If it is a heme or ironsulfur cluster then the reduced and oxidized forms have
distinctly different spectra. Take a spectrum of your protein reduced with a
few grains of dithionite and oxidized with a trace of hydrogen peroxide or
ferricyanide (take another spectrum of ferricyanide alone since it absorbs at
~421 nm)
eab
On 11/26/2014 11:57 AM, Guenter Fritz wrote:
Hi Monica,
what is the reducing agent the protein gets the electron from?
Or is it simply unspecific oxidation of protein side chains?
Do you know what are the coordinating residues of Fe3+ / Fe2+ ?
Dependent on the coordination Fe3+ has some (often very weak) d-d
transitions (400-500 nm) which are absent in Fe2+.
Best method of choice to check whether you have Fe3+ or Fe2+ is EPR.
Godd luck!
Guenter
I am working on a protein which binds to its ligand in a particular
state i.e. Fe3+ state (active) and reduces it to Fe2+ state
(inactive). I am trying to set up crystallisation trials with the
ligand but seems like difficult to get them. However i just needed an
advice here, is there any way to know whether the protein is in Fe2+
state or Fe3+ state or how can i make the protein to exist in more of
Fe3+ state so that i increase the probability of ligand binding to the
protein.
Your advice is highly appreciated.
Thanks in advance !!
Cheers
Monica
