[3dem] correspondance between protein populations in solution and on the grid?

[vincent Chaptal]

Hi,

when performing enzymatic assays, we look at triplicates and we can 
observe some degree of variation between experimental triplicates (also 
between biological triplicates but no exactly the topic is this 
question). Sometimes, I even wonder how homogeneous my purified protein 
is in the tube, and if I pipet a true homogeneous solution.

When we observe the same solution under the microscope, is it the same 
population of particles in 2D/3D classes and in the test tube?
If we see 40% of conformation A, and 60% of conformation B in 
initial/crude 3D classification, can we make the claim that it 
represents the actual population as in lipuid?
I was also wondering if conformation A and B would enter foilholes 
similarly or if some conformations enter holes more preferentially?

I couldn't find litterature on the matter, but I image it's been looked 
at; could you point me to the right refences?

This discussion on micro-domains in solution, or micro-concentration of 
particles in liquid, becomes more vivid when using pico-liters type of 
deposition on grids as we see coming (spotiton, etc...). Should we then 
collect 3 grids to link to structural enzymology?

Looking forward to your comments.
Best
Vincent

-- 

Vincent Chaptal, PhD

Director of GdR APPICOM

Drug Resistance and Membrane Proteins Lab


MMSB -UMR5086

7 passage du Vercors

69007 LYON

FRANCE

+33 4 37 65 29 01

https://urldefense.proofpoint.com/v2/url?u=http-3A__www.appicom.cnrs.fr&d=DwICaQ&c=-35OiAkTchMrZOngvJPOeA&r=L7-zyQ-04fFCMRqzLIOnx7H0exGZHwIQe_wMPuY600I&m=qrt2reBNwFsAVKl8vw75LCHg-wJUzh2f0l8AbUbjYMU&s=D4e4wIyVRpIAoUnMB_OQnn1FTcxriRAj2xlohCaWC-I&e= 

https://urldefense.proofpoint.com/v2/url?u=http-3A__mmsb.cnrs.fr_en_&d=DwICaQ&c=-35OiAkTchMrZOngvJPOeA&r=L7-zyQ-04fFCMRqzLIOnx7H0exGZHwIQe_wMPuY600I&m=qrt2reBNwFsAVKl8vw75LCHg-wJUzh2f0l8AbUbjYMU&s=dHx-_VFkG1dS-Xdza6TSpFoT0G73e67P-UeiCIu6B34&e= 


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ncmir.ucsd.edu/pipermail/3dem/attachments/20210810/a25ee206/attachment-0001.html>