Hi,
To me this looks like a simple redox displacement
reaction which has nothing to do with oxygen. E.g. if one puts a piece of iron
in a coppersulfate solution, the more noble copper ions take electrons from
the less noble iron and will come out of solution as a metal, while the
less noble iron will disolve as ions. The same principle is used by plating zinc
on iron to prevent rust in e.g. cars. The less noble zinc will provide electrons
to protect the more noble iron.
By choosing the right metal, one might indeed be able
to very precisely reduce redox active groups in proteins.
My 2 cents,
Herman
Take a look at http://en.wikipedia.org/wiki/Great_Oxygenation_Event
This
might suggest you may have used up the available oxygen.
If you would
like to try growing your crystals in an oxygen-free environment, we (in
Leicester) have a glove box with a Douglas Instruments Oryx 4 robot. I know
its not exactly handy for Glasgow, but ......
On 1 August 2012 13:53, RHYS GRINTER
<[log in to unmask]> wrote:
Hi All,
I'm currently working of a protein with a
ferredoxin protein with anIron-Sulphur cluster. I was harvesting some
crystals the other day and a piece of my scalpel blade broke off and ended
up in the well solution. I Sealed the well without noticing, the shard of
iron oxidised and the crystals lost most of their red
colour:
Ordinary crystals:
http://s1058.photobucket.com/albums/t401/__Rhys__/?action=view¤t=MBPR_Rodcluster2edit.png
Crystals
from Blade containing well:
http://s1058.photobucket.com/albums/t401/__Rhys__/?action=view¤t=MBPR_Bleached.png
My
explanation for this (If someone has a different one that'd be great
too)
Is that the oxidation of the metallic iron the well, created
reducing conditions in the chamber and reduced the iron-sulphur cluster
(reduced ferredoxin is much less strongly coloured).
Which got me to
thinking...Could this be applied as a technique to create reducing
conditions in protein crystallography, as the use of reducing agents isn't
always practical.
Cheers,
Rhys Grinter
PhD
Candidate
University of Glasgow