高密度CO_2对凡纳滨对虾肌球蛋白疏水性的影响

Effect of Dense Phase Carbon Dioxide on Hydrophobicity of Myosin Proteins from Litopenaeus vannamei

为揭示高密度 CO2（Dense Phase Carbon Dioxide,DPCD）诱导肌球蛋白形成凝胶的机制,利用ANS 探针法和荧光法,分别测定在压力5～30 MPa、温度50～70 ℃、时间10～50 min 等不同处理条件下肌球蛋白表面疏水性和酪氨酸内源荧光值,探讨DPCD 对凡纳滨对虾肌球蛋白高级结构的影响.研究表明：与未处理的肌球蛋白相比,DPCD 处理能使肌球蛋白的表面疏水性和酪氨酸内源荧光值显著增加（P〈0.05）;在相同温度下,DPCD 处理的肌球蛋白的表面疏水性和酪氨酸内源荧光值显著高于水浴热处理的（P〈0.05）;DPCD 处理压力、温度升高以及时间延长,均能使肌球蛋白的表面疏水性和酪氨酸内源荧光值显著增加（P〈0.05）.DPCD 能够诱导肌球蛋白疏水基团暴露,使紧密的高级结构发生松散.

This study investigated the effect ofdense phase carbon dioxide (DPCD) on myosin gel formation induced by measuring the surface hydrophobicity and tyrosine intrinsic fluorescence spectrum of myosin in different conditions (pressure 5~30 MPa, temperature 50~70℃, time 10~50 min) with ANS probe and fluorescence scanning, respectively. The results indicated that DPCD treatment increased the surface hydrophobicity and the intrinsic fluorescence value of tyrosine significantly (P<0.05). Under the same temperature, the surface hydrophobicity and the intrinsic fluorescence value of tyrosine of myosin treated by DPCD were significantly higher than those of water bath heat-treatment (P<0.05). DPCD significantly enhanced the surface hydrophobicity and the intrinsic fluorescence value of myosin tyrosine with the increased pressure and temperature and the extension of time (P<0.05). These findings showed that DPCD could expose the hydrophobic group of myosin, which could loose the tight advanced structure.