On the chemical and structural basis of membrane transducer and receptor systems

Evolution was based initially on polynucleotide systems. From these there developed the polynucleotide-based protein biosynthetic system. Membrane transducers are required by the most primitive cells and must have appeared at a very early stage. They would therefore also be expected to involve polynucleotides. There is substantial biochemical evidence for polynucleotide involvement in membrane transducers. There does not appear to be any reasonable alternative. Many biologically active substances show good matching to a polynucleotide receptor site that gives a good account of receptor function. There appears then to be no doubt that polynucleotides provide the basis of membrane transducers.