Homopolyribonucleotides, poly

These were the foundations on which our work was to be built. Joe Speyer and I were at the preparatory stage of the project (we had received all labeled amino acids ordered for the experiments and were determining the size of our polynucleotides) when the rumor of Nirenberg and Matthaei s momentous discovery reached us in August 1961. While studying the effect of RNAs from different sources on protein synthesis in a cell-free system from E. coli, they discovered that the homopolyribonucleotide poly(U) promoted the formation of the homopolypeptide polyphenylalanine. Thereby, the genetic code was broken. 

The double helical complex poly A poly U adsorbed onto MBSA has been used as immunogen in Fauve de Bourgogne rabbits (Nahon et al., I967) and in New Zealand White rabbits (Schwartz and Stollar, 1969). In both cases antibodies reacting specifically with poly A poly U were induced. These antibodies react also with the heterologous double-helical complex poly I poly C although they do not react with the separate homopolyribonucleotides poly I or poly C. In addition, the reaction is abolished if the complex is heated in the presence of formaldehyde. It is thus possible to conclude that these antibodies are specific for the double-stranded structure. 

Replication of synthetic homopolyribonucleotides has been studied by Friedemann Schneider and coworkers (Schneider et al., 1979 Heinrichs and Schneider, 1980). They studied RNA-synthesis at poly(A)-poly(U) templates by the unspecific RNA polymerase from E. coli in a stirred flow reactor. In general this reaction follows an overall autokatalytic kinetics. In the flow reactor the recycling process is replaced by an influx of A and an outflux of the material in the reactor. It is worth noticing that critical slowing down has been observed experimentally in this system. 

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