Crude membrane pellets were solubilized with the respective substances at indicated temperature and duration. After centrifugation, precipitation of supernatant and trypsin digestion, the peptides were identified by shotgun LC/MS. Normalized intensity profiles of each protein are presented. The data set is filtered for membrane proteins.

Copolymers and detergents are effective tools to get membrane proteins in solution. The analyzed substances will be tested for their ability to isolate membrane proteins from membranes.

“Not a number”, this means that no peptides of the corresponding protein were found in the LC/MS experiment with this specific solubilization reagent in this context not detected.

Intensities were normalized to an interval from zero to 1. The lowest value is zero, the highest one.

You can either enter the UniProt number or the gene name to search for you protein of interest. Also try to enter variants of the gene name. Alternatively you can also enter a protein family name (e.g. GPCR or Toll-like receptor).

Intensities are color coded: red is highest, light yellow lowest.
The color scale for the different solubilization conditions represents different intensities. The darker orange - red a color is, the higher the intensity.

Solubilization of membrane proteins is something that cannot be predicted. Generally, one has to work with several substances like Copolymers and detergents to find the best substance for the protein. Copolymers have the advantage that lipids from the membrane are solubilized in complex with the membrane protein which can positively influence the stability and activity of the membrane protein. Therefore, the highest possible intensity does not automatically mean the highest activity; several substances should be tested. This tool is intended as a starting point to perform further optimizations yourself.

There are roughly 21.000 human proteins annotated in Swissprot. Roughly 5000 of them are membrane proteins with transmembrane domains ranging from 1 to 37. Approx. 2000 – 3000 of them are permanently expressed and can theoretically be detected in Hek293 cell line.

This can occur, as there are many membrane proteins. Look for a matching protein of the same family first. If no information is available on the protein of interest, a solubilization screening with as many different substances as possible should be performed.