For proteins expressed in the cytoplasm, is the presence of biotinylated proteins in the host organism a problem?
No. Generally, the amount of biotinylated proteins in the cytoplasm is very low and does not lead to significant inactivation of the column. In an E. coli extract derived from a 1 L culture with OD 550 = 1, the total biotin content is only around 1 nmol; column capacity is 350 nmol/ml. Even the biotinylated E. coli protein BCCP has a relatively low intracellular concentration and usually does not interfere with purification. To avoid binding BCCP to Strep•Tactin resin, add avidin to the cell lysate before chromatography (20 mg/L for an E. coli culture at OD 600=1).
Related Questions
- Is the presence of free biotin in the medium (in case of proteins secreted to the medium) a problem (eukaryotic expression)?
- Is the presence of biotinylated proteins in the host organism in case of proteins expressed in the cytoplasm a problem?
- For proteins secreted into the medium, is the presence of free biotin in the medium a problem (eukaryotic expression)?
