Study On The Preparation Of Active Peptides From Meretrix Meretirx Linnaeu Protein By Enzymolysis

In this paper, active peptides were prepared from Meretrix Meretrix Linnaeu proteinhydrolysate. The antioxidant activity, ACE inhibitory activity and antiproliferative activity ofMeretrix Meretrix Linnaeu peptides were evaluated respectively. After that, activity peptideswere isolated and purified, the structure of the most potent peptide was identified.Five commercial enzymes, Protamex, Neutrase，Papain，Alcalase2.4L and Flavorzymewere used to hydrolyse Meretrix Meretrix Linnaeu protein. The degree of hydrolysis wasregarded as evaluative index. Based on the single enzyme and orthogonal tests, The optimalhydrolytic conditions of Meretrix Meretrix Linnaeu protein were confirmed. The optimalhydrolysis conditions of Protamex:45℃，pH7.0，enzymes dosage3600U/g. The optimalhydrolysis conditions of Neutrase:45℃，pH7.0，enzymes dosage1400U/g. The optimalhydrolysis conditions of Papain:50℃，pH6.5，enzymes dosage4000U/g.The optimalhydrolysis conditions of Alcalase2.4L:50℃，pH9.0，enzymes dosage2600U/g. The optimalhydrolysis conditions of Flavorzyme:50℃，pH7.5，enzymes dosage2000U/g.Antioxidant activity,ACE inhibotry activity and antiproliferative activity on two cancer cellline(Murine sarcoma S-180and human breast cancer cell line Bcap-37) were chosed to assessthe hydrolysates of five enzymes on different hydrolysis time.Through those tests,find out thebest enzyme for getting biological activity peptides and confirm their hydrolysis conditions.Theantiproliferative activity of five enzymes hydrolysates was not very well,but they showed wellon the antioxidant activity and ACE inhibitory activity. The hydrolysates scavenging activityofDPPH radical on the concentration of1.0mg/mL as follows: Protamex19.65%, Neutrase20.28%,Papain55.74%, Alcalase2.4L25.09%, Flavorzyme21.95%.ACE inhibitory activity aspects,thehydrolysates inhibitory rate of ACE on the concentration of2.0mg/mL asfollows:Protamex42.33%, Neutrase41.8%, Papain50.22%, Alcalase2.4L64.01%, Flavorzyme35.92%.Ultrafiltration, Sephadex G-25gel column chromatography and the RP-HPLC technologieswere used to purification the hysrolysates of Papain. DPPH radical scavenging rate was chose astesting index.As a result,we got a antioxidative fraction, and its structure was identified, fourpeptides and there amino acid sequence were identified: LNFNLEKSR (1120.3Da), SWLRPR(814.4Da), RIGNIISQY (1063.3Da) and LNFNLEK(877.2Da).