Liu Can, Tan Li, Zhang Kaixin, Wang Wenyi, Ma Lanqing
Key Laboratory for Northern Urban Agriculture of Ministry of Agriculture and Rural Affairs, Beijing University of Agriculture, Beinong Road 7, Huilongguan, Changping District, Beijing 102206, PR China.
Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing University of Agriculture, Beinong Road 7, Huilongguan, Changping District, Beijing 102206, PR China.
ACS Omega. 2023 Jul 18;8(30):26906-26915. doi: 10.1021/acsomega.3c01570. eCollection 2023 Aug 1.
The use of enzymes to degrade environmental pollutants has received wide attention as an emerging green approach. Horseradish peroxidase (HRP) can efficiently catalyze the degradation of phenol in the environment; however, free HRP exhibits poor stability and temperature sensitivity and is easily deactivated, which limit its practical applications. In this study, to improve their thermal stability, HRP enzymes were immobilized on mesoporous molecular sieves (Al-MCM-41). Specifically, Al-MCM-41(W) and Al-MCM-41(H) were prepared by modifying the mesoporous molecular sieve Al-MCM-41 with glutaraldehyde and epichlorohydrin, respectively, and used as carriers to immobilize HRP on their surface, by covalent linkage, to form the immobilized enzymes HRP@Al-MCM-41(W) and HRP@Al-MCM-41(H). Notably, the maximum reaction rate of HRP@Al-MCM-41(H) was increased from 2.886 × 10 (free enzyme) to 5.896 × 10 U/min, and its half-life at 50 °C was increased from 745.17 to 1968.02 min; the thermal stability of the immobilized enzyme was also significantly improved. In addition, we elucidated the mechanism of phenol degradation by HRP, which provides a basis for the application of this enzyme to phenol degradation.
作为一种新兴的绿色方法，利用酶降解环境污染物已受到广泛关注。辣根过氧化物酶（HRP）能够高效催化环境中苯酚的降解；然而，游离的HRP稳定性较差且对温度敏感，容易失活，这限制了其实际应用。在本研究中，为提高HRP的热稳定性，将HRP酶固定在介孔分子筛（Al-MCM-41）上。具体而言，分别用戊二醛和环氧氯丙烷对介孔分子筛Al-MCM-41进行改性制备Al-MCM-41(W)和Al-MCM-41(H)，并将其作为载体，通过共价连接将HRP固定在其表面，形成固定化酶HRP@Al-MCM-41(W)和HRP@Al-MCM-41(H)。值得注意的是，HRP@Al-MCM-41(H)的最大反应速率从2.886×10（游离酶）提高到5.896×10 U/min，其在50℃下的半衰期从745.17分钟增加到1968.02分钟；固定化酶的热稳定性也显著提高。此外，我们阐明了HRP降解苯酚的机制，为该酶在苯酚降解中的应用提供了依据。
