>Packing billions of copies into a compact lattice
Not so compact there is 40-80% water
>freezing it to 100K
We have frozen many times protein solutions in liquid nitrogen and then thaw
and were working OK
> non-physiological amounts of salt and various organics
What is the amount of salt and osmotic pressure in the cell??
>non-physiological pH too
What is the non-physiological pH too? I am sure that some enzymes they are
not working in pH 7. Also most of the proteins they have crystallized in pH
close to 7 so I would not say non-physiological.
George
PS There are lots of solution NMR structures as well supporting the
physiological crystal structures
-----Original Message-----
From: CCP4 bulletin board [mailto:[log in to unmask]] On Behalf Of Nat
Echols
Sent: Friday, February 10, 2012 10:35 PM
To: [log in to unmask]
Subject: Re: [ccp4bb] Crystal Structures as Snapshots
On Fri, Feb 10, 2012 at 12:29 PM, James Stroud <[log in to unmask]> wrote:
> How could they not be snapshots of conformations adopted in solution?
Packing billions of copies of an irregularly-shaped protein into a
compact lattice and freezing it to 100K isn't necessarily
representative of "solution", especially when your solution contains
non-physiological amounts of salt and various organics (and possibly
non-physiological pH too).
-Nat
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