[Inhibition of RNA synthesis in vitro by antibodies against mononucleotides]

Antibodies against purine nucleotides were obtained from rabbits immunized with conjugates of bovine serum albumine with AMP or GMP. The antibodies purified by affinity chromatography on nucleoside monophosphate-human serum albumine-Sepharose columns inhibited RNA synthesis on native T4 phage DNA by E. coli RNA polymerase. The inhibition of transcription was due mainly to inhibition of the initiation stage of RNA synthesis.