Plastein反应修饰对核桃血管紧张素转化酶抑制肽活性及稳定性影响研究  

Effect of Plastein reaction modification on activity and stability of walnut angiotensinⅠconverting enzyme inhibitory peptides

作　　者：曹诗诺 陈宇 韩泽玉 侯雪莹 唐明建 王丰俊 CAO Shinuo;CHEN Yu;HAN Zeyu;HOU Xueying;TANG Mingjian;WANG Fengjun(College of Biological Sciences and Technology,Beijing Forestry University,Beijing Key Laboratory of Forestry Food Processing and Safety,Beijing 100083,China)

机构地区：[1]北京林业大学生物科学与技术学院,林业食品加工与安全北京市重点实验室,北京100083

出　　处：《食品与发酵工业》2023年第21期109-115,共7页Food and Fermentation Industries

基　　金：新疆维吾尔自治区重大科技专项项目(2022A02009-4);北京林业大学大学生创新创业训练项目(G202010022091);核桃产业国家创新联盟资助项目(NAWI)。

摘　　要：通过Plastein反应对两步酶解法制备的核桃血管紧张素转化酶(angiotensinⅠconverting enzyme,ACE)抑制肽进行修饰,研究了底物质量分数、反应温度、反应时间以及添加外源氨基酸对该反应的影响。经过Plastein反应修饰后,未添加外源氨基酸的Plastein反应产物的ACE抑制率达到最高,为90.67%。对Plastein反应产物进行稳定性研究,结果表明该产物在较低温度(0~60℃)、较低离子浓度(0~2 mol/L Na^(+))下具有较好的结构稳定性;高浓度的变性剂(尿素、十二烷基硫酸钠)会破坏其结构稳定性。采用圆二色光谱研究Plastein反应产物的结构变化,结果表明Plastein反应促进了变性肽段重新扭曲折叠,导致其α-螺旋和β-折叠的变化。X-射线衍射分析表明,31.7°和45.5°的结晶峰强度变强,更为显著的是在56.4°、66.1°、75.3°和84.1°出现新的结晶峰,原子的空间排布发生了变化,说明该反应改变了ACE抑制肽的结构,从而提高了ACE抑制肽的活性。Walnut angiotensinⅠconverting enzyme(ACE)inhibitory peptide was prepared by two-step hydrolysis and modified by Plastein reaction,and the effects of substrate concentration,reaction temperature,reaction time,and addition of exogenous amino acids on the reaction were investigated.After modification by the Plastein reaction,the highest ACE inhibition rate of 90.67%was achieved for the Plastein reaction product without the addition of exogenous amino acids.Stability studies of the Plastein reaction product showed that the product had good structure stability at lower temperatures(0-60℃)and lower ionic concentrations(0-2 mol/L NaCl solution),high concentrations of denaturant(urea,sodium dodecyl sulfate)may destabilize the product.Circular dichroism spectroscopy was used to study the structural changes of the Plastein reaction products,and the results showed that the Plastein reaction promoted the re-twisted folding of the denatured peptide segment,leading to changes in itsα-helix andβ-fold.X-ray diffraction analysis showed that the intensity of the crystalline peaks became stronger at 31.7 and 45.5,and new crystalline peaks appeared at 56.4,66.1,75.3,and 84.1,where the spatial arrangement of the atoms changed,indicating that the reaction changed the structure of the ACE inhibitory peptide,thus increasing its activity.

关 键 词：核桃 血管紧张素转化酶抑制肽 Plastein反应 血管紧张素转化酶抑制活性 稳定性 

分 类 号：TS255.1[轻工技术与工程—农产品加工及贮藏工程]