[ccp4bb] Sulphate or phosphate?

2018-07-31 Thread David Schuller
How can one distinguish between a sulphate or phosphate in an electron density map? Both are present in the mother liquor, and resolution is in the range of 1.75 - 2.25 A -- === All Things Serve the Beam ==

Re: [ccp4bb] Sulphate or phosphate?

2018-07-31 Thread Roger Rowlett
You might be able to distinguish sulfate from phosphate by examining hydrogen bonding partners. Phosphate can donate one or two hydrogen bonds at neutral pH values, whereas sulfate is usually only a hydrogen bond acceptor. (Having said that, we have published a structure where a sulfate clearly int

Re: [ccp4bb] Sulphate or phosphate?

2018-07-31 Thread Robbie Joosten
Sent: Tuesday, July 31, 2018 3:38:38 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Sulphate or phosphate? How can one distinguish between a sulphate or phosphate in an electron density map? Both are present in the mother liquor, and resolution is in the range of 1.75 - 2.25 A

Re: [ccp4bb] Sulphate or phosphate?

2018-07-31 Thread Oganesyan, Vaheh
not a mixture of both. Regards, Vaheh Oganesyan, PhD www.medimmune.com -Original Message- From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of David Schuller Sent: Tuesday, July 31, 2018 9:39 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Sulphate or phosphate? How

Re: [ccp4bb] Sulphate or phosphate?

2018-08-01 Thread armin.wag...@diamond.ac.uk
Dear David, The long-wavelength beamline I23 at Diamond (http://www.diamond.ac.uk/Instruments/Mx/I23.html) can go all way down to the phosphorous edge. While data quality will be obviously compromised by absorption effects (we are working on this), for a reasonably well diffracting crystal lik

Re: [ccp4bb] Sulphate or phosphate?

2018-08-01 Thread Eleanor Dodson
I am not sure if you gave your wave length but it is always worth doing an anomalous map, and looking at relativr peak heights for your known S positions and the putative sulphate or phosphate. There are small differences in the expected f" at most wavelengths. Chemical arguments are doubtless bet

Re: [ccp4bb] Sulphate or phosphate?

2018-08-02 Thread armin.wag...@diamond.ac.uk
bridge which should illustrate it better. Best regards, Armin [cid:image001.png@01D42A41.AE0B8B60] From: Eleanor Dodson Date: Wednesday, 1 August 2018 at 19:09 To: Armin Wagner Cc: "ccp4bb@jiscmail.ac.uk" Subject: Re: [ccp4bb] Sulphate or phosphate? I am not sure if you

[ccp4bb] FW: [ccp4bb] Sulphate or phosphate?

2018-08-02 Thread armin.wag...@diamond.ac.uk
it better. Best regards, Armin [cid:image001.png@01D42A41.AE0B8B60] From: Eleanor Dodson Date: Wednesday, 1 August 2018 at 19:09 To: Armin Wagner Cc: "ccp4bb@jiscmail.ac.uk" Subject: Re: [ccp4bb] Sulphate or phosphate?

[ccp4bb] FW: [ccp4bb] Sulphate or phosphate?

2018-08-02 Thread Charles Ballard - UKRI STFC
Begin forwarded message (on behalf of Armin Wagner) From: ahw78 mailto:armin.wag...@diamond.ac.uk>> Date: 2 August 2018 at 09:17:48 BST To: Eleanor Dodson mailto:eleanor.dod...@york.ac.uk>> Cc: ccp4bb mailto:ccp4bb@jiscmail.ac.uk>> Subject: Re: [ccp4bb] Sulphate or phosphate? Dea

Re: [ccp4bb] FW: [ccp4bb] Sulphate or phosphate?

2018-08-02 Thread Charles Ballard - UKRI STFC
ahw78 mailto:armin.wag...@diamond.ac.uk>> > Date: 2 August 2018 at 09:17:48 BST > To: Eleanor Dodson > mailto:eleanor.dod...@york.ac.uk>> > Cc: ccp4bb mailto:ccp4bb@jiscmail.ac.uk>> > Subject: Re: [ccp4bb] Sulphate or phosphate? > Dear Eleanor, > > We can tune

[ccp4bb] Fwd: [ccp4bb] Sulphate or phosphate? (Armin's figures)

2018-08-02 Thread Charles Ballard - UKRI STFC
Begin forwarded message: [cid:image001.png@01D42A41.AE0B8B60] To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1