RNA sulfurtransferase activity in rat liver and chemically induced hepatomas.

RNA sulfurtransferase activity has been detected in rat liver and in hepatomas from rats fed a diet containing 0.06% 3'-methyl-4-dimethylaminoazobenzene for 14 to 18 weeks. The reaction measured was the transfer of sulfur from cysteine to acceptor sites in Escherichia coli B transfer RNA (tRNA). Specific activities of the enzymes in liver and hepatoma supernatant fractions were similar, as were the rates and extents of sulfur transfer to tRNA. DEAE-cellulose chromatography of digests of the [35S]tRNA reaction products revealed 3 peaks associated with nucleotide material, the amounts of these peaks differing in tRNA from liver and hepatoma systems. This may suggest differences in specific sulfurtransferases in these tissues.