Precursor polyproteins in endocrine and neuroendocrine systems.

The biosynthesis of neuro and hormonal peptides is in a state of rapid progress. The development of protein microsequencing is making it possible to characterize more and more new important molecules with nanomolar quantities, while the DNA structural studies favor the sequencing of the precursors of all these new peptides. These precursors are often polyproteins containing more than one active end-product. Their maturation processes are following a highly similar pattern with cleavage of the precursors at sites characterized by the presence of pairs of basic amino acid as noted in 1967-68 for the LPH and the pro-insulin models. This now constitutes a general concept which has good chances to be applicable to all the exciting neuro and hormonal peptides recently identified or yet to be discovered.