卵转铁蛋白和乳铁蛋白的氧化稳定性的比较研究  

Comparison of ovotransferrin and lactoferrin in oxidative stability

作　　者：黎庆[1] 刘建垒[1] 景浩[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083

出　　处：《食品工业科技》2016年第5期91-97,共7页Science and Technology of Food Industry

基　　金："十二五"农村领域国家科技计划课题子课题(2012BAD28B08)

摘　　要：分析比较了卵转铁蛋白（Ovotransferrin,OVT）和乳铁蛋白（Lactoferrin,LF）的氧化稳定性。采用SDS-PAGE、蛋白溶解度、总巯基含量及羰基含量等检测方法,研究了OVT和LF在AAPH（2,2＇-azobis（2-amidinopropane）hydrochloride）作用下的结构变化,以及其对ABTS和DPPH自由基的清除率。SDS-PAGE的结果表明：当AAPH浓度为5 mmol/L时,LF在较高分子量区域开始出现新条带;当AAPH浓度为20 mmol/L时,OVT在较低分子量区域（31-43 ku）才出现新条带;随着AAPH浓度进一步增大,OVT和LF主要条带密度明显降低,经AAPH作用后出现的新条带的密度都逐渐增高。当AAPH（20 mmol/L）作用1 h时,LF即在较高分子量区域出现新条带;在4 h时,OVT才在较低分子量区域出现新条带。当OVT和LF的浓度为2 mg/m L时,AAPH（20 mmol/L）可致OVT和LF同时出现新条带;LF随其浓度增大,在较高分子量区域出现的新条带的密度逐渐降低;OVT在4 mg/m L以上时,在较低分子量区域的新长带已不可见。随着AAPH（20 mmol/L）的作用时间延长（1-8 h）,OVT和LF的溶解度、总巯基含量均逐渐下降,羰基含量均逐渐升高（p〈0.05）。OVT和LF对ABTS和DPPH自由基清除率随着蛋白浓度增大而逐渐增大（p〈0.05）。综上所述,LF较OVT更容易被AAPH氧化导致结构改变。Oxidative stability was compared between ovotransferrin （OVT） and lactoferrin （ LF）. 2, 2＇ - azobis （2-amidinopropane）hydrochloride（AAPH） was used to induce OVT and LF oxidation, and their chemical and structural changes were assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis（SDS-PAGE）, solubility, contents of total sulfhydryl and carbonyl, and free radical scavenging activity on ABTS （2,2＇- azino- bis （3-ethylbenzthiazoline-6-sulfonic acid）and DPPH （diphenyl picryl hydrazinyl radical）free radicals. Results showed that AAPH（5 mmol/L）induced new protein bands of LF at the high molecular weight area,while AAPH（20 mmol/L） induced the new protein bands of OVT at the low molecular weight area on SDS-PAGE.The density of the new protein bands of OVT and LF increased significantry with the increasing of AAPH concentrations, while the density of their original bands decreased significantly.At 20 mmol/L AAPH,the new protein bands of LF appeared at ） h, while the new protein bands of OVT appeared at 4 h.At 20 mmol/L AAPH,the new protein bands of OVT and LF appeared at 2 mg/mL, and the density of their original bands decreased significantly.The new protein bands of LF decreased gradually from 2 mg/mL to 10 mg/mL, while the new protein bands of OVT disappeared from 4 mg/mL to 10 mg/mL. When OVT and LF were incubated with AAPH（20 mmol/L） for up to 8 h,their solubility and total sulfhydryl content were gradually decreased, and carbonyl content were gradually increased. Scavenging activity of OVT and LF on ABTS and DPPH free radicals was increased with increasing OVT and LF concentrations. In conclusion, LF was oxidized by AAPH easier than OVT that led to their structural changes.

关 键 词：卵转铁蛋白 乳铁蛋白 氧化稳定性 AAPH 结构变化 

分 类 号：TS201.2[轻工技术与工程—食品科学]