Hi Liuqing,
The scheme you suggested (or heard) of using Ion-exchange at the end can be
useful to separate protein with same net charge but different conformations.
Ciao
On Fri, Nov 17, 2017 at 1:49 PM, Gianluca Cioci
wrote:
> Dear All
>
> The ion exchange has the
Do the following.
1) Perform density modification (NCS averaging and solvent flattening)
2) Run the new phases through a model building program (Buccaneer works for all
resolutions, Arp/wArp works well for better than ~2.7 Å or better resolution)
If this doesn’t give you a better quality model
R=50% at a resolution of 2.2 Å is a lot different to 50% at, say, 3.5 Å
resolution. What happens if you refine it at 3.0 or 3.5 Å ?
What's the model vs sequence % identity ?
Phil Jeffrey
Princeton
On 11/17/17 3:23 PM, Yue Li wrote:
Dear all,
I have several datasets (one best resolution
Dear all,
I have several datasets (one best resolution reaching 2.2A), giving C2 space
group, two molecules in an asymmetry unit (65.1% of solvent content). When
running MR using a template (<20% sequence identify to the target molecule), I
got a solution with high TFZ (23.7) and LLG (842).
Dear All
The ion exchange has the great advantage ,over other tecniques, to
concentrate the protein.
Histrap+sec is a big classic in protein purification but times it is worth
considering other schemes. Why doing a SEC? It is for removing aggregates
or a contaminant ? It the latter case probably
Hi Liuqing,
I would not recommend SEC. SEC does not give that great of a separation
unless your contaminant is greatly different in size. Instead of SEC, you
might want to consider hydrophobic interactions chromatography (HIC). You
can add your ammonium sulfate directly to your eluted protein
Hi Liuqing,
I agree with what Pascal has already written and can add something from my
experience.
In one case I needed to purify a protein using gelfiltration to control the
exact composition of the buffer before preparing for the ion exchange.
The protein was only stable in high salt buffers.
Hi liuqing,
It is more usual to finish with a sec because you control the composition
of the final conditioning buffer of your sample and remove any aggregates.
We personally favor the following sequence
iMac - desalt - iex if necessary - sec
Desalt meaning one of those small Pd10 like column
Hello,
I am not sure but I had the same kind of problem using ccp4 on Linux "exotic"
distribution which use python 3 by default.
Check that your Linux installation has python 2.x as default python in your
environement.
Hope this guide a bit the trouble shooting.
Nicolas
Horrell,
Hello CCP4bb,
I'm having some trouble with my installation of CCP4i2. I keep getting a
persistent error about the "Wrapper" in various programs and am not sure what I
need to do to fix it. I have tried reinstalling via the package manager (64b
linux) and still get the error. So far it has
Hello everyone!
I have listened someone suggested that, first use affinity chromatography
(Ni-NTA), then use SEC (superdex200 increase), and finally used ion exchange
(monoQ), to purified protein, which will be used to crystallization.
My question is why the monoQ used in the finally
Hi,
The structural biology CRO SARomics Biostructures in Lund, Sweden, has an open
position for a protein crystallographer. The application deadline is 1st
December. See here for details:
https://www.saromics.com/About/About/Career.html
Best regards
Derek Logan
Please note that the Early bird deadline for the forthcoming CCP4 Study Weekend
in 10-12 January 2018 is 19th November 2017 i.e. this Sunday.
After this date, no standard student bursaries will be available and the
registration fee will increase from £240 to £290 for the final 3 weeks of
We have used it in this way...
coot --pdb input.pdb ---auto input.mtz --script script.com
and then, in file "script.com", you write the corresponding instructions...
(set-go-to-atom-molecule 0)
(set-go-to-atom-chain-residue-atom-name "B" 42 " CA ")
Martin
14 matches
Mail list logo