Reductive methylation of amino groups (lysines and the N-terminus) is
a fairly routine chemical modification that should drop the solubility
of your protein. An easy-to-use protocol can be found in Walter et al
(2007) Lysine Methylation as a Routine Rescue Strategy for Protein
Crystallization.
.
Regards,
Debanu.
--
Debanu Das,
JCSG, SSRL.
-
-Original Message-
From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of Stephen Graham
Sent: Tuesday, August 07, 2007 11:42 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: Re: [ccp4bb] highly soluble proteins
Reductive
Our lab is trying to crystallize a highly soluble (100+ mg/ml) protein
with a molecular weight of 35 kd.
The protein was screened against 1536 conditions at 20 mg/mL. Most drops
were either clear or produced bubbles (often oily looking). The few
that had precipitate contained high concentrations
Try adjusting the pH close to the pI to reduce solubility.
From: Yvonne Leduc [EMAIL PROTECTED]
Reply-To: [EMAIL PROTECTED]
Date: Tue, 7 Aug 2007 10:17:18 -0600
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] highly soluble proteins
Our lab is trying to crystallize a highly soluble (100+ mg
Yvonne,
Several 'old' proteins have been crystallized from insanely high
concentraitons - concanavalin A for instance can be grown from 100-250
mg/ml solutions by means of 'salting in' using microdialysis. This is of
course highly labor-intensive and also expensive on the protein side.
Look at
First i think that your protein concentration is to low... A common rule is
: protein concentration is good when 50% of your conditions are precipitates
and 50% are clears drops. If most of your drops are clear, i think that you
must increase your protein concentration (a screen from Hampton can
