Activity of cardosins A and B in the presence of organic solvents

Cardosin A and cardosin B are two aspartic proteinases extracted from Cynara cardunculus L. stigma [1]. These enzymes show different specificities, although they prefer bonds between hydrophobic residues. In a previous work [2] we have shown that cardosins are stable and active in a biphasic (aqueous/organic) system. In this work we have investigated the stability and activity of cardosins A and B in monophasic systems. The solvents used were 1,1,1,3,3,3-hexafluoropropanol, ethyl acetate, n-hexane and mixtures of some of them. The activity test was performed with the synthetic peptide Leu-Ser-pnitro-Phe-Nle-Ala-Leu. We also tested the content of water in order to maintain the enzymes stable and active in monophasic organic solvents. The results show that these two enzymes are different in what concerns their stability/activity characteristics.