Misc: in vivo CySO3?

John Hempel (hempel@psc.edu)
Wed, 27 May 1998 16:21:10 -0400

Hi all,
A colleague recently asked about the possibility that the irreversible
activation of his focus enzyme might be caused by generation of cysteine
sulfonic acid. Many indicators seemed consistent with this line of
reasoning: N-Ethyl maleimide blocks the activation, it's associated with
superoxide, and it's not reversible with DTT or other reductants.

Of course the in vitro modification with performic acid is well-known, but
I don't recall any examples of nature itself using the derivative to any
regulatory advantage. Does anyone know of examples? (I hope there isn't a
vast literature out there on this that I'm not aware of! And, for obvious
reasons, I can't be more specific about what enzyme I'm referring to here.)

Thanks!
JH
John Hempel, PhD Ph (412) 624 0161
University of Pittsburgh FAX (412) 624 4759
Department of Biological Sciences
Pittsburgh PA 15260 email: hempel@psc.edu
http://www.pitt.edu/~biology/faculty/hempel.html