Cholate Conjugated Polymeric Amphiphiles as Efficient Artificial Ionophores.

A family of amphiphilic copolymers containing hydrophobic cholate pendants has been prepared by copolymerization of cholic acid-based monomer 2-(methacryloxy)-ethyl cholate (MAECA) with polyethylene glycol methyl ether methacrylate (PEGMA). The polymers differ for the content of MAECA that increases from 0 to 35%. The copolymers partition within liposomes and display potent ionophoric activity forming large pores in the membrane and allowing the leakage of small inorganic ions (H+, Na+) and of large polar organic molecules (calcein). Their activity is strictly correlated to the content of cholic acid subunits, increasing as the fraction of cholate moiety increases.

Engineered proteins for bioelectrochemistry.

It is only in the past two decades that excellent protein engineering tools have begun to meet parallel advances in materials chemistry, nanofabrication, and electronics. This is revealing scenarios from which synthetic enzymes can emerge, which were previously impossible, as well as interfaces with novel electrode materials. That means the control of the protein structure, electron transport pathway, and electrode surface can usher us into a new era of bioelectrochemistry. This article reviews the principle of electron transfer (ET) and considers how its application at the electrode, within the protein, and at a redox group is directing key advances in the understanding of protein structure to create systems that exhibit better efficiency and unique bioelectrochemistry.