Kinetic studies on the interaction of gold (III) with nucleic acids. IV. RNA-Au (III) system.
The kinetics of the interaction of Au(III) with whole yeast RNA has been studied using UV-spectrophotometry. The reaction is second order with respect to the nucleotide unit of RNA and first order with respect to Au(III) in the respective stoichiometry of 2 : 1. The effects of initial composition, temperature, ionic strength, pH and chloride ion on the kinetics have been studied. Activation energy is found to be 11.5 kcal/mol. Effect of ionic strength indicates that both the positively charged and neutral species of Au(III) take part in the rate limiting step, the former being dominant at low ionic strength. A plausible mechanism has been proposed which involves the interaction of two nucleotide units of RNA with one species of Au(III) in the rate limiting step.
D055598:Chemical Phenomena; D002621:Chemistry; D002712:Chlorides; D006046:Gold / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009994:Osmolar Concentration; D012313:RNA / Q000032:analysis; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
D002712:Chlorides; D012313:RNA; D006046:Gold