”

The Importance of Being Aromatic: π Interactions in Sodium Symporters

“…Aromatics can form two types of bonds: CH - π bonds between pairs of aromatic side chains in a T-stacking or an off-centered parallel orientation (6, 7), and cation – π bonds that occur between basic and aromatic side chains (8, 9). In general, CH-π bonds in proteins occur in networks and membrane proteins have a larger number of such networks than soluble proteins suggesting a role in membrane protein stability (10); There is computational evidence that there may be cooperatively between adjacent π-π and cation – π bonding sites (11). Aromatic bonds in LeuT transporters form networks between TM helices of membrane proteins: in vSGLT the network engages TM6 with TM1, 2, 3, and 10, and TM2 with TM10 (Figure 1A); and in LeuT the network ties TM1 with TM2 & TM6, TM3 with TM4, TM8 & TM10, TM4 with TM9, and TM5 with TM8 (Figure 1B).…”