Activation and conformational changes of chitinase induced by ultrasound

Furong Hou; Xiaobin Ma; Lihua Fan; Danli Wang; Wenjun Wang; Tian Ding; Xingqian Ye; Donghong Liu

doi:10.1016/j.foodchem.2019.01.180

Activation and conformational changes of chitinase induced by ultrasound

Food Chem. 2019 Jul 1:285:355-362. doi: 10.1016/j.foodchem.2019.01.180. Epub 2019 Feb 6.

Authors

Furong Hou¹, Xiaobin Ma², Lihua Fan¹, Danli Wang³, Wenjun Wang⁴, Tian Ding⁵, Xingqian Ye⁶, Donghong Liu⁷

Affiliations

¹ College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.
² College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China. Electronic address: xbma@zju.edu.cn.
³ College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China. Electronic address: danliwang@zju.edu.cn.
⁴ College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China. Electronic address: wangwj@zju.edu.cn.
⁵ College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R&D Center for Food Technology and Equipment, Hangzhou 310058, China. Electronic address: tding@zju.edu.cn.
⁶ College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China; Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R&D Center for Food Technology and Equipment, Hangzhou 310058, China. Electronic address: psu@zju.edu.cn.
⁷ College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China; Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R&D Center for Food Technology and Equipment, Hangzhou 310058, China. Electronic address: dhliu@zju.edu.cn.

PMID: 30797357
DOI: 10.1016/j.foodchem.2019.01.180

Abstract

This study investigated the effect of ultrasound on chitinase activity and conformational changes. Results revealed that ultrasound activated chitinase with a maximum enhancement of 19.17% compared with the untreated chitinase. Furthermore, an increase of V_max and a decrease of K_m after sonication were obtained, illustrating that the affinity between chitinase and substrate was intensified. No obvious effect on the tolerance to most metal ions was exhibited whether sonicated or not (p > 0.05). The conformational changes of chitinase were analyzed by circular dichroism (CD), Fourier transform infrared (FTIR), Raman and fluorescence spectroscopy. Results indicated that the activation of chitinase induced by ultrasound was presumably due to the decrease of tryptophan on the chitinase surface and the increase of β-sheet and random coil in chitinase secondary conformation. In brief, ultrasound is a possible way to activate chitinase to increase its application in food industry.

Keywords: Chitinase; Conformational changes; Enzymatic kinetics; Ultrasound.

MeSH terms

Chitinases / chemistry*
Circular Dichroism
Enzyme Activation
Protein Conformation
Spectrometry, Fluorescence
Spectroscopy, Fourier Transform Infrared
Spectrum Analysis, Raman
Tryptophan / chemistry
Ultrasonics* / methods

Substances

Tryptophan
Chitinases