title: Effect of various pH values, ionic strength, and temperature on papain hydrolysis of salivary film.
abstract: Stimulated human whole saliva (WS) was used to study the dynamics of papain hydrolysis at defined pH, ionic strength, and temperature with the view of reducing an acquired pellicle. A quartz crystal microbalance with dissipation (QCM-D) was used to monitor the changes in frequency caused by enzyme hydrolysis of WS films, and the hydrolytic parameters were calculated using an empirical model. The morphological and conformational changes of the salivary films before and after enzymatic hydrolysis were characterized by atomic force microscopy (AFM) imaging and grazing-angle Fourier transform infrared (GA-FTIR ) spectra, respectively. The characteristics of papain hydrolysis of WS films were pH-, ionic strength-, and temperature-dependent. The WS films were partially removed by the action of papain, resulting in thinner and smoother surfaces. The infrared data suggested that hydrolysis-induced deformation did not occur on the remnants of salivary films. The processes of papain hydrolysis of WS films can be controlled by properly regulating pH, ionic strength, and temperature.
authors.affiliation: Department of Oral Biology and Biomaterial, Xiamen Stomatological Research Institute, Fujian Medical University, Fujian, China. dentyjw@126.com
authors.forename: Jiang-Wu
authors.initials: JW
authors.lastname: Yao
authors.forename: Yin
authors.initials: Y
authors.lastname: Xiao
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
mesh_terms: D000328:Adult; D044622:Dental Pellicle / Q000033:anatomy & histology / Q000187:drug effects*; D005260:Female; D006801:Humans; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008297:Male; D018625:Microscopy, Atomic Force; D008875:Middle Aged; D009994:Osmolar Concentration; D010206:Papain / Q000494:pharmacology*; D012471:Salivary Proteins and Peptides / Q000032:analysis; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D055672:Static Electricity; D013696:Temperature; D055815:Young Adult
chemical_list: D012471:Salivary Proteins and Peptides; D010206:Papain