3 replies to this topic

[genz]

Hello everyone,

After purifying a membrane protein, how do you know if it's stable or functional.
Can anyone suggest a paper or so to measure protein stability.

Thanks!

[saraarasus]

Hi,

I am abit new to the field but I suggest for stability check the protein concentration after some times and see how much is left. Hope this help.
Cheers,
Sara

genz, on Apr 2 2009, 08:37 PM, said:

Hello everyone,

After purifying a membrane protein, how do you know if it's stable or functional.
Can anyone suggest a paper or so to measure protein stability.

Thanks!

[sharath]

If the protein is unstable then it start to aggregate. So measure protein concetration say by lowry or bradford over a period of time (say 12hrs intervals). A sophisticated way to measure stability is by differantial scanning calorimetry.

[rick112]

sharath, on Apr 21 2009, 03:10 PM, said:

If the protein is unstable then it start to aggregate. So measure protein concetration say by lowry or bradford over a period of time (say 12hrs intervals). A sophisticated way to measure stability is by differantial scanning calorimetry.

Measuring protein aggregation (if ur stability problem is obnly aggregation) by lowry or bradford may not such a good idea as you may not find any difference (in this case they may not be detectable via concentration) amd also these method themself have high variation to detect minor chances..
yes DSC is a very good method to check protein stability u can also do SDS-PAGE if its just molecular weight regarding stability related impurities..or RP-HPLC can show you stability related products such as oxidized etc...
all in all you have to use multiple method to come to a final conclusion...
best of luck
P.S> i think you must go for DSC...