Jan,
Crystals containing haem protein are not necessarily red, the colour
depends on the oxidation state of the haem and on the haem/protein
ratio. A FeIII haem will look yellowish, gold or brown depending on
the haem/protein ratio, while an FeII haem will look more pink or red.
Daniel
Ian Ollmann a écrit :
> On Mar 12, 2008, at 12:48 PM, Jan Schoepe wrote:
>
>> Hello everybody,
>>
>> I wonder if anybody has experience with heme (or to be more precise:
>> heme b) containing proteins which Xtals do not look red under the
>> microscope. How might the technique for crystallization (e.g. sitting
>> drop, hanging drop) influence the intensity of the color? Many thanks!
>
> If there is no metal in the heme, its color will be very different. If
> your crystallization buffer contains EDTA or other strong chelating
> agents, I imagine this might happen, though protein crystallization is
> not my area.
>
> Ian
>
>
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