Gejing,
I saw that modification here at BMS for a recombinant protein and have been
puzzled as well. We saw up to 3-4 modifications of 183 Da. After LC/MS/MS
peptide mapping analysis we were able to detect modifications of mainly Lys,
Tyr, and possibly Arg (data not as convincing for Arg). That's all the info
that I can give you. I never figured out exactly what the modification was.
This was turning into a thesis project. There does not seem to be anything in
Deltamass that matches with this modification either. Let me know if you find
out what this is.
Mark Hail
Bristol-Myers Squibb
gejing.deng@arcb.us.astra.com wrote:
> Dear ABRF members,
>
> Does anyone know what +183 Da increase to a recombinant protein could be?
> The recombinant has three components: about 40% of correct, 40% of +183 Da
> increased and 20% of +183 X 2 Da increased proteins. All three components
> have identical N-terminal sequences.
> Thanks in advance for any response.
>
> Gejing
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Gejing,
I saw that modification here at BMS for a recombinant protein and have been puzzled as well. We saw up to 3-4 modifications of 183 Da. After LC/MS/MS peptide mapping analysis we were able to detect modifications of mainly Lys, Tyr, and possibly Arg (data not as convincing for Arg). That's all the info that I can give you. I never figured out exactly what the modification was. This was turning into a thesis project. There does not seem to be anything in Deltamass that matches with this modification either. Let me know if you find out what this is.
Mark Hail
Bristol-Myers Squibb
gejing.deng@arcb.us.astra.com wrote:
Dear ABRF members,Does anyone know what +183 Da increase to a recombinant protein could be?
The recombinant has three components: about 40% of correct, 40% of +183 Da
increased and 20% of +183 X 2 Da increased proteins. All three components
have identical N-terminal sequences.
Thanks in advance for any response.Gejing
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