title: Mechanism and kinetics of tyrosinase inhibition by glycolic acid: a study using conventional spectroscopy methods and hydrogen/deuterium exchange coupling with mass spectrometry.
abstract: Tyrosinase is an enzyme that promotes enzymatic browning of fruits and vegetables, thereby reducing product quality. A variety of analytical tools were used to characterize the interactions between tyrosinase and a natural tyrosinase inhibitor (glycolic acid). Hydrogen/deuterium exchange coupling with mass spectrometry (HDX-MS) was used to elucidate the interaction mechanism between glycolic acid and tyrosinase. UV-visible, fluorescence and circular dichroism spectroscopy analysis indicated that glycolic acid inhibited tyrosinase activity in a mixed-type manner with an IC50of 83 ± 14 μM. The results of these techniques suggested that glycolic acid bound to tyrosinase through hydrophobic attraction, and this interaction led to a pronounced conformational change of the enzyme molecules. HDX-MS analysis showed that the activity of tyrosinase was primarily inhibited by a structural perturbation of its active site (His 263). This study provides a comprehensive understanding of the interaction between glycolic acid and tyrosinase, which could lead to new approaches to control tyrosinase activity in foods and other products.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, China. tuzc_mail@aliyun.com.
authors.forename: Da
authors.initials: D
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, China. tuzc_mail@aliyun.com and College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi 330022, China.
authors.forename: Zong-Cai
authors.initials: ZC
authors.lastname: Tu
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, China. tuzc_mail@aliyun.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi 330022, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, China. tuzc_mail@aliyun.com.
authors.forename: Na
authors.initials: N
authors.lastname: He
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA 01060, USA. mcclements@foodsci.umass.edu.
authors.forename: David Julian
authors.identifier: http://orcid.org/0000-0002-9016-1291
authors.initials: DJ
authors.lastname: McClements
mesh_terms: D000363:Agaricales / Q000201:enzymology*; D002942:Circular Dichroism; D004791:Enzyme Inhibitors / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry*; D006016:Glycolates / Q000737:chemistry*; D007700:Kinetics; D013058:Mass Spectrometry; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D006016:Glycolates; C031149:glycolic acid; D014442:Monophenol Monooxygenase