Stability of antiacanthain in aqueous - organic biphasic systems

Abstract

The use of organic solvents as reaction media for enzymatic reactions provides numerous industrially attractive advantages compared to traditional aqueous reaction systems. In organic media, the proteases synthesize peptide bonds due to the shift of the thermodynamic equilibria in favor of synthesis. The aim of this work was to study the stability of proteolytic enzyme of fruit of Bromelia antiacantha Bertol, (a plant that growns in Argentina) in biphasic organic media, for its application to the bioactive peptide synthesis. An experimental statistical design allowed to cluster different organic solvents, by its physical chemistry characteristics and to select one of each group. Antiacanthain stability in biphasic system (Tris-HCl (0.1M) pH 8- organic solvent) was assayed by means of incubation of pre-purified crude extract in the reaction mixture (30:70; 50:50 and 70:30) during 24h. Enzyme specific activity was determined using N-alpha-benzoyl-DL-arginine-p-nitroanilide (BApNA) as substrate. Antiacanthain in biphasic systems (aqueous-organic) at 50% showed increased stability than in buffer Tris-HCl (pH 8) (t1/2 = 8 h). In addition, initial activity and the profile stabilities of antiacanthain were activated for (50%) ethyl acetate and hexane; maintained for benzene, ethyl ether and dichloromethane (50%) and diminished for octane and chlorobenzene (50%), when they was compared whit buffer. Profiles stabilities of antiacanthain in biphasic aqueous-organic systems (30 and 70%) were maintained, except for chlorobenzene (70%).