Jacob Good question. One case I know is for a metalloprotein where the photoreduction of the metal centre is decreased significantly at 40K compared with 110K. Acta Cryst.<http://journals.iucr.org/d> (2007). D63<http://journals.iucr.org/d/contents/backissues.html>, 951-960 http://scripts.iucr.org/cgi-bin/paper?S0907444907035160
The paper offers a plausible explanation of why this effect occurs. The evidence is from x-ray spectroscopy rather than x-ray diffraction. Will the "subtle yet important changes" be seen with x-ray diffraction? Your plea for low temperature capability in conjunction with spectroscopic analysis is therefore relevant. I too would be interested in any updates on this. Regards Colin From: CCP4 bulletin board [mailto:[email protected]] On Behalf Of Keller, Jacob Sent: 04 April 2017 00:06 To: ccp4bb Subject: [ccp4bb] Helium-Temp Cryo-Cooling Dear Crystallographers, It is my recollection from a while ago that cryocooling to Helium temperatures has modest if any effects on protein structure or diffraction data quality, and I've found a couple of papers just now to that effect. Does anyone know differently? Do the b-factors even change? Further, is anyone aware of a beamline which has really low temperature capability, ideally in conjunction with spectroscopic analysis? All the best, Jacob Keller ******************************************* Jacob Pearson Keller, PhD Research Scientist HHMI Janelia Research Campus / Looger lab Phone: (571)209-4000 x3159 Email: [email protected]<mailto:[email protected]> ******************************************* -- This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail. Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message. Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom
