Turkish / Persian
/ Arabic / English

4  Rajab  1431 /  Thursday 17 Jun 2010 / 27 Khordad 1389 a

Tehran - 23:44 / GMT -
19:14

Mainpage

All Stories

Politics
Economy
Social
World
Culture
Foreign Policy
Nuclear
Sports
Science
Art
Defence
Photo

Search

Contact us

About
us

News number:
8903260703

12:04 | 2010-06-16

Science

Scientists Discover
'Breakwater' to Help Control Electron Transfer

TEHRAN (FNA)-
Researchers found that amino acid residues form a type
of barrier to help in the process of electron transfer
between proteins.

"This raises the bar for biomolecular
modeling," says Dennis Salahub, U of C co-author of a paper
published in the journal Proceedings of the National Academy
of Sciences (PNAS).

"At a fundamental level, it is by
far the most detailed insight that has been obtained for the
dynamic role of water in this kind of electron transfer, or
for that matter any biochemical reaction."

Electron
transfer between proteins is the cornerstone of biological
energy transfer. Every life-form uses this process to convert
food or sunlight into chemical energy.

The
interdisciplinary team of researchers found that the electron
travels over a bridge made of a water molecule, while residues
on one of the proteins form a sort of 'molecular breakwater'
to keep other water molecules away while the electron travels
across the bridge.

"You don't want too many (water
molecules around the bridge) because it gets too crowded and
they're all bumping into each other and you can't get one to
fit at just the right position and the right angle (for the
bridge) for any length of time," says PhD student and
co-author Nathan Babcock. "It's like being on a crowded subway
where you can't get comfortable."

In artificial
mutations with a faulty breakwater, the water bridge is
disrupted and the rate of electron transfer is markedly
reduced, he says.

Using the CHARMM molecular
simulation computer program, the research team examined a 40
nanosecond period of electronic coupling of the proteins
methylamine dehydrogenase and amicyanin from the bacterium
Paracoccus denitrificans.

"This is fundamental
research but you can imagine how studies like this can be
applied to various genetically modified organisms, and if you
can gain control over some, you can use it to either speed up
or slow down a particular reaction," says Salahub.

He
says the work was made possible with the collaboration of two
of the U of C's interdisciplinary research institutes; the
Institute for Biocomplexity and Informatics (IBI) and the
Institute for Quantum Information Science (IQIS).

Babcock, whose background is in quantum information
theory, was pleased to do research at the union of these two
disciplines.

"When you think of quantum mechanics,
usually you're thinking solid state semi conductors, atoms
trapped with lasers, etc. It's usually cold laboratory stuff,
not warm globby biological stuff," says the PhD student. "I
think the union of biology and quantum mechanics is very, very
exciting."

©2006 Fars News Agency. All rights
reserved