Prokhorov General Physics Institute of the Russian Academy of Sciences, 119991 Moscow, Russia.
Molecules. 2022 Oct 10;27(19):6752. doi: 10.3390/molecules27196752.
The influence of laser radiation of a typical surgical laser on the physicochemical properties of the Bovine Serum Albumin (BSA) protein was studied. It was established that the physicochemical characteristics of optical breakdown weakly depend on the concentration of protein molecules. At the same time, the patterns observed for an aqueous solution of BSA irradiated with a laser for different time periods were extremely similar to the classical ones. It was established that after exposure to laser radiation, the optical density of protein solutions increases. At the same time, the intensity of BSA fluorescence due to aromatic amino acid residues decreases insignificantly after exposure to laser radiation. In this case, the position of the excitation and emission maximum does not change, and the shape of the fluorescence spot on 3D maps also does not change significantly. On the Raman spectrum after exposure to laser radiation, a significant decrease in 1570 cm was observed, which indicates the degradation of -helices and, as a result, partial denaturation of BSA molecules. Partial denaturation did not significantly change the total area of protein molecules, since the refractive index of solutions did not change significantly. However, in BSA solutions, after exposure to laser radiation, the viscosity increased, and the pseudoplasticity of aqueous solutions decreased. In this case, there was no massive damage to the polypeptide chain; on the contrary, when exposed to optical breakdown, intense aggregation was observed, while aggregates with a size of 400 nm or more appeared in the solution. Thus, under the action of optical breakdown induced by laser radiation in a BSA solution, the processes of partial denaturation and aggregation prevail, aromatic amino acid residues are damaged to a lesser extent, and fragmentation of protein molecules is not observed.
研究了典型手术激光的激光辐射对牛血清白蛋白（BSA）蛋白理化性质的影响。结果表明，光学击穿的理化特性与蛋白质分子的浓度弱相关。同时，观察到的在不同时间段内用激光辐照的 BSA 水溶液的模式与经典模式极其相似。结果表明，暴露于激光辐射后，蛋白质溶液的光密度增加。同时，暴露于激光辐射后，芳香族氨基酸残基的 BSA 荧光强度几乎没有显著降低。在这种情况下，激发和发射最大值的位置不会改变，三维图谱上荧光斑点的形状也不会发生明显变化。在暴露于激光辐射后的拉曼光谱中，观察到 1570 cm 处的显著下降，这表明 -螺旋的降解，以及 BSA 分子的部分变性。部分变性并没有显著改变蛋白质分子的总区域，因为溶液的折射率没有明显变化。然而，在 BSA 溶液中，暴露于激光辐射后，粘度增加，水溶液的假塑性降低。在这种情况下，多肽链没有受到严重破坏；相反，在光学击穿时，观察到强烈的聚集，而溶液中出现了 400nm 或更大尺寸的聚集物。因此，在激光辐射诱导的光学击穿作用下，BSA 溶液中的部分变性和聚集过程占主导地位，芳香族氨基酸残基受到的损伤较小，并且没有观察到蛋白质分子的片段化。
