Chen Zhengwei, Hu Fan, Lin Zaifu, Hu Jin, Shen Runqing, Lin Youhui, Liu Xiang Yang
College of Ocean and Earth Sciences Research Institution for Biomimetics and Soft Matter Fujian Key Provincial Laboratory for Soft Functional Materials Research Xiamen University 422 Siming South Road Xiamen 361005 China.
Department of Physics National University of Singapore 2 Science Drive 3 Singapore 117542 Singapore.
Small Sci. 2021 Feb 10;1(3):2000049. doi: 10.1002/smsc.202000049. eCollection 2021 Mar.
Enzymatic reactions are often terminated by severe aqueous environments. Inspired by bio-protection of silk cocoons, a system of silk fibroin (SF) nanococoons is developed, which is capable of providing a bio-protective environment for enzymatic activities on one hand, and facilitating the process of cascade enzymatic reactions on the other hand. This gives rise to the significant enhancement in enzymatic stability and efficacy. For instance, the protected glucose oxidase and horseradish peroxidase enzymes exhibit a 17.5- and 7.0-fold increase when stored at 60 °C (>50% activity; ≈28 h) and 25 °C (>67.5% activity; ≈14 days), respectively, compared with free enzymes. It follows that this protective effect is subject to the mutual templated crystallization between enzymes and SF molecules, which prevents enzyme molecules from unfolding. In animal experiments, it shows that alcohol oxidase and catalase protected by silk nanococoons are able to reduce the alcohol levels of intoxicated mice with >5.0-time efficacy at the alcohol decomposition level of >80% in 4.0 h compared with the unprotected. By bio-inspiration of silk cocoons, the silk bio-nanoreactors demonstrate the significant potential applications in biomedicine.
酶促反应常常会因恶劣的水性环境而终止。受蚕茧生物保护作用的启发，开发了一种丝素蛋白（SF）纳米茧系统，该系统一方面能够为酶活性提供生物保护环境，另一方面又能促进级联酶促反应过程。这使得酶的稳定性和功效得到显著提高。例如，与游离酶相比，受保护的葡萄糖氧化酶和辣根过氧化物酶在60°C（活性>50%；约28小时）和25°C（活性>67.5%；约14天）储存时，活性分别提高了17.5倍和7.0倍。由此可见，这种保护作用取决于酶与丝素蛋白分子之间的相互模板结晶作用，从而防止酶分子展开。在动物实验中，结果表明，与未受保护的情况相比，丝纳米茧保护的乙醇氧化酶和过氧化氢酶能够在4.0小时内将醉酒小鼠的酒精水平降低>80%，酒精分解功效提高>5.0倍。通过对蚕茧的生物启发，丝生物纳米反应器在生物医学领域展现出巨大的潜在应用价值。
