^(60)Coγ射线辐照剂量对牛血清白蛋白结构的影响  

Effect of ^(60)Coγ Rays Irradiation Dose on Bovine Serum Albumin Structure

作　　者：耿胜荣[1] 李新[1] 李查德[2] 鉏晓艳[1] 廖涛[1] 夏和舟[1] 叶丽秀[1] 程薇[1] 

机构地区：[1]湖北省农业科学院农产品加工与核农技术研究所/湖北省农产品辐照加工中心,武汉430064 [2]武汉理工大学化学化工与生命科学学院,武汉430070

出　　处：《湖北农业科学》2015年第21期5378-5382,共5页Hubei Agricultural Sciences

基　　金：湖北省农业科学院青年科学基金项目(2014NKYJJ23);国家自然科学基金项目(11105048);湖北省农业科技创新中心项目

摘　　要：为研究^(60)Coγ射线辐照剂量对牛血清蛋白结构的影响,以单一组分牛血清白蛋白(BSA)为模型,研究BSA水溶液辐照0~50 k Gy剂量后的含量、结构和微观形态变化。结果表明,BSA主要由25~214 k Da约10种分子量的蛋白质组成,其中55 k Da的蛋白质含量最大,各组分含量随辐照剂量的增加而下降,辐照50 k Gy时几乎全部降解;BSA在210、280 nm处各有1个紫外吸收峰,峰高均随着剂量的增加而下降,辐照30 k Gy时280 nm处的峰消失;BSA二级结构中α-螺旋、β-折叠和β-转角、无规卷曲含量分别为40.8%、37.3%和21.9%,α-螺旋含量随辐照剂量增加而下降,其他结构含量呈上升趋势;辐照前后BSA的酰胺Ⅰ带红外吸收峰从1 650.8 cm-1红移至1 655.5 cm-1处;BSA辐照后微观表面由平滑变为褶皱,形成松散的片状。辐照后牛血清白蛋白二级结构发生变化,辐照剂量越大,反应程度越大。To study the influence of 60Co γ ray irradiation dose on bovine serum component,as a single component model,BSA solution was irradiated by 0～50 kGy respectively and the protein content,secondary structure molecular and morphology were determined. The results showed that the BSA was mainly composed of 10 proteins and the molecular weights were 25～214 kDa,of which the protein content of 55 kDa was the largest one. The protein content was decreased with the increasing of irradiation dose and the content of 10 proteins were degraded after irradiated 50 kGy. The UV-Vis （UV -Visible Spectrophotometer） of BSA appeared two absorption peaks at 210 nm and 280 nm,respectively. The height of two peaks were decreased with the dose increasing and 1 280 nm-peak disappeared after the BSA was irradiated by 30 kGy. The secondary structure content of α-helix,β-fold ＆amp; β-corner and random coil from BSA were 40.8%,37.3% and 21.9%. The α-helix content decreased with the dose increasing and the other structural content increased with the dose increading. Amide I band of infrared absorption peak of bovine serum albumin shifted from 1 650.8 cm-1 to 1 655.5 cm-1. The BSA had a smooth surface microstructure before irradiation and changed into a loose sheet after irradiaton. Thus,the main effect region of the radical irradiation was α-helix of BSA,subsequently led the increasing of β-fold,β-turn and random coil increases,finally the protein turned from the ordered state into a disordered state,the greater the dose,the greater the degree of reaction.

关 键 词：60Coγ射线 牛血清白蛋白 剂量 结构改变 

分 类 号：TS201.6[轻工技术与工程—食品科学] TL99[轻工技术与工程—食品科学与工程]