Grimaldi S, Edelhoch H, Robbins J
Biochemistry. 1982 Jan 5;21(1):145-51. doi: 10.1021/bi00530a025.
The effects of thyroxine (T4) on several molecular properties of human thyroxine-binding globulin (TBG) have been evaluated. Changes in the sedimentation constant and relaxation time indicate that TBG becomes more symmetric and compact when T4 is bound. This modification in structure is associated with an increase in the stability of TBG to denaturation by either acid or guanidinium chloride. T4 binding also produces changes in the emission and excitation spectra of TBG, reflecting different environments of the four tryptophanyl residues. T4 preferentially quenches residues in a less polar environment. In addition, it alters the effect of the collisional quencher, acrylamide, so as to indicate a shift in the environment of some of the exposed tryptophanyl residues.
已评估甲状腺素（T4）对人甲状腺素结合球蛋白（TBG）若干分子特性的影响。沉降常数和弛豫时间的变化表明，当T4结合时，TBG变得更加对称和紧凑。这种结构修饰与TBG对酸或氯化胍变性的稳定性增加有关。T4结合还会使TBG的发射光谱和激发光谱发生变化，反映出四个色氨酸残基所处的不同环境。T4优先淬灭极性较小环境中的残基。此外，它改变了碰撞淬灭剂丙烯酰胺的作用，从而表明一些暴露的色氨酸残基所处环境发生了变化。
