Re: [ccp4bb] Criteria for Ligand fitting

2012-04-24 Thread Herman . Schreuder
Dear Naveed, From your description, I get the impression that indeed you have a partially bound inhibitor. However, I do have some comments: At 1.7 Å, you should refine a group-occupancy for your inhibitor. With a partially bound inhibitor, the density in your active site will be a

Re: [ccp4bb] high temp factor in coot!

2012-04-24 Thread Tim Gruene
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Dear Qixu, there is no contradiction in your quotes and what you are thinking: * The standard deviation has the same unit as the values you're measuring. * I always think that the unit of deviation is the same to the values we're measuring.

Re: [ccp4bb] high temp factor in coot!

2012-04-24 Thread Qixu Cai
Dear Tim, Sorry about my typo. I just want to know what is the unit of variance when the standard deviation has the same unit as the values? What's the definition of variance actually? Thank you very much! 在 2012年4月24日 下午4:01,Tim Gruene t...@shelx.uni-ac.gwdg.de写道: -BEGIN PGP SIGNED

Re: [ccp4bb] Criteria for Ligand fitting

2012-04-24 Thread Pandit, Jayvardhan
Naveed, From your description, it appears as if some covalent changes have occurred in the 2 weeks of soaking. Perhaps your inhibitor is getting turned over by the enzyme ? Also, if you don't have your inhibitor in the cryo, you could be soaking it out prior to data collection, which may

Re: [ccp4bb] high temp factor in coot!

2012-04-24 Thread Ed Pozharski
http://mathworld.wolfram.com/StandardDeviation.html On Tue, 2012-04-24 at 09:13 +0800, Qixu Cai wrote: Dear Ed, Why the variance is the square of standard deviation? thank you very much! 在 2012年4月23日,20:53,Ed Pozharski epozh...@umaryland.edu 写道: On Sun, 2012-04-22 at 12:47 +0530,

Re: [ccp4bb] Criteria for Ligand fitting

2012-04-24 Thread Colin Groom
Interesting. One of the most helpful ways of ascertaining whether you do have a bound ligand (or, as Jay suggests, bound but modified ligand/protein) is, of course, to compare the electron density you see in the complex with the corresponding unliganded (let’s say apo) complex (in your case,

Re: [ccp4bb] Criteria for Ligand fitting

2012-04-24 Thread Enrico Stura
Naveed, You mention: The active site hydrophobic crown had been reported to re-orient and a charged residue is known to position for forming a salt-bridge with similar ligands. When you induce structural changes on ligand binding, lattice forces that stabilize one particular conformation may

Re: [ccp4bb] Anaerobic glovebox crystal cryo-cooling

2012-04-24 Thread Bryan Lepore
On Tue, Apr 24, 2012 at 10:20 AM, David Gallagher dt...@mrc-mbu.cam.ac.uk wrote: I've been using a Belle technologies anaerobic glovebox with in built microscope and liquid nitrogen dewar port [...]   plunging loops straight into vials preloaded into an ESRF puck why, why, why, and why?

Re: [ccp4bb] Anaerobic glovebox crystal cryo-cooling

2012-04-24 Thread Nian Huang
Hi, Sometimes the forming of ice is due to the high humidity in the air. I recommend to put a dehumidifier in the room or silicone gel in your camber. Nian On Tue, Apr 24, 2012 at 9:52 AM, Kelly Daughtry kellydaugh...@gmail.comwrote: Is there room in the LN2 to plunge directly in, then

Re: [ccp4bb] Anaerobic glovebox crystal cryo-cooling

2012-04-24 Thread Peter Moody
We have a similar setup at Leicester, but its new enough not to have got that far yet! I'd be interested in any replies you get. best wishes, Peter On 24 April 2012 15:20, David Gallagher dt...@mrc-mbu.cam.ac.uk wrote: Hi all, I've been using a Belle technologies anaerobic glovebox with

Re: [ccp4bb] Anaerobic glovebox crystal cryo-cooling

2012-04-24 Thread Patrick Loll
Think about hyperquenching (a high-falluting name meaning to use a stream of gas to blow off the cold layer that accumulates above the surface of the liquid nitrogen). We just blow some nitrogen at the surface of the dewar, very low tech...but it works. Importantly, you can use a more leisurely

Re: [ccp4bb] Anaerobic glovebox crystal cryo-cooling

2012-04-24 Thread David Gallagher
Thanks for all the input. I'll try to respond to some of the points made. Kelly - the dewar is quite narrow in diameter so there's little space to maneuver, the puck fits snugly. Unfortunately we are limited by the size of the port so we can't use a larger one. Additionally the dewar sits

[ccp4bb] hey

2012-04-24 Thread E rajakumar
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[ccp4bb] resolution on PDB web page

2012-04-24 Thread Phoebe Rice
I just noticed that the PDB has changed the stated resolution for one of my old structures! It was refined against a very anisotropic data set that extended to 2.2 in the best direction only. When depositing I called the resolution 2.5 as a rough average of resolution in all 3 directions, but

Re: [ccp4bb] Criteria for Ligand fitting

2012-04-24 Thread Naveed A Nadvi
Dear Crystallographers, Thank you all for responding! I will try to respond to the suggestions collectively. I did however have some questions for some of these suggestions... @Herman Schreuder: I have performed refinement with alt conform as you suggested. I am not sure how to do