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regaentDear All,
I am sure this question was discussed before. But I am wondering if anyone got
the same experience as I do. I got a crystal out of condition with 1M KCl, 1.4M
Ammonium sulfate at pH7. I tried to use glycerol, ethylene glycol, 25% sucrose,
paraton-N oil, or ammonium sulfate
Min,
In some of my Xtal conditions, I only have 1.5 to 2M AmSO4 without KCl, the
salt comes out of solution only after maybe several minutes which is enough to
harvest the crystal. Maybe you could just direct freeze to try the diffraction
since it is already at high salt concentration or maybe
Hi,
I have used pure malonate (above 3M) for a similar condition. Sometimes the
cryoprotectant alone, without reservoir works quite well
Cheers
Christian
Am Dienstag 10 Juli 2012 18:28:30 schrieb m zhang:
regaentDear All,
I am sure this question was discussed before. But I am wondering
Sucrose, sorbitol, Splenda, trehalose, etc, but instead of 25% (is that w/v or
v/w?), try using 100% saturated in reservoir, 75% saturated in reservoir, or
50% saturated in reservoir. You will have to TEST these. See also this
webinar on cryocrystallography which shows how to make these
Give a list of all you have tried?
JPK
On Tue, Jul 10, 2012 at 12:22 PM, Muhammed bashir Khan
muhammad.bashir.k...@univie.ac.at wrote:
Dear All;
Could somebody give a nice suggestion how the following type crystal could
be optimized, I almost tried everything.
Crystal Image is attached
A nice review of cryosalts is available here:
http://dx.doi.org/10.1107/S090744497587
For crystals that don't seem to survive paratone-N, I recommend using
a microscope equipped with a polarizer. The refractive index of
paratone-N is much closer to that of protein crystals than that of
Hi Min,
I agree with Christian Roth, try malonate at high concentration, 2.8 molar
is enough. I suggest to adjust the pH to about the value of your
xtallization condition.
To avoyd salt xtals formation, humidify the environment, some wet paper
around the drop can do the job!
cheers
anna
Have you tried multiple rounds of micro-seeding?
---
Greg Costakes
PhD Candidate
Department of Structural Biology
Purdue University
Hockmeyer Hall, Room 320
240 S. Martin Jischke Drive, West Lafayette, IN 47907
Dear Muhammed,
In my experience, crystals like that are likely made up of contaminated or
non-homogeneous protein. Have you run NATIVE PAGE and IEF gels to determine the
purity of your sample? Is it the correct MW by mass spec without contaminating
peaks?
Good Luck!
Bryan
From: CCP4
Hi,
In my experience, it is very very very difficult to optimize this needle like
crystal. Always give up.
Good luck!
Dear All;
Could somebody give a nice suggestion how the following type crystal could
be optimized, I almost tried everything.
Crystal Image is attached
Crystal condition:
Always give up.
...definitely not the kind of guy I want to sit up front in an airliner…
Best regards, BR
-
Bernhard Rupp, ATP-B737, CFII-MEI
Vienna Air International
Professional Aviation Services
001 (925) 209-7429
You can sometimes cryoprotect crystals like this with the Mitegen low viscosity
cryo oil and their micro mount loops. If that doesn't work, then you can
gradually raise the concentration of sucrose or ethylene glycol so that your
crystals freeze well. I don't think it should take anything
One postdoctoral position funded by NIH is available immediately at the Center
for Membrane Biology, Department of Biochemistry and Molecular Biology, The
University of Texas Houston Medical School (http://www.uth.tmc.edu/cmb/). The
fellow will focus on structural determination of membrane
Hi people,
We are refining a structure with sulfates and we are getting the Chiral volume
outliers issue. I understand the problem as being computational where the
oxygens are in reality equivalent but computationally named differently. I have
seen the recent Acta Cryst D paper (April 2012 -
Sorry I should have added, that the issue occurs following refinement in
refmac. (error in log file and SO4's are distorted)
_
Joel Tyndall, PhD
Senior Lecturer in Medicinal Chemistry
National School of Pharmacy
University of Otago
PO Box 56 Dunedin 9054
New
Hi all,
recently，I want to use DelPhi to calculate the Electrostatic potentials of
DNA.but in the manual,i can not find the method to create the inputfile fort.11
、fort.12 and fort.13.Does anyone have experience on this? Please suggest
Thank you in advance
Sincerely
dengzq
On 07/11/2012 11:36 AM, dengzq1987 wrote:
Hi all,
recently，I want to use
DelPhi to calculate the Electrostatic potentials of DNA.but in the
manual,i can not find the method to create the inputfile fort.11
、fort.12 and fort.13.Does anyone have experience on this? Please suggest
Why not
Dear Muhammad,
I had a similar case, and the crystals could indeed be optimized. A few
things to check first,
1) How long does it take for the needles to appear? Sometimes, if the
protein is degraded/ cleaved over time, a small population (possibly a
fragment of the whole
protein) from the
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