title: The effect of various concentrations of papain on the properties and hydrolytic rates of β-casein layers.
abstract: Recently, much attention has been focused on the investigation of the surface biocatalysis of proteases. In this study, papain, a proteolytic enzyme was used to hydrolyze a bovine β-casein (β-CN) layer, which was monitored by a quartz crystal microbalance with dissipation (QCM-D). The changes of the β-CN layers before and after hydrolysis were characterized by atomic force microscopy (AFM) imaging, grazing angle infrared spectroscopy (GA-FTIR) spectra, and contact angle measurement. Our results demonstrated that the proteolytic reaction was enzyme concentration-dependent and started with the hydrophobic C-terminal sequence of the β-CN. The remaining β-CN layer became thinner, smoother, stiffer, and hydrophilic after hydrolysis. These results are conducive to the further understanding of the catalysis of papain on β-CN layers in liquid-solid interfaces and the promotion of biocatalytic applications.
authors.affiliation: Department of Oral Biology and Biomaterials, Xiamen Stomatological Research Institute, Fujian Medical University, Fujian, China. dentyjw@126.com
authors.forename: Jiangwu
authors.initials: J
authors.lastname: Yao
authors.forename: Changjian
authors.initials: C
authors.lastname: Lin
authors.forename: Tao
authors.initials: T
authors.lastname: Tao
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
mesh_terms: D000465:Algorithms; D002364:Caseins / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry*; D004548:Elasticity; D004798:Enzymes / Q000737:chemistry; D006868:Hydrolysis; D007700:Kinetics; D018625:Microscopy, Atomic Force; D010206:Papain / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014783:Viscosity
chemical_list: D002364:Caseins; D002614:Chelating Agents; D004798:Enzymes; D010206:Papain