Stacking and hydrogen bonding interactions between phenylalanine and guanine nucleotide: crystal structure of L-phenylalanine-7-methylguanosine-5'-monophosphate complex

[Overview of structural study on conformations and intermolecular interactions of biomolecules]

Information on the conformational feature and specific intermolecular interaction of biomolecules is important to understand the biological function and to develop device for treating disorder caused by the abnormal function. Thus the 3D structures of the biologically active molecules and the specific interactions with their target molecules at the atomic level have been investigated by various physicochemical approaches. Herein, the following five subjects are reviewed: (1) function-linked conformations of biomolecules including natural annular products, opioid peptides and neuropeptides; (2) π-π stacking interactions of tryptophan derivatives with coenzymes and nucleic acid bases; (3) mRNA cap recognition of eukaryotic initiation factor 4E and its regulation by 4E-binding protein; (4) conformational feature of histamine H2 receptor antagonists and design of cathepsin B inhibitors; (5) self-aggregation mechanism of tau protein and its inhibition.

A possible recognition mode of mRNA cap terminal structure by peptide: cooperative stacking and hydrogen-bond pairing interactions between m7GpppA and Trp-Leu-Glu

1H-NMR and fluorescence spectroscopic studies on the interaction between the Trp-Leu-Glu and m7GpppA have shown a specific binding mode, in which the pi-pi stacking interaction of the Trp indole ring and the hydrogen-bond pairing of Glu carboxyl side group with 7-methylguanine base are simultaneously formed.

A selective recognition mode of a nucleic acid base by an aromatic amino acid: L-phenylalanine-7-methylguanosine 5'-monophosphate stacking interaction

The conformation of 7-methylguanosine 5'-monophosphate (m7GMP) and its interaction with L-phenylalanine (Phe) have been investigated by X-ray crystallographic, 1H-nuclear magnetic resonance, and energy calculation methods. The N(7) methylation of the guanine base shifts m7GMP toward an anti--gauche, gauche conformation about the glycosyl and exocyclic C(4')-C(5') bonds, respectively. The prominent stacking observed between the benzene ring of Phe and guanine base of m7GMP is primarily due to the N(7) guarternization of the guanine base. The formation of a hydrogen bonding pair between the anionic carboxyl group and the guanine base further stabilizes this stacking interaction. The present results imply the importance of aromatic amino acids as a hallmark for the selective recognition of a nucleic acid base.