Re: [ccp4bb] larger molecular weight shown by analytic ultracentrifugation

2011-06-03 Thread Lionel
Dear Jerry, Just a few comments on your questions. We tried both SV and SE. SV showed an increasing Sw with decreasing concentrations (Sw varied from 6.9, 7.0, 7.2, 7.4 to 7.522). IN addition, the SV experiments showed a single boundary. However, the boundary was a little broader, between 6

Re: [ccp4bb] larger molecular weight shown by analytic ultracentrifugation

2011-06-02 Thread Chad Brautigam
From: Kushol Gupta kushol.gu...@gmail.com To: CCP4BB@JISCMAIL.AC.UK Sent: Fri, May 27, 2011 9:51:04 AM Subject: Re: [ccp4bb] larger molecular weight shown by analytic ultracentrifugation Hi Jerry – By AUC, do you mean sedimentation velocity (SV)? Both gel filtration

Re: [ccp4bb] larger molecular weight shown by analytic ultracentrifugation

2011-06-02 Thread Jerry McCully
:57 -0700 From: cabrautc...@yahoo.com Subject: Re: [ccp4bb] larger molecular weight shown by analytic ultracentrifugation To: CCP4BB@JISCMAIL.AC.UK Dear Kushol Jerry, I have to take exception to Kushol's contention about SV. As long as the buffer and protein parameters are correct

[ccp4bb] larger molecular weight shown by analytic ultracentrifugation

2011-05-27 Thread Jerry McCully
Dear ALL; I am sorry for this off-topic question about analytic ultracentrifugation (AUC). We recently solved one structure from crystals grown out of PEG4000 plus buffer. Since the crystal was grown from PEG, we think the protein would maintain its native oligomerization state as