H2O2 will convert cysteine to cysteic acid. Watch out for the conversion of
Met to the sulfoxide. The specificity of peroxide is pH dependent, low pH
favors Met, high pH favors cysteine. Cystine is much less reactive to peroxide
than cysteine, but the peroxide will convert the acidic amino acids to peracids
(analogs of performic or peracetic acid) which are much more powerful oxidants.
These can be expected to oxidize the disulfides to some extent, and Trp as
well. Nothing is ever easy.
Ted
At 03:05 PM 8/23/00 -0600, Ting Wong wrote:
>To all members:
>
>When a protein is treated with low concentration of hydrogen peroxide
>(say * 1%), what is the fate of the disulfide bridge(s) and free Cys?
>
>Thanks if anybody have the answer.
>
>Ting Wong
>Biomira Inc.
Theodore W. Thannhauser, Ph.D.
Director, BioResource Center
Rm. 149 Biotechnology Building
Cornell University
Ithaca, New York 14853-2703
Phone: (607) 254-4850
FAX: (607) 254-4847
Email: tt34@cornell.edu
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