中文摘要：

采用凡纳滨对虾为研究对象,分别将过敏原提取物在-3,-20和-80℃的贮存条件下反复冻融1～5次,通过测定每次冻融后的蛋白浓度,过敏原免疫原性等探讨过敏原在不同温度循环下的变化,分析冻融循环对过敏原提取物活性的影响。结果表明,虾过敏原提取物在-80、-20、-3℃冻融循环5次时,蛋白浓度分别下降33.1%、30.0%和24.2%;在-80和-20℃冻融循环4次时,主要过敏原条带发生降解,-3℃冻融循环5次,主要过敏原条带不会发生变化。在-80和-20℃冻融循环5次以及在-3℃冻融3次时,过敏活性降低;在-80和-20℃冻融5次,主要过敏原的免疫印迹条带消失,在-3℃冻融的免疫印迹条带没有变化。因此,应尽量减少过敏原蛋白冻融次数,保证贮存在-80和-20℃的过敏原冻融循环4次以内以及-3℃冻融循环2次以内,以保证实验结果的准确性。

英文摘要：

In order to study the activity of shrimp allergens in freeze-thaw cycles,Penaeus vannamei were used to extract allergen,respectively stored at-3 ℃,-20 ℃ and-80 ℃ for one to five cycles.For the purpose of exploring the best activated condition of the allergen extract,protein concentration was determined by BCA;SDS-PAGE electrophoresis was used to evaluate protein composition;indirect ELISA and Western-blotting were used to survey allergens activity.The results showed that when shrimp allergen extract was in the cycle of freezing and thawing for five cycless at-80 ℃,-20 ℃ and-3 ℃,the protein concentration decreased by 33.1%,30.0% and 24.2% respectively.The major allergen bands were degraded,when the shrimp protein extract was freezed and thawed for four cycles at-80 ℃ and-20 ℃,on the other hand the major allergen bands didn＇t change at-3 ℃ for five cycles of freezing and thawing.The allergenic activity of shrimp protein extract had reduced when freezed and thawed for five cycles at-80 ℃ and-20 ℃ and three cycles at-3 ℃.The major allergen Western-blotting bands disappeared when five cycles of freezing and thawing were advanced at-80 ℃ and-20 ℃,while the major Western-blotting bands didn＇t change at-3 ℃.Therefore,when the allergens protein was storaged,the cycles of freeze-thawing should be reduced to ensure the allergenic activity of shrimp didn＇t change,then at-80 ℃ and-20 ℃ within four freeze-thaw cycles and at-3 ℃ less than two freeze-thaw cycles were allowed.