▎ 摘　　要

NOVELTY - Preparing active peptide of aquatic product involves using pepsin enzymolysis ultra-high pressure processed bighead carp meat to obtain crude polypeptide. The crude polypeptide is separated, purified, and peptide segment tyrosine-leucine-arginine-leucine-histidine-phenylalanine (YLRLHF) is screened out after identifying. The method specifically involves obtaining crude polypeptide by processing 300MPa ultra-high pressure bighead carp meat for 20 minutes and obtaining ultra-high pressure processed bighead carp meat. The mass ratio of water to bighead carp meat is 1:5, and subjected to ultra-high pressure treatment, then added with 4000 μg pepsin, allowed to react for 6 hours at 55℃ water bath, heated for 10 minutes in the water bath at 95℃ to stop the reaction, and centrifuged to obtain hydrolysis product. USE - Method for preparing active peptide of aquatic product for reducing blood pressure. ADVANTAGE - The active peptide of aquatic product obtained has good inhibiting effect to angiotensin converting enzyme (ACE) and high-efficiency. DETAILED DESCRIPTION - Preparing active peptide of aquatic product involves using pepsin enzymolysis ultra-high pressure processed bighead carp meat to obtain crude polypeptide. The crude polypeptide is separated, purified, and peptide segment tyrosine-leucine-arginine-leucine-histidine-phenylalanine (YLRLHF) is screened out after identifying. The method specifically involves obtaining crude polypeptide by processing 300MPa ultra-high pressure bighead carp meat for 20 minutes and obtaining ultra-high pressure processed bighead carp meat. The mass ratio of water to bighead carp meat is 1:5, and subjected to ultra-high pressure treatment, then added with 4000 μg pepsin, allowed to react for 6 hours at 55℃ water bath, heated for 10 minutes in the water bath at 95℃ to stop the reaction, and centrifuged to obtain hydrolysis product. The supernatant is collected and dialysis bag (MD77-5M) is used for dialysis to remove salt to obtain crude polypeptide. The crude polypeptide is separated and purified using ultra-filtration cup with 5kDa cut-off ultrafiltration membrane ultrafiltration, where membrane pressure is mainained to 0.05MPa to obtain two molecular weight less than 5kDa, after freeze-drying mass spectrometric amino acid sequence is used, and 99% of the peptide segment is determined by Peptideranker software for activity score, where scoring result is more than 0.5 of the peptide segment for molecular butt joint, screening the peptide segment YLRLHF with the largest ACE potential activity according to the molecule butt joint result. The polypeptide sequence YLRLHF is synthesized by using the PepPowerTM polypeptide synthesis platform through solid phase synthesis method to obtain ACE inhibitory peptide YLRLHF. The nano-grade material is dissolved in water ultrasonic for 2 hours to obtain 0.1mg/mLof dispersion liquid. The nano-scale material is nano-scale oxide graphene (GO), carboxyl mesoporous silicon dioxide nano-particle (CarboxylMesoporous Silica Nanoparticle), polyethylene glycol-coated gold nano particles (terminal carboxyl group modified) (Gold Nanoparticle-PEG-N3, GN-P), or carboxyl functionalized ferroferric oxide (DMSA @ Fe3O4). 10 times diluted Nano material of 1-ethyl-(3-dimethylamino-propyl) carbonyl diimine hydrochloride (EDCl) and 20 times nano-grade material of N-hydroxy thiosuccinimide (NHS) is added to the dispersion, and stirred for 5 minutes. The weight ratio of the nano-grade material is 1-2:2-1, then ACE inhibitory peptide YLRLHF obtained is added, uniformly mixed, magnetically stirred for 6 hours to obtain reaction liquid. The obtained reaction liquid obtained is centrifuged, and precipitate is washed for 3 times by ultra-pure water, frozen and dried to obtain desired product.