Do anionic gold clusters modify conventional hydrogen bonds? The interaction of anionic Au(n) (n = 2-4) with the adenine-uracil base pair.
Density functional approximation (B3LYP) calculations have been used in order to analyze the interaction of gold anionic clusters (Au(n) with n = 2-4) with uracil ([uracil-Au(n)](-1)), adenine ([adenine-Au(n)](-1)), and the adenine-uracil base pair ([uracil-adenine-Au(n)](-1)). It was found that there is only one stable isomer for [uracil-Au(2)](-1) and [uracil-Au(3)](-1), whereas there are two or more stable structures for [uracil-Au(4)](-1), [adenine-Au(n)](-1), and [uracil-adenine-Au(n)](-1). For all these systems, nonconventional hydrogen bonds are formed. Strengthening the bond between anionic gold clusters and the nitrogen base pair weakens the conventional hydrogen bond of the adenine-uracil base pair. This destabilization is not very strong (2-4 kcal/mol) and is at the limits of calculations, but anionic gold clusters bound in between the uracil-adenine base pair indicate that gold anionic clusters may dissociate it. These results will be useful for further experimental studies and may be important for future applications.
Martínez
Ana
A
Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior s/n, C. U., P.O. Box 70-360, Coyoacan, 04510.
D000225:Adenine / Q000737:chemistry*; D020029:Base Pairing / Q000187:drug effects; D004247:DNA / Q000737:chemistry; D004583:Electrons; D006046:Gold / Q000737:chemistry* / Q000494:pharmacology; D006860:Hydrogen Bonding; D008958:Models, Molecular; D014498:Uracil / Q000737:chemistry*
D014498:Uracil; D006046:Gold; D004247:DNA; D000225:Adenine