Beijing Advanced Innovation Center for Food Nutrition and Human Health , Beijing Technology and Business University , Beijing 100048 , China.
State Key Laboratory of Food Nutrition and Safety, Ministry of Education , Tianjin University of Science and Technology , Tianjin 300457 , China.
J Agric Food Chem. 2019 Jun 12;67(23):6633-6641. doi: 10.1021/acs.jafc.9b01739. Epub 2019 Jun 3.
Ferritin is a multisubunit protein with a hollow interior interface and modifiable surfaces. In this study, the manothermosonication (MTS) technology was applied to apo-red bean seed ferritin (apoRBF) to produce the MTS-treated apoRBF (MTFS). MTS treatment (200 kPa, 50 °C, and 40 s) maintained the spherical morphology of apoRBF (12 nm), but reduced the content of α-helix structure and increased the content of random coil structure, and correspondingly decreased the ferritin stability. The MTS treatment also affected the ferritin's iron storage function by decreasing its iron oxidative deposition activity and increasing the iron release activity. Importantly, the disassembly and reassembly properties of the MTFS induced by pH changes were retained, which facilitated its usage in encapsulation of tea polyphenol-epigallocatechin gallate (EGCG) into the ferritin by a relatively benign pH conversion routine (pH 3.0/6.8). In addition, the water solubility of the MTFS was increased, leading to the improved encapsulation efficiency of the EGCG molecules. This study will facilitate the ferritin modification and functionalization by MTS to design a protein variant to be used as new scaffold for iron and bioactive compounds.
铁蛋白是一种具有中空内部界面和可修饰表面的多亚基蛋白。在本研究中，采用磁声处理（MTS）技术处理去铁蛋白红小豆种子铁蛋白（apoRBF）以制备 MTS 处理的 apoRBF（MTFS）。MTS 处理（200 kPa、50°C 和 40 s）保持了 apoRBF（12 nm）的球形形态，但降低了α-螺旋结构的含量，增加了无规卷曲结构的含量，相应地降低了铁蛋白的稳定性。MTS 处理还通过降低其铁氧化沉积活性和增加铁释放活性来影响铁蛋白的铁储存功能。重要的是，MTFS 的 pH 值变化诱导的组装和再组装特性得以保留，这有助于通过相对温和的 pH 值转换程序（pH 3.0/6.8）将茶多酚-表没食子儿茶素没食子酸酯（EGCG）封装到铁蛋白中。此外，MTFS 的水溶性增加，导致 EGCG 分子的包封效率提高。这项研究将促进 MTS 对铁蛋白的修饰和功能化，设计一种蛋白质变体，用作铁和生物活性化合物的新型支架。
