Respected Mam,

I used Cadmium at home source 1.54179Ang. For detecting the
anomalous peaks CAD and FFT was used. It has Se also. So while
refining the occupancies of Cd, Se, S and P are also refined.

Thanking you
Respectfully
Kavya


> Not sure I follow you completely.. You dont say what anom scatterer you
> expect, or what the wavelength is.
>
> 1) How did you find the anomalous peaks? If from an anomalous  difference
> Fourier there will inevitably  be noise.
> In practice when there are S to check this can be very helpful in deciding
> on noise levels. You can be pretty sure
> that SG and SD are indeed S, and if the wave length is appropriate, that
> they should show some anom. signal.
>
> One often finds the well defined S show up well. then there is a grey area
> wher they are down amongst noise but still appear. It often highlights how
> many MET are in alternate conformations..
>
> If possible I like to use these as bench marks for P. But in my experience
> the P are often even weaker - maybe the ligand is not fully occupied, or
> the P temp. factors are higher?
>
>
>
>
>
>
>
>
> On 24 April 2013 10:56, Kavyashree Manjunath <ka...@ssl.serc.iisc.in>
> wrote:
>
>> Dear users,
>>
>> After detecting the anomalous peaks in a data, Is it
>> necessary that there will be an anomalous atom in most
>> of the peaks?
>>
>> In a particular case, a low ranking peak was assigned
>> an anomalous atom because it was present in the native
>> structure, while a peak with a rank higher than this
>> one did not correspond to anomalous position in native
>> structure.
>>
>> For eg. Peak 15 in ligand bound structure corresponds to
>> the anomalous position in native structure, so anomalous
>> atom was assigned.
>> But Peak 3,4 in ligand bound structure does not correspond
>> to anomalous position in native structure but it is present
>> near the ligand which is beta and gamma Phosphates of ATP.
>> The question is whether It is ATP or AMP and 2 anomalous
>> atoms?
>>
>> Thanking you
>> Regards
>> Kavya
>>
>>
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