Re: [ccp4bb] metals disapear

2014-05-02 Thread Dean Derbyshire
y.hell...@uit.no> Phone: +47 77646474 From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Dean Derbyshire Sent: 30. april 2014 12:33 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] metals disapear Hi all, Has anyone experienced catalytic metal ions disappearing during data collect

Re: [ccp4bb] metals disapear

2014-05-01 Thread Jrh
Dear Dean, I appreciate you might not be able to reveal further details but 'disappearing >>during<< data collection' sounds interesting as does 'metals' plural (are they expected to be close together?). Best wishes, John Prof John R Helliwell DSc On 30 Apr 2014, at 11:33, Dean Derbyshire

Re: [ccp4bb] metals disapear - sidetrack - helical scans

2014-05-01 Thread Andrew Leslie
emont, IL 60439 > > Tel: (630)252-0665 > Fax: (630)252-0667 > rsanishv...@anl.gov > > > ________ > From: zbys...@work.swmed.edu [zbys...@work.swmed.edu] > Sent: Wednesday, April 30, 2014 10:33 AM > To: Sanishvili, Ruslan > Cc: ccp4bb@jiscmail.a

Re: [ccp4bb] metals disapear

2014-05-01 Thread Andrew Leslie
Dear All, So there has been quite a bit of advice on minimising radiation damage, and on some of the effects of radiation damage, but unless I have missed it no-one has come up with a clear cut case where radiation damage actually resulted in the (complete ?) loss of a metal ion.

Re: [ccp4bb] metals disapear

2014-04-30 Thread Felix Frolow
M/CA@APS > X-ray Science Division, ANL > 9700 S. Cass Ave. > Lemont, IL 60439 > > Tel: (630)252-0665 > Fax: (630)252-0667 > rsanishv...@anl.gov > > > ____ > From: zbys...@work.swmed.edu [zbys...@work.swmed.edu] > Sent: Wednesd

Re: [ccp4bb] metals disapear

2014-04-30 Thread Sanishvili, Ruslan
swmed.edu] Sent: Wednesday, April 30, 2014 10:33 AM To: Sanishvili, Ruslan Cc: ccp4bb@jiscmail.ac.uk Subject: Re: [ccp4bb] metals disapear If metal ion will be sensitive to radiation depends on its redox chemistry and not its X-ray properties. For a metal to be affected by radiation dose it needs to

Re: [ccp4bb] metals disapear

2014-04-30 Thread Jrh Gmail
Dear Dean An example, albeit not a metal, can be found here:- http://journals.iucr.org/s/issues/2007/01/00/xh5011/xh5011.pdf Such specific damage has a long history:- http://www.sciencedirect.com/science/article/pii/0022024888903223 An X-ray sensitive metals centre is the Mn5Ca OEC of PS II and d

Re: [ccp4bb] metals disapear

2014-04-30 Thread Zbyszek Otwinowski
___ > From: CCP4 bulletin board [CCP4BB@jiscmail.ac.uk] on behalf of Dean > Derbyshire [dean.derbysh...@medivir.com] > Sent: Wednesday, April 30, 2014 5:33 AM > To: CCP4BB@jiscmail.ac.uk > Subject: [ccp4bb] metals disapear > > Hi all, > Has anyo

Re: [ccp4bb] metals disapear

2014-04-30 Thread Sanishvili, Ruslan
CCP4BB@jiscmail.ac.uk] on behalf of Dean Derbyshire [dean.derbysh...@medivir.com] Sent: Wednesday, April 30, 2014 5:33 AM To: CCP4BB@jiscmail.ac.uk Subject: [ccp4bb] metals disapear Hi all, Has anyone experienced catalytic metal ions disappearing during data collection ? If so, is there a way

Re: [ccp4bb] metals disapear

2014-04-30 Thread Zbyszek Otwinowski
My comments: Such observation is very uncommon for metals involved in catalysis by proteins. I have seen quite a few such structures involving Mg, Ca, Fe, Mn, Zn and most of the radiation damage was not at the catalytic metal. In case of Fe once I noticed slight shift in the position of the Fe ion

Re: [ccp4bb] metals disapear

2014-04-30 Thread Gerard Bricogne
Dear Dean (and Andrew), I am certainly no radiation damage guru, but at the RD8 Workshop in Hamburg 3 weeks ago (http://www.rd-eight.org/RD8-01/) I heard a talk by Pernille Harris about the photoreduction by X-rays of Cu(II) to Cu(I) in a Cu-insulin crystal. Tim's description couldn't b

Re: [ccp4bb] metals disapear

2014-04-30 Thread Keller, Jacob
30, 2014 6:33 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] metals disapear Hi all, Has anyone experienced catalytic metal ions disappearing during data collection ? If so, is there a way of preventing it? D. Dean Derbyshire Senior Research Scientist [cid:image001.jpg@01CF6450.2D6A0D80

Re: [ccp4bb] metals disapear

2014-04-30 Thread Andrew Leslie
Can the radiation damage gurus comment on this ? I know there is a problem with radiation damage changing the valence state of metals, but I don't remember hearing about the metal actually being lost due to radiation damage. Is this really common ? Thanks, Andrew On 30 Apr 2014, at 11:46, Tim

Re: [ccp4bb] metals disapear

2014-04-30 Thread Tim Gruene
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Dear Dean, this is probably a very common observation: X-rays produce reducing electrons and as you reduce a metal I imagine it does not like its chemical environment as much as it did highly charged. Everything you can do to avoid radiation damage s

[ccp4bb] metals disapear

2014-04-30 Thread Dean Derbyshire
Hi all, Has anyone experienced catalytic metal ions disappearing during data collection ? If so, is there a way of preventing it? D. Dean Derbyshire Senior Research Scientist [cid:image001.jpg@01CF6470.5FA976D0] Box 1086 SE-141 22 Huddinge SWEDEN Visit: Lunastigen 7 Direct: +