Hi Bill:
Thanks for the prompt reply. I will try purifying the protein without
mercaptoethanol.
Wataru
On 2009/05/13, at 11:42, William G. Scott wrote:
HI Wataru:
I think it makes an R-S-S-R' bond, so the disulfide will prevent the
heavy atom from binding, unless exchange is rapid.
I hope all is well.
Bill
On May 12, 2009, at 7:17 PM, Wataru Kagawa wrote:
Hi.
We are trying to prepare heavy atom derivatives of a protein in
which a surface residue was mutated to cysteine. Mass spectrometry
of the purified cysteine mutant showed an additional peak with a
molecular mass that correspond to a mercaptoethanol-bound cysteine
mutant. I am wondering whether the bound mercaptoethanol prevents
the heavy atom from binding to the cysteine residue.
Any information would be greatly appreciated.
Wataru Kagawa
