Optimization of bovine lactoferrin enzymatic hydrolysis for lactoferricin B isolation

N. URTASUN; M. V. MIRANDA; O. CASCONE; F. J. WOLMAN

San Miguel de Tucuman, Tucuman, Argentina

Congreso; SAIB 2009, 45 Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2009

SAIB

Antimicrobial peptides, particularly cationic peptides have received increasing attention as new pharmaceutical products. Bovine lactoferricin is a small positively-charged fragment of a larger protein called lactoferrin (Lf), which is found in cow’s milk and whey, a cheese manufacture subproduct. The aim of this work is to optimize the conditions for pepsin digestion of Lf in order to obtain a high yield of lactoferricin for its further purification by affinity membrane chromatography. Preliminary assays were performed in solution with standard bovine Lf. A 10 mg/ml Lf aqueous solution was adjusted to pH 1.3 or 3.0 and digested with 0.04 mg/ml porcine pepsin at 37 ºC for different periods, between 0-20 h. The reactions were stopped by heating at 80ºC for 15 min and the pH adjusted to 7.0 by addition of 1 M NaOH. Hydrolysates were tested for its antibacterial activity by using the susceptible strain Bacillus subtilis ATCC 6633. For the pH 3.0 digest, the results evidenced time dependence with the highest antimicrobial activity after 20 h incubation. For the pH 1.3 digest, the maximum antimicrobial activity appeared at 1 h and remained constant in the period studied. For Lf adsorbed onto chromatographic matrix hydrolysis, the pH 3.0-based process is the best choice attended to the chemical stability of the support.