Specific and reversible immobilization of proteins tagged to the affinity polypeptide C-LytA on functionalized graphite electrodes

We have developed a general method for the specific and reversible immobilization of proteins fused to the choline-binding module C-LytA on functionalized graphite electrodes. Graphite electrode surfaces were modified by diazonium chemistry to introduce carboxylic groups that were subsequently used to anchor mixed self-assembled monolayers consisting of N,N-diethylethylenediamine groups, acting as choline analogs, and ethanolamine groups as spacers. The ability of the prepared electrodes to specifically bind C-LytA-tagged recombinant proteins was tested with a C-LytA-β-galactosidase fusion protein. The binding, activity and stability of the immobilized protein was evaluated by electrochemically monitoring the formation of an electroactive product in the enzymatic hydrolysis of the synthetic substrate 4-aminophenyl β-D-galactopyranoside. The hybrid protein was immobilized in an specific and reversible way, while retaining the catalytic activity. Moreover, these functionalized electrodes were shown to be highly stable and reusable. The method developed here can be envisaged as a general, immobilization procedure on the protein biosensor field.

Ecos de Europa: la representación parlamentaria en el Chile liberal del siglo XIX

This paper explores the significant influences of European liberalism, and in particular French liberalism, in the Chilean thought and political culture/praxis during the construction of the State in the mid-19th century. It reveals and discusses the significant circulation of ideas that an array of Chilean travelers and exiles in several European countries generated and promoted in Chile in the middle of the 19th century. Among the intellectuals and politicians treated by this article are Andrés Bello, Manuel Antonio Tocornal, Santiago Arcos, Francisco Bilbao, Manuel Antonio Matta and Ángel Custodio Gallo.