imidazole in radioiodinations?

[Nick Theodorakis]

On Sep 18, 4:55 pm, WS <novalidaddr... from nurfuerspam.de> wrote:
> Dear experts,
>
> we want to (radio)iodinate by the chloroamine-T method a protein which
> has been eluted from a metal affinity column with imidazol (present at
> about 0.5M). Is there the chance that it will scavenge the iodine or
> at least reduce the labeling efficiency severely?
>

Chloramine T can be used to label histidine residues, at least under
some conditions (see, e.g.,  J Biol Chem. 1982 Mar 25;257(6):2762-9),
and even Iodogen can label histine when the pH is over 9.5, according
to the Pierce literature that comes with it, so I would be wary of
including imidazole in the reaction.

Nick

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