Abstract: | The reaction between RNA and 4'hydroxymethyl-4,5',8-trimethylpsoralen has been studied. Both natural RNA and synthetic RNAs were used. The base specificity of the reaction was found to be the same in natural RNA, homopolymers, and mononucleotides. Uridine was found to be the most reactive base in all cases. The kinetics of formation and reversal of monoadducts and crosslinks has been examined. Paper electrophoretic conditions are described which provide a separation of the monoaddition and crosslinked photoproducts. The relative and absolute amounts of monoadducts and crosslinks can be determined very accurately with this system. Paper electrophoresis provides good separations of the different photoproducts. The mobilities of the products are a simple function of their molecular weights and charges. |