Abstract
Amyloid plaque, also called senile plaque, the product of aggregation of β-amyloid peptides (Aβ), is observed in brains of the patients with Alzheimer’s disease (AD) and is one of the key factors in etiology of the disease. In this study, hydrolysates obtained from the sea hare (Aplysia kurodai) were investigated for β-secretase inhibitory peptide. The sea hare’s muscle protein was hydrolyzed using six enzymes in a batch reactor. Trypsin hydrolysate had highest β-secretase inhibitory activity compared to the other hydrolysates. β-secretase inhibitory peptide was separated using Sephadex G-25 column chromatography and high-performance liquid chromatography on a C18 column. β-secretase inhibitory peptide was identified as eight amino acid residues of Val-Ala-Ala-Leu-Met-Leu-Phe-Asn by N-terminal amino acid sequence analysis. IC50 value of purified β-secretase inhibitory peptide was 74.25 μM, and Lineweaver−Burk plots suggested that the peptide purified from sea hare muscle protein acts as a competitive inhibitor against β-secretase. Results of this study suggest that peptides derived from sea hare muscle may be beneficial as anti-dementia compounds in functional foods or as pharmaceuticals.
Highlights
Rapid economic development achieved in the elderly population increases due to the aging society
Much of Alzheimer’s disease (AD) research has been focused on the amyloid cascade hypothesis that states that β-amyloid peptide (Aβ), a proteolytic
Excessive levels of Aβ in the brain are closely related to AD pathogenesis, and much research has been focused on developing drugs that can inhibit β-secretase and thereby reduce Aβ levels, for therapeutic treatment of AD (Citron 2002)
Summary
Rapid economic development achieved in the elderly population increases due to the aging society. As the elderly population grows, the problem is an increase in patients with Alzheimer’s disease (AD). Much of AD research has been focused on the amyloid cascade hypothesis that states that β-amyloid peptide (Aβ), a proteolytic β-secretase is an aspartic protease known as BACE1 (the β-site APP-cleaving enzyme). This enzyme cleaves an accessible site at the luminal side of β-APP, and its activity is the rate-limiting step in Aβ peptide production in vivo (Vassar et al 1999).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
