bipin at iastate.edu (Bipin K Dalmia) writes:
>i've finally managed to purify enough of a protein expressed as a GST
>fusion protein and cleaved with thrombin. (the protein is greater
>than 99% pure on a silver-stained sds-gel). now for long term storage
>(the protein will be used as a standard in quantitative ELISAs) i've put
>the protein in the following concoction. the protein seems to be pretty
>stable (at least soluble, i'm not too concerned about activity) during
>the purification steps.
>50 mM tris-hcl pH 8.0
>125 mM nacl
>0.5 mM PMSF
>0.5 mM EDTA
>1 mM DTT
>0.05 % NaN3
>1 % triton x-100
>50 % glycerol
>protein concentration= 1.1 mg/ml
you can save the PMSF, it will decay anyway within minutes in aqueous solution.
I assume you included PMSF during your purification procedure, so all serine
(PMSF sensitive) proteases should be inactivated irreversibly.
My proteins were more stable when stored in higher concentrations (>5mg/ml)
Just my 0.02$.
* Robert Slany Ph.D., Institut fuer Biochemie, Fahrstr. 17, Germany *
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