School of Chemical Engineering and Australian Centre for NanoMedicine, The University of New South Wales, Sydney 2052, New South Wale, Australia.
Graduate School of Biomedical Engineering, The University of New South Wales, Sydney 2052, New South Wale, Australia.
J Am Chem Soc. 2022 Oct 5;144(39):17865-17875. doi: 10.1021/jacs.2c06471. Epub 2022 Sep 8.
Enhancing the enzymatic activity inside metal-organic frameworks (MOFs) is a critical challenge in chemical technology and bio-technology, which, if addressed, will broaden their scope in energy, food, environmental, and pharmaceutical industries. Here, we report a simple yet versatile and effective strategy to optimize biocatalytic activity by using MOFs to rapidly "lock" the ultrasound (US)-activated but more fragile conformation of metalloenzymes. The results demonstrate that up to 5.3-fold and 9.3-fold biocatalytic activity enhancement of the free and MOF-immobilized enzymes could be achieved compared to those without US pretreatment, respectively. Using horseradish peroxidase as a model, molecular dynamics simulation demonstrates that the improved activity of the enzyme is driven by an opened gate conformation of the heme active site, which allows more efficient substrate binding to the enzyme. The intact heme active site is confirmed by solid-state UV-vis and electron paramagnetic resonance, while the US-induced enzyme conformation change is confirmed by circular dichroism spectroscopy and Fourier-transform infrared spectroscopy. In addition, the improved activity of the biocomposites does not compromise their stability upon heating or exposure to organic solvent and a digestion cocktail. This rapid locking and immobilization strategy of the US-induced active enzyme conformation in MOFs gives rise to new possibilities for the exploitation of highly efficient biocatalysts for diverse applications.
在化学技术和生物技术中，提高金属有机骨架（MOFs）内的酶活性是一个关键挑战，如果得到解决，将拓宽它们在能源、食品、环境和制药行业的应用范围。在这里，我们报告了一种简单而通用且有效的策略，通过使用 MOFs 快速“锁定”超声（US）激活但更脆弱的金属酶构象，来优化生物催化活性。结果表明，与未经 US 预处理的酶相比，游离酶和 MOF 固定化酶的生物催化活性分别提高了 5.3 倍和 9.3 倍。以辣根过氧化物酶为例，分子动力学模拟表明，酶活性的提高是由血红素活性位点的开启门构象驱动的，这使得底物更有效地结合到酶上。固态紫外-可见和电子顺磁共振证实了血红素活性位点的完整性，而圆二色性光谱和傅里叶变换红外光谱则证实了 US 诱导的酶构象变化。此外，在加热或暴露于有机溶剂和消化混合物时，生物复合材料的活性提高并不会影响其稳定性。这种在 MOFs 中快速锁定和固定 US 诱导的活性酶构象的策略为开发用于各种应用的高效生物催化剂提供了新的可能性。
