ABSTRACT
Aspartic proteinases create a family of enzymes which are widely distributed in organisms and accomplish various functions. Despite this broad functional variety and chemical differences, aspartic proteinases share certain common features, based on which particular enzymes are assigned as members of the aspartic proteinase family. The mature aspartic proteinase consists of a chain of approximately 300 to 350 amino acid residues, with the resulting molecular weight between 30,000 to 40,000 daltons, often depending on the degree of glycosylation. The primary structures of zymogens of aspartic proteinases are formed by several distinct regions. The similarity in the structure of aspartic proteinases is most striking when examining the three-dimensional structures of their active sites. The similarity of aspartic proteinase structures, on one side, and the diversity of their functions, as well as cellular sorting and targeting on the other side, motivated a long line of research.
