Ace inhibitory peptide composition derived from ginkgo protein and preparation method and application thereof

Abstract

The present disclosure provides ACE inhibitory peptide composition derived from ginkgo protein and preparation method and application thereof, belonging to the technical field of food and medicine. The ACE inhibitory peptide composition derived from ginkgo protein mainly consists of six small molecular peptides with amino acid sequences of GFDGR (SEQ ID NO. 1), NDPGR (SEQ ID NO. 2), LDQTYRP (SEQ ID NO. 3), REHETIIL (SEQ ID NO. 4), LRMPGPPSSDDY (SEQ ID NO. 5) and LRMPGPPSDDYER (SEQ ID NO. 6). The specific preparation process includes preparation of ginkgo protein, hydrolysis of ginkgo protein, enzymolysis and hydrolysis of ginkgo protein to obtain crude ACE inhibitory peptide, and separation and purification of ACE inhibitory peptide composition derived from ginkgo protein.

1 . An ACE inhibitory peptide composition derived from ginkgo protein, wherein the ACE inhibitory peptide composition mainly consists of six small peptides with amino acid sequences of GFDGR (SEQ ID NO. 1), NDPGR (SEQ ID NO. 2), LDQTYRP (SEQ ID NO. 3), REHETIIL (SEQ ID NO. 4), LRMPGPPSSDDY (SEQ ID NO. 5) and LRMPGPPSDDYER (SEQ ID NO. 6). 
     
     
         2 . A preparation method of the ACE inhibitory peptide composition derived from ginkgo protein according to  claim 1 , comprising the following steps:
 (1) preparation of defatted ginkgo nut powder   defatting ginkgo nut powder with petroleum ether to obtain the defatted ginkgo nut powder;   (2) preparation of ginkgo protein   firstly, after mixing the defatted ginkgo nut powder obtained in step (1) with water, adding NaOH solution to adjust its pH to 10.0,   then, extracting at 40-45° C., and   subsequently, after centrifugation the extract to obtain supernatant, adjusting pH of the supernatant to 4-4.5 with HCl solution, and centrifugation the supernatant after pH adjustment to obtain ginkgo protein powder;   (3) hydrolysis of ginkgo protein   firstly, preparing the ginkgo protein powder obtained in step (2) into a protein solution with a substrate concentration of 7.17%,   then, adding NaOH solution into the protein solution to adjust the pH to 7.40, and adding 5% of AS1.398 neutral protease for hydrolysis when the temperature of the reaction reaches 45.6° C.; and   after hydrolysis for 6 h, collecting supernatant after centrifugation to obtain ginkgo protein hydrolysate;   (4) ultrafiltration separation of the ginkgo protein hydrolysate   ultrafiltering and separating the ginkgo protein hydrolysate obtained in step (3) by an ultrafiltration membrane with a molecular weight cut-off of 3 kDa to obtain ultrafiltration permeate;   (5) preparation of crude ACE inhibitory peptide derived from ginkgo protein   freeze-drying the ultrafiltration permeate obtained in step (4) to obtain crude ACE inhibitory peptide derived from ginkgo protein; and   (6) preparation of ACE inhibitory peptide composition derived from ginkgo protein   separating and purifying the crude ACE inhibitory peptide derived from ginkgo protein obtained in step (5) by a SinoChrom ODS-BP C18 reversed-phase chromatographic column, eluting and separating components at the wavelength of 220 nm, and collecting a component with the strongest ACE inhibitory activity,   separating and purifying the component with the strongest ACE inhibitory activity at the wavelength of 220 nm by using an Advance Bio peptide chromatographic column, and collecting a component with the strongest ACE inhibitory activity of the above component with the strongest ACE inhibitory activity, and   purifying the component with the strongest ACE inhibitory activity of the above component with the strongest ACE inhibitory activity by using an Advance Bio peptide chromatographic column to obtain the ACE inhibitory peptide composition derived from ginkgo protein.   
     
     
         3 . The preparation method according to  claim 2 , wherein the mass-volume ratio of the ginkgo nut powder and the petroleum ether in step (1) is 1:12. 
     
     
         4 . The preparation method according to  claim 2 , wherein the concentration of the NaOH solution in step (2) is 6 mol/L, and the concentration of the HCl solution is 6 mol/L. 
     
     
         5 . The preparation method according to  claim 2 , wherein the centrifugation condition is 4000 r/min for 30 min. 
     
     
         6 . A use of the ACE inhibitory peptide composition derived from ginkgo protein according to  claim 1  in preparing medicine for preventing and treating hypertension.