Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown, South Africa.
Nanotechnology. 2012 Jan 27;23(3):035102. doi: 10.1088/0957-4484/23/3/035102. Epub 2011 Dec 16.
The ferroxidase activity of horse spleen apoferritin (HSAF) is increased by nine-fold in the presence of platinum nanoparticles. HSAF was mixed with varying concentrations of K2PtCl4 followed by a 20-fold concentration of sodium borohydride to afford Pt:HSAF nanoparticle complexes in a ratio of between 1:250 and 1:4000. Typical colour changes, from colourless or pale yellow to brown, occurred that were dependent on the amount of platinum present. These complexes were characterized by UV/vis, inductively coupled plasma optical emission spectroscopy, Fourier transform infrared, transmission electron microscopy and energy dispersive x-ray spectroscopy. Transmission electron microscopy analysis revealed that the size of nanoparticles increased as the molar ratio of platinum to HSAF increased with an average size diameter of 2-6 nm generated with HSAF:platinum molar ratios of 1:250-1:4000. Fourier transform infrared spectroscopy (FTIR) spectra showed no distinct changes in the structure of HSAF but confirmed that the nanoparticles were attached to the protein. The effect of platinum nanoparticles on the ferroxidase activity of HSAF showed a specific activity of 360 ρmol min(-1) mg(-1), (nine-fold increase over the control) at the molar ratio of HSAF:platinum nanoparticles of 1:1000.
马脾铁蛋白（HSAF）的亚铁氧化酶活性在铂纳米粒子存在下增加了九倍。将 HSAF 与不同浓度的 K2PtCl4 混合，然后用 20 倍浓度的硼氢化钠处理，以 1:250 至 1:4000 的比例获得 Pt:HSAF 纳米粒子复合物。典型的颜色变化，从无色或浅黄色变为棕色，取决于存在的铂量。这些复合物通过紫外/可见分光光度法、电感耦合等离子体发射光谱法、傅里叶变换红外光谱法、透射电子显微镜和能量色散 X 射线光谱法进行了表征。透射电子显微镜分析表明，随着 HSAF 与铂的摩尔比增加，纳米粒子的尺寸增大，当 HSAF 与铂的摩尔比为 1:250-1:4000 时，纳米粒子的平均直径为 2-6nm。傅里叶变换红外光谱（FTIR）谱图显示 HSAF 结构没有明显变化，但证实了纳米粒子附着在蛋白质上。铂纳米粒子对 HSAF 亚铁氧化酶活性的影响表明，在 HSAF:铂纳米粒子摩尔比为 1:1000 时，其比活性为 360 ρmol min(-1) mg(-1)（比对照增加了九倍）。
