Dear Buddies,
I truly appreciate many of you are so kind to spend your time in
replying my email with a variety of suggestions regarding this strange
problem. Most of you have pointed to oxidation damage. We tested
quickly but high concentrations of DTT or TCEP including EDTA and/or
glyc
I think I know another protein that does this: gelatin! (Well, not the
crystallization part...)
Jacob
On Fri, Sep 16, 2011 at 2:41 PM, Phoebe Rice wrote:
> Gamma delta resolvase catalytic domain stock solutions used to make a nice
> clear jelly at 4 degrees, but it was perfectly reversible by w
Gamma delta resolvase catalytic domain stock solutions used to make a nice
clear jelly at 4 degrees, but it was perfectly reversible by warming the sample
to room T. In fact, one mutant crystallized in the stock tube after a few
trips in and out of the fridge. The crystals didn't diffract very
Hi Aidong,
I've seen this in protein samples that have been snap frozen then thawed on
ice. Thawing at room temperature (or in the hand) stopped this state forming.
Could temperature be the issue? Maybe try 10C or leave the samples on the bench
for a while and see if the state is reversible?
D
DTT), but unfortunately you may just have
to work with the protein within a couple days of finishing the prep.
Mike
- Original Message -
From: "Patrick Loll"
To: CCP4BB@JISCMAIL.AC.UK
Sent: Tuesday, August 30, 2011 9:06:52 AM GMT -08:00 US/Canada Pacific
Subject: Re: [ccp4bb]
@JISCMAIL.AC.UK
Subject: Re: [ccp4bb] Protein preps become a jelly
I have had protein crystals (so very high protein concentration) that
turn into gummy bear-like objects, where instead of crumbling they are
like, well, a gummy bear or a piece of rubber. I attributed it to
oxidation or other
Certainly not unprecedented, or even that unusual (I remember making gels from
BSA and IgG solutions during grad school rotations). Gel formation usually
requires crosslinking, so consider whether you might be getting adventitious
disulfide bond formation.
Pat
On 30 Aug 2011, at 11:31 AM, aido
Not necessarily uncommon. To minimize
protein-protein interactions that might be causing gelation, you
might change the pH of the solution so that is is not close to the
pI, use a small amount of chelator to sequester metal ions, and
maintain a modest ionic streng
I have had protein crystals (so very high protein concentration) that turn
into gummy bear-like objects, where instead of crumbling they are like,
well, a gummy bear or a piece of rubber. I attributed it to oxidation or
other chemical ageing processes. I am sure others will have suggestions for
p
