title: Effect of ultrasound on the activity and conformation of α-amylase, papain and pepsin.
abstract: The effect of ultrasound on the activity of α-amylase, papain and pepsin was investigated and the mechanism of the effect was explored by determining their conformational changes. With the irradiation of power ultrasound, the activity of α-amylase and papain was inhibited, while the activity of pepsin was activated. According to the analysis of circular dichroism, Fourier transform infrared and fluorescence spectroscopy, the πo → π(∗) amide transitions and secondary structural components, especially β-sheet, of these three enzymes were significantly influenced by ultrasound. The tryptophan fluorescence intensity of the three enzymes was also observed to be affected by sonication. Furthermore, it was found that the pepsin molecule might gradually be resistant to prolonged ultrasonic treatment and recover from the ultrasound-induced damage to its original structure. The results suggested that the activity of α-amylase, papain and pepsin could be modified by ultrasonic treatment mainly due to the variation of their secondary and tertiary structures.
authors.affiliation: The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065, PR China; National Engineering Laboratory of Clean Technology for Leather Manufacture, Sichuan University, Chengdu 610065, PR China.
authors.forename: Zhi-Long
authors.initials: ZL
authors.lastname: Yu
authors.affiliation: The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065, PR China.
authors.forename: Wei-Cai
authors.initials: WC
authors.lastname: Zeng
authors.affiliation: The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065, PR China.
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Zhang
authors.affiliation: The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065, PR China.
authors.forename: Xue-Pin
authors.initials: XP
authors.lastname: Liao
authors.affiliation: The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065, PR China; National Engineering Laboratory of Clean Technology for Leather Manufacture, Sichuan University, Chengdu 610065, PR China. Electronic address: shibi@scu.edu.cn.
authors.forename: Bi
authors.initials: B
authors.lastname: Shi
mesh_terms: D000818:Animals; D001407:Bacillus / Q000201:enzymology; D029441:Carica / Q000201:enzymology; D006867:Hydrolases / Q000737:chemistry* / Q000378:metabolism*; D010206:Papain / Q000737:chemistry / Q000378:metabolism; D010434:Pepsin A / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D013552:Swine; D014465:Ultrasonics; D000516:alpha-Amylases / Q000737:chemistry / Q000378:metabolism
chemical_list: D006867:Hydrolases; D000516:alpha-Amylases; D010206:Papain; D010434:Pepsin A
keywords: Conformation; Enzyme activity; Papain; Pepsin; Ultrasound; α-Amylase