Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, East China Normal University, Shanghai 200241, China.
South China Advanced Institute for Soft Matter Science and Technology, School of Molecular Science and Engineering, South China University of Technology, Guangzhou 510640, China.
Sci Adv. 2019 Aug 21;5(8):eaaw4252. doi: 10.1126/sciadv.aaw4252. eCollection 2019 Aug.
The off-on manipulation of enzyme activity is a challenging task. We report a new strategy for reversible off-on control of enzyme activity by near-infrared light. Enzymes acting on macromolecular substrates are embedded with an ultrasmall platinum nanoparticle and decorated with thermoresponsive copolymers, which exhibit upper critical solution temperature (UCST) behavior. The polymer-enzyme nanohybrids form microscale aggregates in solution below the UCST to prevent macromolecular substrates from approaching the enzymes and thus inhibit the enzyme activity, and they disassemble above the UCST to reactivate the enzyme. Upon near-infrared irradiation, platinum nanoparticles inside the enzymes generate heat through a photothermal effect to cause phase transition of the copolymers. Therefore, we can reversibly switch off and on the activities of three enzymes acting on polysaccharide, protein, and plasmid. The enzyme activities are increased by up to 61-fold after laser irradiation. This study provides a facile and efficient method for off-on control of enzyme activity.
酶活性的开-关操纵是一项具有挑战性的任务。我们报道了一种通过近红外光对酶活性进行可逆开-关控制的新策略。作用于大分子底物的酶被嵌入超小的铂纳米颗粒，并被热响应性共聚物修饰，该共聚物表现出上临界溶液温度 (UCST) 行为。聚合物-酶纳米杂化物在低于 UCST 的溶液中形成微尺度聚集体，以阻止大分子底物接近酶，从而抑制酶活性，而在 UCST 以上时则解聚以重新激活酶。近红外辐射照射下，酶内的铂纳米颗粒通过光热效应产生热量，导致共聚物发生相变。因此，我们可以可逆地关闭和打开三种作用于多糖、蛋白质和质粒的酶的活性。激光照射后，酶活性最高可提高 61 倍。这项研究为酶活性的开-关控制提供了一种简单有效的方法。
