Dados do Trabalho

Título

PAPAIN ADSORPTION IN SUPERMACROPOROUS CATION EXCHANGERS

Introdução

Chromatographic techniques are present in most biomolecular purification processes. Among the methods used, ion exchange chromatography stands out, based on adsorption by electrostatic attraction. To improve purification processes, new adsorbents, such as cryogels, are being developed with high porosity that allows more viscous solutions. Given the above, this work objective was to evaluate papain's adsorption on cationic polymeric adsorbents.

Material e Métodos

The base cryogel matrix was prepared from a solution containing 7% acrylamide monomers, N, N'-methylene bisacrylamide, allyl glycidyl ether, added ammonium persulfate, and N, N, N', N' tetramethylethylenediamine. The solution was poured into 10 mL plastic syringes, placed in a thermostatic bath at -12 ºC for 24 hours, and dried in an oven at 60 ºC for approximately 48 hours. For functionalization, the cryogels produced were activated with Potassium Cuprate Diperiodate - K5[Cu (HIO6)2] and grafted with Acrylic Acid (AAc). The cationic nature of the activated matrices was evaluated by determining the point of zero charge (PZC). Papain was extracted from papaya latex. Approximately 1 g of latex was precipitated with 2 mL of NaCl solution (0.9 mol.L-1) and resuspended with 3 mL of water.

Resultados e Discussão

The PZC obtained for the produced adsorbent was equal to 4.37 due to the inclusion of acidic groups on the surface of the cryogel, resulting from the grafting with AAc. A wide buffer range (pH 4 to 9) was observed, which can be used for adsorption other proteins with an ideal pH within this range. The cryogels were placed in contact with the papain extract solution to evaluate efficiency. The adsorbed amount was determined using the Bradford method. The adsorbent produced had an adsorption capacity of 56.99 ± 0.06 mg of protein. g-1 of cryogel, about 3 times more than the non-functionalized adsorbent. The results indicate that the functionalization was efficient and that the matrices produced have potential for use in separation processes, eliminating some purification steps (precipitation, centrifugation, etc.) and reducing process costs.

Conclusão

The results indicate that the functionalization was efficient and that the matrices produced have the potential for use in protease purification processes by cation exchange.