Lamberg P, Hamit-Eminovski J, Toscano M D, Eicher-Lorka O, Niaura G, Arnebrant T, Shleev S, Ruzgas T
Department of Chemistry, University of Rochester, 14611 Rochester, NY, USA.
CMC Diabetes Formulation Development, Novo Nordisk, Novo Alle Bagsvaerd, 2880, Denmark.
Bioelectrochemistry. 2017 Jun;115:26-32. doi: 10.1016/j.bioelechem.2017.02.001. Epub 2017 Feb 16.
The interface between protein and material surface is of great research interest in applications varying from implants, tissue engineering to bioelectronics. Maintaining functionality of bioelements depends greatly on the immobilization process. In the present study direct electron transfer of cellobiose dehydrogenase from Humicola insolens (HiCDH), adsorbed on four different self-assembled monolayers (SAMs) formed by 5-6 chain length carbon thiols varying in terminal group structure was investigated. By using a combination of quartz crystal microbalance with dissipation, ellipsometry and electrochemistry the formation and function of the HiCDH film was studied. It was found that the presence of charged pyridinium groups was needed to successfully establish direct electron contact between the enzyme and electrode. SAMs formed from hydrophilic charged thiols achieved nearly two times higher current densities compared to hydrophobic charged thiols. Additionally, the results also indicated proportionality between HiCDH catalytic constant and water content of the enzyme film. Enzyme films on charged pyridine thiols had smaller variations in water content and viscoelastic properties than films adsorbed on the more hydrophobic thiols. This work highlights several perspectives on the underlying factors affecting performance of immobilized HiCDH.
蛋白质与材料表面之间的界面在从植入物、组织工程到生物电子学等各种应用中具有极大的研究价值。生物元件功能的维持在很大程度上取决于固定化过程。在本研究中，对来源于特异腐质霉的纤维二糖脱氢酶（HiCDH）吸附在由末端基团结构不同的5 - 6链长碳硫醇形成的四种不同自组装单分子层（SAMs）上的直接电子转移进行了研究。通过结合使用具有耗散功能的石英晶体微天平、椭圆偏振仪和电化学方法，对HiCDH膜的形成及功能进行了研究。结果发现，需要存在带电荷的吡啶鎓基团才能成功在酶与电极之间建立直接电子接触。与疏水性带电荷硫醇形成的SAMs相比，亲水性带电荷硫醇形成的SAMs实现的电流密度几乎高出两倍。此外，结果还表明HiCDH催化常数与酶膜含水量之间存在比例关系。与吸附在疏水性更强的硫醇上的膜相比，带电荷吡啶硫醇上的酶膜在含水量和粘弹性性质方面的变化更小。这项工作突出了影响固定化HiCDH性能的潜在因素的几个观点。
