Mimicking Nature, Scientists Can Now Extend Redox Potentials

[n2doc]

ScienceDaily (Nov. 5, 2009) — New insight into how nature handles some fundamental processes is guiding researchers in the design of tailor-made proteins for applications such as artificial photosynthetic centers, long-range electron transfers, and fuel-cell catalysts for energy conversion.

From rusting iron to forest fires to the beating of a human heart, oxidation-reduction reactions, which transfer electrons from one atom to another, are at the heart of many chemical and biological processes. Each process requires a particular redox potential, just as different electronic devices can require their own special battery.

How nature fine-tunes these potentials over a broad range with little change to the protein's electron-transfer properties or efficiency has largely remained a mystery.

Now, a team led by University of Illinois chemistry professor Yi Lu has unearthed nature's secret, and has utilized it to their advantage. The researchers describe their work in a paper to appear in the Nov. 5 issue of the journal Nature. "We show that two important interactions, hydrophobicity (water repelling) and hydrogen bonding, are capable of fine-tuning the reduction potential of a particular class of copper-containing proteins called cupredoxins," Lu said. "We extended the range both above and below what had previously been found in nature."

more:
http://www.sciencedaily.com/releases/2009/11/091104132702.htm

[eppur_se_muova]

1. Different substituents lead to different properties?

Isn't that pretty much most of modern chemistry? :shrug:

[TheMadMonk]

2. The point being made here is that only miniscule changes...

...lead to hugely varying properties. And even more usefully, "tunable" properties.

Normally redox reactions have fairly fixed properties, a potentail difference measured in volts which only varies by the specific chemistry of the reaction: lead/lead sulphate gives a PD of about, 2.4 V. Nickel/metal hydride - 1.2 V, Zinc/Amonium Chloride - 1.5 V. Lithuim/(neutral) Carbon - 3.6 V

If I'm reading this article correctly, what the boffins have managed to do is mimic/duplicate natures trick of getting a variable PD out of the same basic reaction.