College of Pharmaceutical Science, Hebei University, Baoding, 071002, P. R. China.
Department of Computer Teaching, Hebei University, Baoding, 071002, P. R. China.
Small. 2023 Jun;19(26):e2301413. doi: 10.1002/smll.202301413. Epub 2023 Mar 17.
In multienzymes cascade reaction, the inter-enzyme spacing is supposed to be a factor affecting the cascade activity. Here, a simple and efficient Y-shaped DNA scaffold is assembled using two partially complementary DNA single strands on magnetic microspheres, which is used to coimmobilize glucose oxidase (GOD) and horseradish peroxidase (HRP). As a result, on poly(vinyl acetate) magnetic microspheres (PVAC), GOD/HRP-DNA@PVAC multienzyme system is obtained, which can locate GOD and HRP accurately and control the inter-enzyme distance precisely. The distance between GOD and HRP is regulated by changing the length of DNA strand. It showed that the cascade activity is significantly distance-dependent. Moreover, the inter-enzyme spacing is not the closer the better, and too short distance would generate steric hindrance between enzymes. The cascade activity reached the maximum value of 967 U mg at 13.6 nm, which is 3.5 times higher than that of free enzymes. This is ascribed to the formation of substrate channeling.
在多酶级联反应中，酶间间隔被认为是影响级联活性的一个因素。在这里，我们使用两个部分互补的 DNA 单链在磁性微球上组装了一种简单而高效的 Y 型 DNA 支架，用于共固定葡萄糖氧化酶（GOD）和辣根过氧化物酶（HRP）。结果，在聚（醋酸乙烯酯）磁性微球（PVAC）上得到了 GOD/HRP-DNA@PVAC 多酶体系，它可以准确地定位 GOD 和 HRP，并精确控制酶间的距离。通过改变 DNA 链的长度来调节 GOD 和 HRP 之间的距离。结果表明，级联活性显著依赖于距离。此外，酶间的间隔并不是越近越好，过短的距离会在酶之间产生空间位阻。级联活性在 13.6nm 时达到最大值 967Umg，是游离酶的 3.5 倍。这归因于底物通道的形成。
