posted on 2021-12-02, 09:33authored byAlonso Gamero-Quijano, Manuel Dossot, Alain Walcarius, Micheál D. Scanlon, Grégoire Herzog
Interactions of a protein with a solid−liquid or a liquid−
liquid interface may destabilize its conformation and hence result in a loss
of biological activity. We propose here a method for the immobilization of
proteins at an electrified liquid−liquid interface. Cytochrome c (Cyt c) is
encapsulated in a silica matrix through an electrochemical process at an
electrified liquid−liquid interface. Silica condensation is triggered by the
interfacial transfer of cationic surfactant, cetyltrimethylammonium, at the
lower end of the interfacial potential window. Cyt c is then adsorbed on
the previously electrodeposited silica layer, when the interfacial potential,
Δo
wϕ, is at the positive end of the potential window. By cycling of the
potential window back and forth, silica electrodeposition and Cyt c
adsorption occur sequentially as demonstrated by in situ UV−vis
absorbance spectroscopy. After collection from the liquid−liquid interface, the Cyt c−silica matrix is characterized ex situ by
UV−vis diffuse reflectance spectroscopy, confocal Raman microscopy, and fluorescence microscopy, showing that the protein
maintained its tertiary structure during the encapsulation process. The absence of denaturation is further confirmed in situ by the
absence of electrocatalytic activity toward O2 (observed in the case of Cyt c denaturation). This method of protein encapsulation
may be used for other proteins (e.g., Fe−S cluster oxidoreductases, copper-containing reductases, pyrroloquinoline quinonecontaining enzymes, or flavoproteins) in the development of biphasic bioelectrosynthesis or bioelectrocatalysis applications.
Funding
The perceptions of senior management of a semi-state organization on affirmative action