Purification and identification of adipogenesis inhibitory peptide from black soybean protein hydrolysate

Adipogenesis inhibitory peptide was isolated and identified from black soybean (Rhynchosia volubilis Lour.) hydrolysate. An adipogenesis inhibitor was purified using consecutive methods including: ultrafiltration (MWCO; 3 and 10kDa), gel filtration chromatography (Superdex Peptide 10/300 GL column), and reverse-phase high-performance liquid chromatography (microBondapak C(18) column). Also, the adipogenesis inhibition effect of the purified peptide was measured by observation of droplet of 3T3-L1 adipocyte by Oil Red O staining in the highest active fraction in each step. The peptide was shown to inhibit the differentiation of the 3T3-L1 pre-adipocyte, which was confirmed by morphological study. The adipogenesis inhibitory peptide was purified 71.43-fold from black soybean hydrolysate throughout a five-step purification procedure. The adipogenesis inhibitor was identified to be a tripeptide, Ile-Gln-Asn, having an IC(50) value of 0.014 mg protein/ml. Furthermore, the synthetic tripeptide (Ile-Gln-Asn) exhibited the similar adipogenesis effects to the purified peptide. Thus, these results showed the potential anti-obesity effect of the purified peptide through control of adiposity.