> Zhang Bo wrote:
>> Dear Netters,
> We have expressed a recombinant protein in E.Coli, and we get the
> purified product. But when we determined its molecular weight by
> MS(mass spectrometry), it has 500 dalton more than expected. Then we
> sequenced the product, its N-terminal sequence and the last two
> amino acid are O.K. So I wonder why?
Even in E.coli, some proteins get modified after translation. I'm
quite sure that there is some glycosylation, but there might be other
modifications, too.
Frank
--
Frank Fuerst, PhD-Student
Department of physical biochemistry
Potsdam Unversity, Germany
