高压处理诱发虾原肌球蛋白结构变化与致敏性的关系

摘要

The objective of this work was to research the relationship between the conformational changes and allergenicity of tropomyosin (TM) from the white shrimp Litopenaeus vannamei after ultra-high pressure.TM was treated under different conditions of pressure (0.1-800.0 MPa),holding time (10-40 min) and temperature (10-37 ℃) and then tested for changes in it secondary and tertiary structures and allergenicity by circular dichroism spectrum (CD),fluorospectrophotometry and indirect enzyme linked immunosorbent assay (ELISA),respetively.Results showed that both the allergenicity and tertiary structure rather than the secondary structure of TM were changed under different high pressure conditions.There was a significant correlation between the changes in the allergenicity and tertiary structure of TM under different high pressure conditions.In the pressure range tested,the number of surface-exposed hydrophobic amino acids was the lowest at 20 ℃,40 min,300 MPa while achieving minimal allergenicity (OD492 nm was 0.210 ± 0.005),and the largest number of exposed hydrophobic amino acids and the maximal allergenicity (OD492nm was 0.328 ± 0.004) were observed at 700 MPa.Therefore,the allergenicity of TM was related to its tertiary structure but not its secondary structure.%以凡纳滨对虾原肌球蛋白为原料,研究不同高压条件下引发构象的变化与致敏性的关系.采用不同高压条件(压力0.1～800.0 MPa,处理时间10～40 rmin,温度10～37℃)处理原肌球蛋白(tropomyosin,TM),用圆二色谱法检测二级结构变化,荧光光度法检测三级结构变化,间接酶联免疫吸附法检测致敏性.结果显示,超高压处理能够引发TM的致敏性和三级结构变化,而对二级结构无显著影响;高压条件下TM致敏性的变化与其三级结构的改变有显著相关性.在实验压力范围内,20℃、300 MPa处理40 min TM疏水性氨基酸暴露程度最小,且致敏性最低(OD492nm为0.210±0.005);700 MPa条件下暴露程度最高,且致敏性最高(OD492nm为0.328±0.004).因此,TM致敏性与其三级结构有关,与二级结构无关.