Dear Debajyoti

There is also the sulfenic acid species (-S-OH) which is actually the first oxidized form of sulfhydryls on the way to sulfonic acid.  However sulfenic acids are very susceptible to further oxidation to sulfinic and sulphonic acids, and therefore need a protective chemical environment to remain stable.

See for example some previous work of ours on sulfenic and sulfinic forms of active-site cysteines in glutathione reductase (Nature Structure Biology vol 5, 267-271, 1998) and the corrresponding pdb entries 1dnc and 1gsn.

Best regards

Savvas

 

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Savvas Savvides
L-ProBE, Unit for Structural Biology
Ghent University
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http://www.lprobe.ugent.be/xray.html

 

 

 

 

Dear Sir,

Is there any other oxidation states of cysteine other than cysteine sulphinic acid and cysteine sulphonic acid. In my protein, the cysteine molecule is definitely overoxidized but the electron density is not corresponding to the sulphinic or the sulphonic acid. The positive density looks as if it can accomodate only one oxygen atom and not more.

Thank you for reply in advance.

Sincerely
Debajyoti Dutta