This three-dimensional conformation is held together by the interactions of the amino acids at different parts of the polypeptide chain with each other, and determines the activity of the protein.

The four dimensional space, means that the mankind the substance space( namely three dimensional space ) of the concrete activity, plus one more consciousness measurement ( time factor).

AIM Structure-Cytotoxic activity relationship and three -dimensional structures of diterpenoid tanshinones from Salvias have been studied.