Abstract

In the present study, ultrasound irradiation was utilized to synthesize a novel zinc metal-organic framework (MOF). Scanning electron microscopic images, exhibited homogenous morphology with a nano-sized distribution of the Zn-MOF structure as also confirmed by X-ray diffraction patterns. Following, physical immobilization of Lepidium draba peroxidase (LDP) were optimized on the Zn-MOF in phosphate buffer (50 mM, pH 6.5), ratio amount of MOF/enzyme; 7/1 after shaking for 15 min at 25 degrees C, with high protein loading of 109.9 mg/g and immobilization yield of 93.3. Immobilized enzyme (IE) exhibited more than 330 enhanced specific activity and also exhibited more than 150 specific affinity to its substrate (3,3',5,5'-tetramethylbenzidine) with respect to the free enzyme (FE). Optimum temperature of the IE was obtained at 20 degrees C while its was 25 degrees C for the FE, and thermostability of the IE augmented at temperature of 30 degrees C and 40 degrees C by the factors of 104 and 108 respectively. pH stability under neutral and basic condition and storage stability of the IE improved with respect to the FE as well as its structural stability (T-m; 73 degrees C for I-E vs. 63 degrees C for F-E). Furthermore, immobilization is accompanied with alteration on the enzyme structure as revealed by the intrinsic and extrinsic fluorescence spectra. (C) 2021 Elsevier B.V. All rights reserved.