巯基蛋白酶水解蛋白质/色素复合膜

Cysteine Proteases Hydrolysis of Protein/pigment Complex Film

目的:采用茶黄素(theaflavin,TF)和去磷酸化牛β-酪蛋白(dephosphorylated bovineβ-casein,Dβ-CN)在芯片表面形成蛋白质/色素复合膜的模型,评估3种巯基蛋白酶(cysteine proteases,CPs),木瓜蛋白酶、菠萝蛋白酶和无花果蛋白酶,对Dβ-C/TF复合膜的清除作用。方法:在消散石英晶体微天平(quartz crystal microbalance with dissipation,QCM-D)上建立Dβ-C/TF复合膜,Boltzman方程评估CPs水解复合膜的质量,水解前后膜变化通过掠角傅里叶变换红外光谱(grazing angle fourier transform infrared spectroscopy spectra,GA-FTIR)。结果:3种CPs水解复合膜的功效由大到小依次为无花果蛋白酶、木瓜蛋白酶、菠萝蛋白酶(P<0.05)。红外光谱表征结果证实,CPs能够有效地清除结合在Dβ-CN表面的TF。结论:本研究表明,CPs具有在牙色渍清除中潜在的应用价值。在开发口腔保健产品中该类酶值得进一步研究。

Objective： To employe a model of protein/pigment complex film using theaflavin （TF） and dephosphorylated bovine β-casein （Dβ-CN） on a sensor surface to assess the efficacy of three kinds of cysteine proteases （CPs） including papain, stem bromelain, and ficin on removing Dβ-CN/TF. Methods： Dβ-CN/TF complex film was built by using a quartz crystal microbalance with dissipation （QCM--D）. The masses of CPs hydrolysis of Dβ- CN/TF complex films were assessed by QCM-D. The surface details before and after hydrolysis were detected by grazing angle fourier transform infrared spectroscopy spectra （GA-FTIR）. Results： The efficacy order of CPs on hydrolyzing protein/pigment complex film is ficin 〉 papain 〉 bromelain （P〈0.05）. The results from GA-FTIR demonstrated that TF bound on the Dβ-CN was effectively removed by the CPs. Conclusion： This study indicates the potential application of the CPs for tooth stain removal and suggests that these enzymes are worthy of further investigation for use in oral healthcare.