Identification of a Novel 2S Albumin with Antitryptic Activity from Caryocar brasiliense Seeds

Proteinaceous and non-proteinaceous compounds with insecticidal activities have been isolated from plant sources. Here, protein extracts from Pequi seeds (Caryocar brasiliense) showed in vitro activity against trypsin-like enzymes. However, no activity was obtained against cancer cells, phytopathogenic fungi or human pathogenic bacteria. Further purification was performed by using trypsin-Sepharose affinity chromatography. Electrophoretic analysis revealed a single protein compound with molecular mass of approximately 14 kDa. Under reducing conditions, two peptides with smaller molecular masses were observed in SDS-PAGE, showing the presence of a heterodimeric peptide. MALDI-ToF/ToF sequencing was performed with a protein band removed from SDS-PAGE, and the sequence revealed high identity with the 2S albumin family. Purified peptide was challenged in vitro against bovine trypsin and Spodoptera frugiperda digestive enzymes by using BApNA as a substrate, showing high inhibitory activity in both cases. Data here reported suggest that a 2S albumin dimeric peptide could show biotechnological potential for S. frugiperda control. In summary, Cb2SA could be useful in controlling insect pests of agricultural interest. Â