Re: [ccp4bb] Crystallisation below 0°C
If your precipitant is high concentration salt, there will be a significant freezing point depression (see e.g. wikipedia entry http://en.wikipedia.org/wiki/Freezing-point_depression ). I seem to remember collecting data from crystals we cooled to -15 C in the early '80s. The crystals were grown in 2.4M Ammonium sulphate and harvested into 2.8M. Its true they were grown at room temperature but this would suggest there is no reason crystals could not be grown from high salt concentrations between 0 and whatever freezing point your precipitant solution has. Peter On 30 May 2013 15:25, Matthew Franklin wrote: > Hi Glenn - > > I have nothing systematic, but I remember that transducin-alpha (1TND) was > crystallized at -12 C, with 20% glycerol in the mother liquor. (The > crystals grew at higher temperatures, but weren't as good.) I worked on > this project briefly in grad school, and I remember that looking at the > crystals was a big nuisance - you had to take the trays out of the -12 > freezer, run to the cold room, and look at them quickly before they warmed > up too much! > > - Matt > > > > On 5/30/13 7:26 AM, Glenn Masson wrote: > > Hello CCP4BBers, > > I am currently playing with some crystals that seem to enjoy lower > temperatures, and I was thinking of breaking the 0°C threshold. > > Looking for examples of this in the literature is problematic, as > searching for examples in the PDB (Under the advanced search-> crystal > properties-> temperature (K)) turns up a large amount of false positives. > Many otherwise supremely intelligent people seem unable or unwilling to > grasp the concept of Kelvin (it's amazing how many protein structures were > solved only 22 degrees above absolute zero...). > > I was wondering if anyone has much experience in this area? I see a few > structures e.g. 2Z97 (-5°C) and 4H0W (-2°C), but I was wondering if anyone > has a more systematic knowledge, some more examples, and what the > parameters and best practice of this technique are. > > Many thanks, > > Glenn Masson > > MRC-Laboratory of Molecular Biology > > > > -- > Matthew Franklin, Ph. D. > Senior Scientist > New York Structural Biology Center > 89 Convent Avenue, New York, NY 10027(212) 939-0660 ext. 9374 > >
Re: [ccp4bb] Crystallisation below 0°C
Hi Glenn - I have nothing systematic, but I remember that transducin-alpha (1TND) was crystallized at -12 C, with 20% glycerol in the mother liquor. (The crystals grew at higher temperatures, but weren't as good.) I worked on this project briefly in grad school, and I remember that looking at the crystals was a big nuisance - you had to take the trays out of the -12 freezer, run to the cold room, and look at them quickly before they warmed up too much! - Matt On 5/30/13 7:26 AM, Glenn Masson wrote: Hello CCP4BBers, I am currently playing with some crystals that seem to enjoy lower temperatures, and I was thinking of breaking the 0°C threshold. Looking for examples of this in the literature is problematic, as searching for examples in the PDB (Under the advanced search-> crystal properties-> temperature (K)) turns up a large amount of false positives. Many otherwise supremely intelligent people seem unable or unwilling to grasp the concept of Kelvin (it's amazing how many protein structures were solved only 22 degrees above absolute zero...). I was wondering if anyone has much experience in this area? I see a few structures e.g. 2Z97 (-5°C) and 4H0W (-2°C), but I was wondering if anyone has a more systematic knowledge, some more examples, and what the parameters and best practice of this technique are. Many thanks, Glenn Masson MRC-Laboratory of Molecular Biology -- Matthew Franklin, Ph. D. Senior Scientist New York Structural Biology Center 89 Convent Avenue, New York, NY 10027 (212) 939-0660 ext. 9374
Re: [ccp4bb] Crystallisation below 0°C
If one has cryoprotectant in their conditions, one may be surprised that crystals can grow at -20 deg C and probably lower. Practice with lysosyme. :) From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Glenn Masson [glennmas...@gmail.com] Sent: Thursday, May 30, 2013 6:26 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Crystallisation below 0°C Hello CCP4BBers, I am currently playing with some crystals that seem to enjoy lower temperatures, and I was thinking of breaking the 0°C threshold. ...
Re: [ccp4bb] Crystallisation below 0°C
Glenn Masson, We had crystals that appeared by chance at "underfined" low temparature: Maïga, A., Vera, L., Marchetti, C., Lorphelin, A., Bellanger, L., Mourier, G., Servent, D., Gilles, N. & Stura, E. A. (2013) Crystallization of recombinant Green mamba ρ-Da1a toxin during lyophilization procedure and its structure determination. Acta Cryst. F 704-709. There is an intereasting zone for crystallization around zero, but the problem is going to be how to observe the crystals and accurately control the temperature. Enrico. On Thu, 30 May 2013 13:26:44 +0200, Glenn Masson wrote: Hello CCP4BBers, I am currently playing with some crystals that seem to enjoy lower temperatures, and I was thinking of breaking the 0°C threshold. Looking for examples of this in the literature is problematic, as searching for examples in the PDB (Under the advanced search-> crystal properties-> temperature (K)) turns up a large amount of false positives. Many otherwise supremely intelligent people seem unable or unwilling to grasp the concept of Kelvin (it's amazing how many protein structures were solved only 22 degrees above absolute zero...). I was wondering if anyone has much experience in this area? I see a few structures e.g. 2Z97 (-5°C) and 4H0W (-2°C), but I was wondering if anyone has a more systematic knowledge, some more examples, and what the parameters and best practice of this technique are. Many thanks, Glenn Masson> MRC-Laboratory of Molecular Biology -- Enrico A. Stura D.Phil. (Oxon) ,Tel: 33 (0)1 69 08 4302 Office Room 19, Bat.152, Tel: 33 (0)1 69 08 9449Lab http://www-dsv.cea.fr/ibitecs/simopro/ltmb/cristallogenese LTMB, SIMOPRO, IBiTec-S, CE Saclay, 91191 Gif-sur-Yvette, FRANCE http://scholar.google.com/citations?hl=en&user=Kvm06WIoPAsC&pagesize=100&sortby=pubdate http://www.chem.gla.ac.uk/protein/mirror/stura/index2.html e-mail: est...@cea.fr Fax: 33 (0)1 69 08 90 71
