Refractive index‐based determination of detergent concentration and its application to the study of membrane proteins

The concentration of detergent in membrane protein preparations can have a critical role on protein stability, function, and the potential for crystallization. Unfortunately, dialysis or protein concentration can lead to an unknown amount of detergent in the final membrane protein preparations. Here...

Full description

Saved in:
Bibliographic Details
Published in:Protein science 2005-08, Vol.14 (8), p.2207-2211
Main Authors: Strop, Pavel, Brunger, Axel T.
Format: Article
Language:English
Subjects:
C12E9, polyoxyethylenedodecyl ether
Chromatography, Gel
CMC, critical micelle concentration
DDM, n‐dodecyl‐β‐D‐maltopyranoside
detergent concentration
Detergents - analysis
Detergents - isolation & purification
dn/dc
dn/dc, change of refractive index as a function of concentration
For the Record
FOS14, n‐tetradecylphosphocholine
LDAO, lauryldimethylamine‐N‐oxide
MALLS, multi‐angle laser light scattering
Membrane Proteins - chemistry
Membrane Proteins - isolation & purification
micelle size
Micelles
Reference Standards
refractive index
Refractometry - methods
Refractometry - standards
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The concentration of detergent in membrane protein preparations can have a critical role on protein stability, function, and the potential for crystallization. Unfortunately, dialysis or protein concentration can lead to an unknown amount of detergent in the final membrane protein preparations. Here we present a method for the determination of detergent concentration based on refractive index of the detergent solution. This method was applied to quantitate the amount of detergent remaining in solution after concentration in various concentrators. We found that the ability of the tested detergents to pass through the molecular weight cutoff membrane correlates well with detergent micelle size. Therefore, the micelle size can be used as a rough guide to estimate the retention of a given detergent in various molecular weight cutoff concentrators. The refractive index method is exceptionally informative when coupled with size exclusion chromatography and light scattering, and can be used to determine the oligomeric state of the membrane protein, the size of a protein‐associated micelle, as well as the amount and size of the unbound detergent micelle.
ISSN:0961-8368
1469-896X
DOI:10.1110/ps.051543805