Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho Koganei, Tokyo 184-8588, Japan.
J Colloid Interface Sci. 2010 Mar 1;343(1):65-70. doi: 10.1016/j.jcis.2009.11.043. Epub 2009 Nov 26.
Mms6 is a dominant protein that tightly associates with the surface of bacterial magnetites in Magnetospirillum magneticum AMB-1. The protein has previously been shown to mediate the formation of uniform magnetite crystals of cubo-octahedral morphology consisting of (1 1 1) and (1 0 0) crystal faces with a narrow size distribution during chemical magnetite synthesis. In order to understand the role of this protein in chemical magnetite synthesis, magnetite formation was investigated using synthetic peptides mimicking the Mms6 protein. Particles that were synthesized in the presence of short peptides harbouring the C-terminal acidic region of Mms6 exhibited a spherical morphology with circularities of 0.70-0.90 similar to those of bacterial magnetites and particles formed in the presence of the Mms6 protein. In contrast, a rectangular morphology with circularities of 0.60-0.85 were obtained when other peptides were used for synthesis. The results indicated that the C-terminal region of the Mms6 protein has significant control over the morphology of magnetite crystals in the chemical synthetic method. This method can, therefore, be useful as an alternative method of controlling the size and morphology of magnetite crystals under ambient conditions.
Mms6 是一种主要的蛋白质，它与磁小体菌 Magnetospirillum magneticum AMB-1 表面的细菌磁铁紧密结合。该蛋白质先前已被证明在化学磁铁合成过程中，介导由（1 1 1）和（1 0 0）晶面组成的具有均匀立方八面体形态的磁铁矿晶体的形成，其具有较窄的尺寸分布。为了了解该蛋白质在化学磁铁合成中的作用，使用模拟 Mms6 蛋白的合成肽研究了磁铁矿的形成。在含有 Mms6 蛋白 C 端酸性区域短肽的存在下合成的颗粒表现出具有 0.70-0.90 圆形度的球形形态，类似于细菌磁铁矿和在 Mms6 蛋白存在下形成的颗粒。相比之下，当使用其他肽进行合成时，得到具有 0.60-0.85 圆形度的矩形形态。结果表明，Mms6 蛋白的 C 端区域对化学合成方法中磁铁矿晶体的形态具有显著的控制作用。因此，该方法可作为在环境条件下控制磁铁矿晶体的尺寸和形态的替代方法。
