Evaluation of the antioxidant activity from bovine serum albumin protein fractions

Objective:  Evaluate the antioxidant activity of protein fractions obtained from (bovine serum albumin) BSA protein hydrolysates. Design / methodology / approach: Bioinformatics tools, such as the NCBI database, were used to search for primary sequences of BSA proteins. The methodology included a prediction of peptides with antioxidant activity through various bioinformatics servers. The antioxidant activity was determined by different methods. Statistical analysis was performed to evaluate possible significant differences using the Student Newman Keulls test for group comparison. Results: Through in silica hydrolysis the following peptides were found: valine-alanine-phenylalanine (VAF), lysine-tryptophan (KW), phenylalanine-tyrosine (FY), alanine-proline (AP), among others that may have antioxidant activity. The results showed that the fraction <1 kDa hydrolyzed with chymotrypsin, this fraction showed 84% copper chelation, 61% iron chelation, while 75% inhibition of the DPPH radical. In the case of the fraction <1 kDa hydrolyzed with pepsin, it only showed 16% iron chelation, while in the other methods no value was detected. Study limitations / implications: The enzyme used for enzymatic hydrolysis generates low degrees of hydrolysis and generates oligopeptide dipeptides that may not be as like some of the tested methods, in addition to the protein concentration in the fraction <1 kDa with pepsin it had very low values that could not be detected by some antioxidant methods. Findings / conclusions: The antioxidant activity of the <1 kDa fraction obtained with chymotrypsin showed greater antioxidant and chelating activity, compared to the <1 kDa fraction obtained with pepsin. However, at the concentration of 2% and 5% fluctuations are observed in both fractions, because probably the composition of amino acids that is present in both fractions determines the activity in each of the tested method