School of Chemical Sciences, Universiti Sains Malaysia, Penang, Malaysia.
PLoS One. 2012;7(7):e41422. doi: 10.1371/journal.pone.0041422. Epub 2012 Jul 27.
Chemical synthesis of Ag-NPs was carried out using reduction method. The reduction mechanistic approach of silver ions was found to be a basic clue for the formation of the Ag-NPs. The nanoparticles were characterized by UV-vis, FT-IR and TEM analysis. We had designed some experiments in support of our hypothesis, "low concentrations of novel nanoparticles (silver and gold) increases the activity of plant peroxidases and alter their structure also", we had used Ag-NPs and HRP as models. The immobilization/interaction experiment had demonstrated the specific concentration range of the Ag-NPs and within this range, an increase in HRP activity was reported. At 0.08 mM concentration of Ag-NPs, 50% increase in the activity yield was found. The U.V-vis spectra had demonstrated the increase in the absorbance of HRP within the reported concentration range (0.06-0.12 mM). Above and below this concentration range there was a decrease in the activity of HRP. The results that we had found from the fluorescence spectra were also in favor of our hypothesis. There was a maximum increase in ellipticity and α-helix contents in the presence of 0.08 mM concentration of Ag-NPs, demonstrated by circular dichroism (CD) spectra. Finally, incubation of a plant peroxidase, HRP with Ag-NPs, within the reported concentration range not only enhances the activity but also alter the structure.
采用还原法进行 Ag-NPs 的化学合成。银离子的还原机制方法被认为是形成 Ag-NPs 的基本线索。通过 UV-vis、FT-IR 和 TEM 分析对纳米粒子进行了表征。我们设计了一些实验来支持我们的假设，“新型纳米粒子（银和金）的低浓度会增加植物过氧化物酶的活性并改变其结构”，我们使用了 Ag-NPs 和 HRP 作为模型。固定化/相互作用实验证明了 Ag-NPs 的特定浓度范围，在这个范围内，报告了 HRP 活性的增加。在 0.08mM 的 Ag-NPs 浓度下，发现 HRP 活性的增加了 50%。U.V-vis 光谱表明，在报告的浓度范围内（0.06-0.12mM），HRP 的吸光度增加。在这个浓度范围以上和以下，HRP 的活性都下降了。我们从荧光光谱中得到的结果也支持我们的假设。在存在 0.08mM 的 Ag-NPs 浓度时，圆二色性（CD）光谱显示出最大的椭圆率和α-螺旋含量增加。最后，在报告的浓度范围内，将植物过氧化物酶 HRP 与 Ag-NPs 孵育不仅可以提高活性，还可以改变结构。
