Questions about protein quantification - from the industry
Trond Erik Vee Aune
(by trondaun from REMOVE.nt.ntnu.no)
Tue Jun 3 01:54:49 EST 2008
> Hi Trond,
> what about beta-galactosidase or beta-glucuronidase? There are
> chromogenic and fluorogenic subtrates available.
Are you suggesting using the alpha subunit of beta-galactosidase as a
reporter tag (analogous to blue/white screening)? If so I worry that the
signal strength will be inhibited by low levels of the omega subunit
(expressed from the chromosome). And I don't know if this will function
at all in other bacteria except E. coli.
Another possibility is of course to use the whole beta-galactosidase as
a reporter, and this is presumably what you meant, but unfortunately
this protein is very large (1021 aa) and might therefore not be suitable
as a reporter tag (?). And would the presence of chromosomal copy raise
the background too high?
This last question is relevant for beta-glucuronidase too.
Unfortunately, in addition, use of the GUS assay is covered by patents,
so this might be an expensive alternative.
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