Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, Kazan, Russia.
Department of Chemistry, Kazan Federal University, Kazan, Russia.
J Biol Inorg Chem. 2024 Sep;29(6):601-609. doi: 10.1007/s00775-024-02071-z. Epub 2024 Aug 10.
The effect of binding of divalent metal cations (Ca, Cu, Mg, Mn, Zn) on the kinetics of fibril formation of bovine α-lactalbumin at acidic conditions is considered. The kinetic parameters of the process were determined using a thioflavin T fluorescence assay. The DSC thermograms of bovine α-lactalbumin in the presence and absence of cations were recorded. The duration of the lag period correlates with the changes in the thermal stability of the molten globule of the protein in the presence of cations. The final thioflavin T fluorescence intensity after formation of the mature fibrils decreases under the influence of calcium ions which strongly bind to the monomeric protein, and increases in solutions containing copper and especially zinc. These ions seem to accelerate secondary nucleation processes and change the fibril morphology, which was confirmed by atomic force microscopy imaging.
研究了二价金属阳离子（Ca、Cu、Mg、Mn、Zn）结合对牛α-乳白蛋白在酸性条件下纤维形成动力学的影响。使用硫黄素 T 荧光法测定了该过程的动力学参数。记录了存在和不存在阳离子时牛α-乳白蛋白的 DSC 热图谱。滞后期的持续时间与存在阳离子时蛋白质无规卷曲态热稳定性的变化相关。在成熟纤维形成后，终硫黄素 T 荧光强度在钙离子的影响下降低，钙离子与单体蛋白强烈结合，而在含有铜离子、特别是锌离子的溶液中增加。这些离子似乎加速了二级成核过程，并改变了纤维形态，原子力显微镜成像证实了这一点。
