The association of two α-globin chains with two βS-globin subunits forms hemoglobin S which undergoes non-covalent polymerization due to abnormal intermolecular contacts under low oxygen conditions.
Uncoordinated aqueous molecules and the adjacent 3-aba oxygen atoms form intermolecular hydrogen bonds.
It was expected that the PBA-a/PEO blends would be miscible since PBA-a possesses a great number of phenolic hydroxyls in the molecular backbone, which are potential to form the intermolecular hydrogen bonding interactions with oxygen atoms of PEO and thus would fulfill the miscibility of the blends.
Although the involvement of non polar residues makes the interactions to be hydrophobic in nature but the strong intermolecular hydrogen bond between carbonyl oxygen atom of Arg257 and N2 atom of creatinine (2.85 Å, 124.36°), makes the electrostatic interaction as the primary binding force responsible for the retention of toxin in the plasma.
The strong O H···O intermolecular interactions (A– G) of all structures [except those in tetragonal space groups (H– J ], can be described by only three graph set motifs: linear C11 6) chains, involving the O1 and O3 oxygens, planar (inversion related) or twisted (2-fold axis related) R22(10) dimers, and C11 5) 21-mediated chains.
The designed mechanism involves activation of the chemiluminescent moiety by intracellular oxygen free radicals and intermolecular energy transfer of the excited state energy to the photochromic moiety to result in release of the drug to allow the desired pharmacological effect to occur.
This makes the phenoxyphenol oxygen poorly reactive for intermolecular interactions including hydrogen bonding.
However, there is one important intermolecular interaction specific to molecules containing an oxygen, nitrogen, or fluorine atom that is attached to a hydrogen atom.
The H3A1 methyl group is anchored by intermolecular hydrogen bonds with the backbone carbonyl oxygen atoms of residues P347 and G349 (Fig. 2F, in which the H3A1 backbone nitrogen supplies two hydrogen bonds) and by nonpolar hydrophobic interactions between the H3A1 methyl group and the side chains of L325, P347 and W351 in PHD1KDM5B (Fig. 2G).
The N terminus of the peptide was anchored through intermolecular H-bonds with the backbone carbonyl oxygen atoms of residues P331 G333 (Fig 3B).
