Structural-functional diversity of the natural oligopeptides.

Natural oligopeptides may regulate nearly all vital processes. To date, the chemical structures of many oligopeptides have been identified from >2000 organisms representing all the biological kingdoms. We have considered a number of mathematical (sequence length), chemical, physical, and biological features of an array of natural oligopeptides on the basis of the oligopeptide EROP-Moscow database (http://erop.inbi.ras.ru, 15,351 entries) data. There is the substantial difference of these substances from polypeptide molecules of proteins according to their physicochemical characteristics. These characteristics may be critical for understanding the molecular mechanisms of the action of oligopeptides that lead to the development of physiological effects.