Chelating Surfaces for Native State Proteins Patterning: The Human Serum Albumin Case

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• 作者：Nicoletta Giamblanco ; Nunzio Tuccitto ; Gabriella Zappal脿 ; Gianfranco Sfuncia ; Antonino Licciardello ; Giovanni Marletta
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：October 21, 2015
• 年：2015
• 卷：7
• 期：41
• 页码：23353-23363
• 全文大小：619K
• ISSN：1944-8252

文摘

The paper reports a new 鈥渟oft鈥?surface functionalization strategy, based on a highly selective ion metal chelation process. The proposed stepwise methodology implies at first the construction of a monolayer of terpyridine-based thiol (Tpy), whose highly packed structuring has been followed in situ by using quartz crystal microbalance (QCM-D) measurements, showing that the monolayers consist of about 2.7 脳 10¹⁴ Tpy/cm². Then, the tridentate sites of the each Tpy moiety are employed to partially chelate divalent metal ions, providing an effective platform to anchoring proteins by completing the metal ion coordination with an available site on the protein of interest. We report the case study of the application of the process to the HSA immobilization onto various surfaces, including Tpy鈥揊e(II) and Tpy鈥揅u(II) complexes, as well as hydrophilic bare gold substrates and hydrophobic self-assembled Tpy-based monolayers. It is shown that the chelation interaction between Tpy鈥揅u(II) complexes and HSA produces the highest and most robust HSA immobilization, with an adsorbed mass at the steady state of 鈭?00 ng/cm², with respect to an average adsorption of 鈭?50 ng/cm² for the other surfaces. Furthermore, Cu(II)-chelated surfaces seem to promote a sort of protein 鈥渟oft鈥?landing, preventing the ubiquitous surface-induced major unfolding and transmitting an orientation information to the protein, owing to the highly specific symmetry coordination of the Tpy鈥揅u(II)鈥損rotein complex. Indeed, the interaction with a specific monoclonal antiboby (anti-HSA) indicated the lack of a significant protein denaturation, while a massive reorientation/denaturation process was found for all the remaining surfaces, including the Tpy鈥揊e(II) complex. Finally, the metal-ion-dependent HSA immobilization selectivity has been exploited to obtain micropatterned surfaces, based on the strikingly different strength of interaction and stability observed for Fe(II) and Cu(II) complexes.