Maybe I was a bit hasty- the Hb example gives only 2.4% difference;
2.0 at CuKa, if I'm interpreting the output correctly.
Maybe in the F. transform the random noise averages out and the signal
rises above.
But the Hb xtal probably diffracts really well with R-merge 3 or 4 in
the low resolution shell. This is a huge multisubunit membrane protein
complex, such as I'm happy with overall rmerge 12% and 6-8% in the low
resolution shell. But if I don't say that in the grant proposal . . .
Anyway this is all hypothetical now- the protein still needs to be expressed,
purified, crystallized.
Thanks,
eab
Jim Pflugrath wrote:
> How does that compare to something that readily works with Fe, such as horse hemoglobin on a home lab copper X-ray system with 2 Fe in 291 residues in the asymmetric unit?
>
> ________________________________________
> From: CCP4 bulletin board [[log in to unmask]] on behalf of Edward A. Berry [[log in to unmask]]
> Sent: Saturday, June 01, 2013 6:46 PM
> To: [log in to unmask]
> Subject: Re: [ccp4bb] anomalous scattering server down?
>
> That's what I wanted. Results are not promising- Bijvoet differences
> would be less than 2% at peak, and this is not lysozyme.
> Thanks, all,
> eab
>
> Mooers, Blaine H.M. (HSC) wrote:
>> Bernhard Rupp has a calculator of Bijvoet ratios:
>>
>> http://www.ruppweb.org/new_comp/anomalous_scattering.htm
>>
>>
>>
>> Blaine Mooers
>> Assistant Professor
>> Director Macromolecular Crystallography Lab
>> Member Stephenson Cancer Center
>> Department of Biochemistry and Molecular Biology
>> University of Oklahoma Health Sciences Center
>> S.L. Young Biomedical Research Center Rm. 466
>>
>> Letter address:
>> P.O. Box 26901, BRC 466
>> Oklahoma City, OK 73190
>>
>> Shipping address:
>> 975 NE 10th Street, BRC 466
>> Oklahoma City, OK 73104-5419
>>
>> office: (405) 271-8300 lab: (405) 271-8313 fax: (405) 271-3910
>>
>> e-mail: [log in to unmask]
>>
>> Faculty webpage: http://www.oumedicine.com/department-of-biochemistry-and-molecular-biology/faculty/blaine-mooers-ph-d-
>> X-ray lab webpage: http://www.oumedicine.com/department-of-biochemistry-and-molecular-biology/department-facilities/macromolecular-crystallography-laboratory
>> SAXS Links webpage: http://www.oumedicine.com/docs/default-source/ad-biochemistry-workfiles/small-angle-x-ray-scattering-links.html?sfvrsn=0
>>
>> ________________________________________
>> From: CCP4 bulletin board [[log in to unmask]] On Behalf Of Edward A. Berry [[log in to unmask]]
>> Sent: Saturday, June 01, 2013 6:09 PM
>> To: [log in to unmask]
>> Subject: Re: [ccp4bb] anomalous scattering server down?
>>
>> Hmm- looks like crosssec calculates F' and F" (and cros-section).
>> I guess you're thinking of the "x-ray edge" page on the same server.
>> Ive got local copies and graphs of that in an excel spreadsheet.
>>
>> I was thinking about the page where you enter your protein's
>> molecular weight, number and type of anomalous scatterers, and
>> it tells you how accurate your data has to be to make the
>> anomalous signal significant.
>>
>> Thanks,
>> eab
>>
>> Bosch, Juergen wrote:
>>> seems to be down sorry.
>>> you should be able to use crossec from ccp4
>>> Jürgen
>>>
>>> On Jun 1, 2013, at 6:47 PM, Edward A. Berry wrote:
>>>
>>>> Is Ethan Merritt's anomalous scattering page at:
>>>> https://urldefense.proofpoint.com/v1/url?u=http://www.bmsc.washington.edu/scatter/&k=7DHVT22D9IhC0F3WohFMBA%3D%3D%0A&r=ftLbjJYpc5s5JQz9Q6qd7uT7FxPLb4V0aIwH4RJhyZU%3D%0A&m=vriAf%2FYLAE3OBEruPk8rCrKni5F1ZSfZwaGrrX0lwuk%3D%0A&s=57fb37f57cec12f6c778c53c6bfbdd04afc795f050605681dca25305998c6af0
>>>> down or moved, or the firewall I'm behind is blocking it?
>>>>
>>>> I want to check feasibility of a native-iron MAD experiment,
>>>> and I'm not very good at math.
>>>>
>>>> thanks,
>>>> eab
>>>
>>> ......................
>>> Jürgen Bosch
>>> Johns Hopkins University
>>> Bloomberg School of Public Health
>>> Department of Biochemistry & Molecular Biology
>>> Johns Hopkins Malaria Research Institute
>>> 615 North Wolfe Street, W8708
>>> Baltimore, MD 21205
>>> Office: +1-410-614-4742
>>> Lab: +1-410-614-4894
>>> Fax: +1-410-955-2926
>>> https://urldefense.proofpoint.com/v1/url?u=http://lupo.jhsph.edu/&k=7DHVT22D9IhC0F3WohFMBA%3D%3D%0A&r=ftLbjJYpc5s5JQz9Q6qd7uT7FxPLb4V0aIwH4RJhyZU%3D%0A&m=vriAf%2FYLAE3OBEruPk8rCrKni5F1ZSfZwaGrrX0lwuk%3D%0A&s=d80576bcb5bffce1fe3f7ffe04c9ec7a4b3338c452e984d4efcbd8036ce5b83c
>>>
>>>
>>>
>>>
>
|