In Situ Observation of Chymotrypsin Catalytic Activity Change Actuated by Nonheating Low-Frequency Magnetic Field
In Situ Observation of Chymotrypsin Catalytic Activity Change Actuated by Nonheating Low-Frequency Magnetic Field
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DOI：
10.1021/acsnano.7b06439
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发表时间：
2018-04-01
期刊：
影响因子：
17.1
通讯作者：
Klyachko, Natalia L.
中科院分区：
文献类型：
--
作者：
Efremova, Maria, V;Veselov, Maxim M.;Klyachko, Natalia L.
生化过程的磁力调节是生物工程和纳米医学的一种有前途的工具。这项工作演示了两种方法来控制活性的酶，α-糜蛋白酶固定在表面上的金包被的磁铁矿磁性纳米粒子（GM-MNP）使用非加热低频磁场（LF MF）。酶反应速率的测量在暴露于磁场期间原位进行。第一种方法涉及α-胰凝乳蛋白酶-GM-MNP缀合物，其中酶在LF MF（16-410 Hz频率，88 mT通量密度）下经历机械变形和MNP的重定向。这种机械变形导致α-糜蛋白酶结构的构象变化，如通过红外光谱和分子建模所证实的，并导致酶初始活性降低63%。第二种方法涉及α-糜蛋白酶-GM-MNP/胰蛋白酶促剂-GM-MNP复合物，其中酶的活性被部分抑制。在这种情况下，MNP在电场中的重新取向导致酶-抑制剂复合物的破坏和酶活性的几乎2倍的增加。结果进一步证明了纳米级磁力致动用于远程调制生化反应的实用性。
Magnetomechanical modulation of biochemical processes is a promising instrument for bioengineering and nanomedicine. This work demonstrates two approaches to control activity of an enzyme, alpha-chymotrypsin immobilized on the surface of gold-coated magnetite magnetic nanoparticles (GM-MNPs) using a nonheating low-frequency magnetic field (LF MF). The measurement of the enzyme reaction rate was carried out in situ during exposure to the magnetic field. The first approach involves alpha-chymotrypsin-GM-MNPs conjugates, in which the enzyme undergoes mechanical deformations with the reorientation of the MNPs under LF MF (16-410 Hz frequency, 88 mT flux density). Such mechanical deformations result in conformational changes in alpha-chymotrypsin structure, as confirmed by infrared spectroscopy and molecular modeling, and lead to a 63% decrease of enzyme initial activity. The second approach involves an alpha-chymotrypsin-GM-MNPs/trypsin inhibitor-GM-MNPs complex, in which the activity of the enzyme is partially inhibited. In this case the reorientation of MNPs in the field leads to disruption of the enzyme-inhibitor complex and an almost 2-fold increase of enzyme activity. The results further demonstrate the utility of magnetomechanical actuation at the nanoscale for the remote modulation of biochemical reactions.