贻贝蛋白中ACE抑制肽的制备及其构效关系研究.docx

贻贝蛋白中ACE抑制肽的制备及其构效关系研究
贻贝蛋白中ACE抑制肽的制备及其构效关系研究
摘要：具有ACE抑制作用的肽多归属于食品蛋白和发酵食品中的生物活性肽，而贻贝蛋白是一种海洋食品蛋白，其具有的蛋白质组成和独特的结构使得其成为一种潜在的获得ACE抑制肽的来源。本文通过贻贝蛋白的水解制备出ACE抑制肽，研究其构效关系以及可能的功能机理。结果表明，贻贝蛋白中存在具有ACE抑制作用的肽段，且其经水解后可以明显提高ACE抑制活性。并且，随着水解时间的增加，贻贝蛋白中的ACE抑制肽含量和抑制活性也相应增强。此外，本研究还探讨了ACE抑制肽的结构与其抑制活性之间的关系，得出了一些结论对于设计和开发更有效的ACE抑制肽或食品添加剂具有一定的参考价值。
关键词：贻贝蛋白，ACE抑制肽，水解，构效关系，功能机理
Introduction
ACE(angiotensinconvertingenzyme)isanimportantenzymeinvolvedinregulatingtherenin-angiotensin-aldosteronesystem(RAAS)whichplaysakeyroleincontrollingbloodpressureandfluidbalance(1).InhibitionofACEactivityisconsideredapromisingstrategyforthetreatmentofvariouscardiovasculardiseases,includinghypertension,heartfailure,andrenaldysfunction(2).AnumberofsyntheticACEinhibitorshavebeendevelopedandarewidelyusedinclinicalpractice.However,thesesyntheticcompoundsoftenhaveundesirablesideeffects,includingcoughandangioedema(3).Therefore,thesearchfornaturalACEinhibitorshasbecomeanimportantresearchfocusinrecentyears.
ACEinhibitorscanbederivedfromvarioussources,includingfoodproteinsandfermentedfoods(4).SeveralbioactivepeptideswithACEinhibitoryactivityhavebeenisolatedfrommilk,egg,fish,andsoybeanproteins(5-8).However,therehasbeenlimitedresearchonthepotentialofmarinefoodproteinsasasourceofACEinhibitorypeptides.
Pacificoyster(Crassostreagigas)protein,oneoftheimportantmarinefoodproteins,hasauniqueproteincompositionandstructuralcharacteristicsthatmaymakeitapotentialsourceofACEinhibitorypeptides.ThisstudyaimedtoinvestigatethepreparationofACEinhibitorypeptidesfromPacificoysterproteinandexploretheirstructure-activityrelationshipandpossiblefunctionalmechanisms.
MaterialsandMethods
Materials
Pacificoysterswerepurchasedfromalocalseafoodmarket.Allreagentswereofanalyticalgradeandpurchasedfromcommercialsources.
PreparationofPacificoysterproteinhydrolysates
PacificoysterproteinwasextractedaccordingtothemethoddescribedbyZhangetal.(9).TheproteinconcentrationwasdeterminedusingtheBradfordmethod(10).Proteinhydrolysateswerepreparedbyenzymatichydroly