Crystal structure of 3-(adenin-9-yl)propionhistamide hydrochloride monohydrate and the role of protonation in protein-nucleic acid interactions☆

Structure of 9-{2-[(4-imidazolyl)methylthio]ethyl}adenine

“…This is in contrast with the stacking interaction between the protonated imidazolyl group and the adenine moiety in the crystal of 3-(9-adeninyl)propionhistamide hydrochloride. Such a difference in interaction patterns explains well the experiments in solution; the biological consequence of this has already been mentioned in a previous paper (Takenaka, Takimoto & Sasada, 1984).…”

“…As a model of the interaction between histidine and adenine, we have determined the structure of 3-(9-adeninyl)propionhistamide hydrochloride by X-ray analysis and found that the imidazolium group stacks with the adenine moiety in the crystal 0108-2701/86/050601-03501.50 (Takenaka, Takimoto & Sasada, 1984). Changes in UV and NMR spectra on mixing histamine and adenine derivatives are different between acidic and neutral solutions (Takenaka, Takimoto & Sasada, 1984). In order to reveal the structural basis of the difference, we have determined the crystal structure of the title compound in which the imidazolyl group is not protonated.…”

Structure of 1-(2-hydroxyethyl)cytosine

“…To reveal elementary binding patterns in protein-nucleic acid interactions, we have investigated 0108-2701/85/091354-03501.50 the structures of model crystals that contain nucleic acid base and an amino-acid side group: carboxyl group (Fujita, Takenaka & Sasada, 1982, 1984aTakenaka & Sasada, 1982b), carbamoyl group (Fujita, Takenaka & Sasada, 1984b,c, 1985Takimoto, Takenaka & Sasada, 1981, indolyl group (Ohki, Takenaka, Shimanouchi & Sasada, 1977) and imidazolyl group (Takenaka, Takimoto & Sasada, 1984). The hydroxyl group is also a functional group which could play a role in the protein-nucleic acid interactions.…”