System-theoretical (Holistic) approach to the modelling of structural-functional relationships of biomolecules and their evolution: an example of triterpene glycosides from sea cucumbers (Echinodermata, holothurioidea).

Triterpene glycosides from sea cucumbers (Holothurioidea, Echinodermata) are used as a model for studying the biochemical evolution for correlation between the glycoside membranolytic activity and biological functions. Concepts of evolutionary morphology are applied at the molecular level. The concept of Van-der-Klaauve's- Dullemeijer's system-theoretical (holistic) approach is used for the model of structural-functional relationships of the glycosides. Network diagrams of structural-functional relationships have been prepared for many glycosides. The diagrams correlate well with experimental data and show a very complex and flexible action of the natural selection on the structural fragments of the glycosides. The diagrams also show overlapping in the functional components that provide stability to the general structural plan of glycosides during evolution. The method may be applied to other biomolecules. Copyright 2000 Academic Press.