Discovery of soy peptides from enzymatic hydrolysis of purified β‐conglycinin with potent fatty acid synthase inhibitory activity

Abstract

Current evidence indicates that fatty acid metabolism pathway represents a potential target for obesity prevention. Inhibition of fatty acid synthase (FAS) results in decrease in food intake and body weight in animal models. In addition, FAS is over‐expressed in several tumor types; therefore, its inhibition is an important therapeutic opportunity inducing tumor cell‐specific apoptosis. The objectives were the discovery and characterization of FAS inhibitory peptides derived from purified soy β‐conglycinin. FAS inhibitory peptides were produced by enzymatic hydrolysis of pure soy β‐conglycinin (BCH) using alcalase (from Bacillus licheniformis), isolated by co‐immunoprecipitation and identified on a Q‐Tof API‐US nanoAcquity UPLC tandem ESI mass spectrometer. Inhibitory activity of BCH was assayed against purified FAS from chicken liver. Soybean BCH showed a potent FAS inhibitory activity (IC50 = 35 µM) which was higher than the positive control 4‐methylene ‐2‐ octyl‐ 5‐ oxotetrahydrofuran ‐3 ‐ carboxylic acid (IC50 = 76 µM). Three hydrophilic peptides KNPQLR, EITPEKNPQLR and RKQEEDEDEEQQRE were identified. The molecular interactions of these peptides with FAS catalytic sites were evaluated by computational molecular docking. In conclusion, soy peptides were discovered for the first time with a potent FAS inhibitory activity.Supported by European Commission (PIOF‐GA‐2008‐219860), Cargill Co.