Re: [ccp4bb] OT: Covalent modification of Cys by reducing agents?

2011-04-17 Thread Bernhard Rupp (Hofkristallrat a.D.)
> I have never heard of this happening (or seen a structure where there was > density for this type of adduct) Maybe it is kind of textbook-knowledge? BMC p48 Fig 2-27 http://www.ruppweb.org/garland/gallery/Ch2/index_2.htm BR Does anyone know whether or not this is possible, and why it does

Re: [ccp4bb] OT: Covalent modification of Cys by reducing agents?

2011-04-17 Thread Artem Evdokimov
Just a quick self-correction, the P(+3) in the previous post should be P(-3) -- I type too fast :) and of course, while the final product of this reaction is P(+5) the likely salient intermediate product is in fact P(-1) in the form of R3P=O (which undergoes further interesting reactions. Artem O

Re: [ccp4bb] OT: Covalent modification of Cys by reducing agents?

2011-04-17 Thread Nian Huang
Thank you for such great explanation. Hopefully people won't consider me hijacking this thread. Nian On Sun, Apr 17, 2011 at 11:08 AM, Artem Evdokimov wrote: > TCEP relies on a completely different chemistry to achieve the same goal as > BME or DTT. > DTT/BME use S(-)>SS with redox potentials of

Re: [ccp4bb] OT: Covalent modification of Cys by reducing agents?

2011-04-17 Thread Artem Evdokimov
TCEP relies on a completely different chemistry to achieve the same goal as BME or DTT. DTT/BME use S(-)>SS with redox potentials of -0.26 to -0.33 V (at pH 7) whereasTCEP uses P(3+)->P(5+) oxidation with redox potential that's a lot higher (I don't know of a reference with a stated redox potential