The simplest proline-containing peptides PG, GP, PGP, and GPGG: regulatory activity and possible sources of biosynthesis.

Our own data and data from the literature on the regulatory role of the simplest proline-containing peptides GP, PG, PGP, GPGG, and cyclic-PG are summarized. These peptides are involved in homeostasis of gastric mucosa and the anticoagulant and fibrinolytic potential of blood plasma. They also potentiate memory consolidation processes in the central nervous system. The most probable sources of these peptides are polypeptide precursors of collagen, elastin, and enterostatin.