Re: [ccp4bb] Crystalization in low PH

2011-11-07 Thread Boaz Shaanan
of Sam Arnosti [meisam.nosr...@gmail.com] Sent: Monday, November 07, 2011 7:19 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Crystalization in low PH Hi everyone I have a protein that is extraordinarily stable at PH=3.0 or even 2.0. I want to crystallize it in the low PH and compare

Re: [ccp4bb] Crystalization in low PH

2011-11-07 Thread George M. Sheldrick
Tendamistat (1OK0) was crystallized at pH 1.3 and diffracted to 0.93A. George On Mon, Nov 07, 2011 at 05:19:29AM +, Sam Arnosti wrote: Hi everyone I have a protein that is extraordinarily stable at PH=3.0 or even 2.0. I want to crystallize it in the low PH and compare the differences

Re: [ccp4bb] Crystalization in low PH

2011-11-07 Thread Craig A. Bingman
I'm not convinced that you need a conventional buffer at pH 2 or 3. At pH 2, the hydrogen ion concentration is 10 mM. If you want to use something else, the second pKa for sulfuric acid is around 2. The first pKa for phosphoric acid is slightly higher than 2. Lactic acid has a pKa close to

Re: [ccp4bb] Crystalization in low PH

2011-11-07 Thread Enrico Stura
I have crystallized in PEG with citrate at pH 3. If you want to go lower I would suggest maleate: effective pH range pKa 25°Cbuffer 1.2-2.6 1.97 maleate (pK1) 2.2-6.53.13 citrate (pK1) Enrico. On Mon, 07

Re: [ccp4bb] Crystalization in low PH

2011-11-07 Thread Heping Zheng
I remembered that people had crystallize a series of streptavidin-2-iminobiotin structures at a low pH. If it might help, check the following PDBIDs: 2RTD 2RTE 2RTI 2RTK 2RTL Hi everyone I have a protein that is extraordinarily stable at PH=3.0 or even 2.0. I want to crystallize it in the

Re: [ccp4bb] Crystalization in low PH

2011-11-07 Thread Ed Pozharski
On Mon, 2011-11-07 at 05:19 +, Sam Arnosti wrote: Hi everyone I have a protein that is extraordinarily stable at PH=3.0 or even 2.0. I want to crystallize it in the low PH and compare the differences between the crystals in regular PH and low PH. I was wondering how people set up

Re: [ccp4bb] Crystalization in low PH

2011-11-07 Thread Gloria Borgstahl
Glutaraldehyde works best at low pH On Mon, Nov 7, 2011 at 8:40 AM, Ed Pozharski epozh...@umaryland.edu wrote: On Mon, 2011-11-07 at 05:19 +, Sam Arnosti wrote: Hi everyone I have a protein that is extraordinarily stable at PH=3.0 or even 2.0. I want to crystallize it in the  low PH and

[ccp4bb] Crystalization in low PH

2011-11-06 Thread Sam Arnosti
Hi everyone I have a protein that is extraordinarily stable at PH=3.0 or even 2.0. I want to crystallize it in the low PH and compare the differences between the crystals in regular PH and low PH. I was wondering how people set up the boxes in low PH, as usual buffers are mostly less acidic.