deepbluedna, on Feb 4 2009, 09:20 AM, said:
After expressing my protein with the IPTG induction in BL21 cells. I got not activity of my protein, but there is a band at the correct MW. Then I sent my protein for N-term sequencing in case, after I got the sequence back I found out that the sequence match part of my protein, which means 15 amino acids are missed after methionine. I wonder if it could be caused by the expression of the purification process? Did this ever happen to anyone here? I started a second time expression and got the right band again but no activity. Problem for me:(
Need help here. Thanks in advance
My first guess is that you have a Met about 15 residues in from your start, right? If so, the transcription/translation machinery has jumped past the true start codon. If not, there is something very strange going on.
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