射频加热对辣根过氧化物酶失活和结构的影响。

The effect of radio frequency heating on the inactivation and structure of horseradish peroxidase.

机构信息

College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China.

出版信息

Food Chem. 2023 Jan 1;398:133875. doi: 10.1016/j.foodchem.2022.133875. Epub 2022 Aug 8.

DOI:10.1016/j.foodchem.2022.133875

Abstract

The effects of radio frequency (RF) heating on horseradish peroxidase (HRP) activity and its structure were investigated in this paper. The HRP was heated to 50 °C, 70 °C and 90 °C at different electrode gaps (100, 110 and 120 mm). The relative enzyme activity was 105.33 %-113.73 % at 50 °C, 91.11 %-93.05 % at 70 °C and 47.05 %-68.17 % at 90 °C. Ultraviolet-visible, circular dichroism and fluorescence spectra were used to monitor the variation in secondary and tertiary structure. The results showed that RF heating at the electrode gaps of 120 mm contributed to more severe enzyme inactivation and conformational destruction, which can be explained by the changes in Soret band, secondary structure content and tryptophan fluorescence intensity. This study revealed that enzyme inactivation by RF heating was associated with loss of helical structure, unfolding of enzyme protein and ejection of heme group.

摘要

本文研究了射频（RF）加热对辣根过氧化物酶（HRP）活性及其结构的影响。将 HRP 在不同电极间隙（100、110 和 120mm）下加热至 50°C、70°C 和 90°C。在 50°C 时相对酶活性为 105.33%-113.73%，在 70°C 时为 91.11%-93.05%，在 90°C 时为 47.05%-68.17%。紫外-可见、圆二色性和荧光光谱用于监测二级和三级结构的变化。结果表明，电极间隙为 120mm 的 RF 加热导致更严重的酶失活和构象破坏，这可以用 Soret 带、二级结构含量和色氨酸荧光强度的变化来解释。本研究表明，RF 加热引起的酶失活与螺旋结构的丧失、酶蛋白的展开和血红素基团的排出有关。