本研究通过多光谱技术深入探讨盐浓度(离子强度)对酸性绿9(acid green 9,AG9)和酸性蓝9(acid blue 9,AB9)与牛血清白蛋白(bovine serum albumin,BSA)之间相互作用的影响。运用德拜休克尔极限理论定量分析,计算得到真实的吉布斯自由能变化(ΔG~0_I→0)和BSA的阴离子受体腔内有效电荷(Z_B)。配体AG9/AB9所带电荷Z_C的值为负,Z_B的值为正,意味着相反电荷之间离子对的形成,即AG9/AB9的负电荷与BSA的净正电荷结合腔(位点-Ⅰ)相结合,表明BSA的局部电荷主导BSA-AG9/AB9体系的相互作用,而不是它的整体或表面电荷。随着盐浓度的增加,这两个体系的熵变逐渐由正值变为负值,且焓变逐渐增大,使ΔG~0几乎不变而发生焓熵补偿。最终其热力学参数由ΔH~0<0、ΔS~0>0(静电力)在高盐浓度下转变为ΔH0<0、ΔS0<0(非静电力),表明AG9/AB9与BSA相互作用时,它们的移动或局部运动由于主导力的转变而受阻。
【英文摘要】
Multispectral techniques were employed to detect salt concentration(i.e. ionic strength)-modulated interaction of acid green 9(AG9) and acid blue 9(AB9) with bovine serum albumin(BSA). The Debye-Hückel limiting law was applied to quantitative analysis to calculate the true Gibbs free energy change(ΔG~0 I→0) and effective charge(Z_B) in the anion receptor pocket of BSA. The sign of Z_C value for AG9/AB9 was negative and the Z_B values were positive. These results indicated the formation of ion-pair between o...
【基金】
四川省科技厅应用基础项目(2016JY0080)
【更新日期】
2018-05-07
【分类号】
O629.73
【正文快照】
引文格式:曹丽君,程正军,蒋晓慧.AG9/AB9与牛血清白蛋白相互作用的德拜休克尔极限理论分析及其焓熵补偿[J].食品科学,2018,39(7):146-152.DOI:10.7506/spkx1002-6630-201807022.http://www.spkx.net.cnCAO Lijun,CHENG Zhengjun,JIANG Xiaohui.Interaction of AG9/AB9 with BSA