Kinetic model of the hydrolysis of polypeptides catalyzed by Alcalase ® immobilized on 10% glyoxyl-agarose

• Published in: Enzyme and microbial technology 2005-03, Vol.36 (4), p.555-564
• Main Authors: Tardioli, Paulo W., Sousa, Ruy, Giordano, Roberto C., Giordano, Raquel L.C.
• Format: Article
• Language: English
• Subjects: Alcalase ®-glyoxyl; Biological and medical sciences; Biotechnology; Cheese whey; Competitive inhibition; Enzyme engineering; Fundamental and applied biological sciences. Psychology; Methods. Procedures. Technologies; Michaelis–Menten model; Miscellaneous; Polypeptide hydrolysis
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2004.12.002

The sequential hydrolysis of cheese whey proteins can improve physical, chemical and organoleptic properties of this dairy by-product, increasing its applications in the food and pharmaceutical industry. The hydrolysis of polypeptides (50 °C, pH 9.5), catalyzed by Alcalase ® immobilized on 10% agarose (weight basis), activated with linear aliphatic aldehyde groups (glyoxyl-agarose), is studied here. The reaction substrate (polypeptides) is the product of a previous, sequential hydrolyses of cheese whey proteins by trypsin, chymotrypsin and carboxypeptidase A. A Michaelis–Menten model with product inhibition was fitted to the experimental data after long-term batch assays. Kinetic parameters k, K M and K I were correlated with respect to the degree of hydrolysis of the substrate in the upstream proteolyses, thus providing a general, semi-empirical rate equation. With this approach, the kinetic model may be included in process optimization algorithms, which may span different regions of operation for the proteolytic reactors. Parameters k, K M and K I ranged from 0.005 to 0.029 mmol/min/U BAEE, from 4.0 to 13.7 mM, and from 0.19 to 1.56 mM, respectively, when the previous degree of proteolysis (pre-hydrolysis) changed from 20 to 2%.