Characterization of β-secretase inhibitory peptide purified from skate skin protein hydrolysate

Abstract

The objective of this study was to purify and characterize the β-secretase inhibitor from enzymatic hydrolysates of skate skin, for the development of a novel antidementia agent that may be utilized in the drug or functional food industries. β-secretase inhibitory peptide was purified from various enzymatic hydrolysates of skate skin. Among six enzymatic hydrolysates, the Neutrase hydrolysate showed the highest β-secretase inhibitory activity. Consecutive purification of the skate skin hydrolysate using Sephadex G-25 column chromatography and octadecylsilane C18 reversed phase HPLC techniques was used to isolate a potent β-secretase inhibitory peptide composed of 12 amino acids, Gln–Gly–Try–Arg–Pro–Leu–Arg–Gly–Pro–Glu–Phe–Leu (MW: 1,391 Da). The purified peptide had strong β-secretase inhibitory activity, with IC50 value of 24.26 μM, and displayed a non-competitive mode of inhibition. Among the synthesized β-secretase inhibitory peptides, the tetrapeptide Pro–Glu–Phe–Leu had the highest β-secretase inhibitory activity. The result of this study suggests that the β-secretase inhibitory peptide derived from skate skin could be potential candidates to develop nutraceuticals and pharmaceuticals.