Table 2.
Comparison of expression yields using the Tat or Sec export pathways
| Protein of interest | Signal peptide1 |
Yield (mg/L) |
Tat/Sec ratio (%)2 |
Reference |
|---|---|---|---|---|
| E. coli expression3 | ||||
| MBP | MBP | 9.8 | - | This study |
| TorA(+10) | 4.6 | 47 | This study | |
| TorA(+6) | 5.0 | 51 | This study | |
| TorA(+0) | 5.9 | 60 | This study | |
| GFP | PelB | nm | nd | This study |
| TorA | 10â15 | nd | (Barrett et al., 2003) | |
| MBP-GFP | MBP | 0.4 | - | This study |
| TorA | 2.6 | 650 | This study | |
| scFv 26.10 | PelB | 1.0 | - | (Ribnicky et al., 2007) |
| TorA4 | 0.1 | 12 | (Ribnicky et al., 2007) | |
| scFv13.R4 | MBP | 0.01 | - | This study |
| TorA | 0.06 | 600 | This study | |
| MBP-scFv13.R4 | MBP | 8.4 | - | This study |
| TorA | 0.5 | 6 | This study | |
| human tPA (truncated) | StII | 140.05 | - | (Kim et al., 2005) |
| TorA | 44.85 | 29 | (Kim et al., 2005) | |
| S. lividans expression6 | ||||
| S. lividans XlnB1 | XlnB17 | nr | - | (Gauthier et al., 2005) |
| XlnC8 | nr | 33 | (Gauthier et al., 2005) | |
| S. lividans XlnB2 (truncated) | XlnB1 | nr | - | (Gauthier et al., 2005) |
| XlnC | nr | 70 | (Gauthier et al., 2005) | |
| S. equisimilis streptokinase | Vsi9 | 4 | - | (Pimienta et al., 2007) |
| XlnC | 0.1â0.2 | 4 | (Pimienta et al., 2007) | |
| human TNFa | Vsi | 23.0 | - | (Schaerlaekens et al., 2004) |
| XlnC | 1.6 | 7 | (Schaerlaekens et al., 2004) | |
| XyyZ10 | 1.4 | 6 | (Schaerlaekens et al., 2004) | |
| human IL-2 | Vsi | 10.4 | - | (Schaerlaekens et al., 2004) |
| XlnC | 4.8 | 46 | (Schaerlaekens et al., 2004) |
All signal peptides derived from E. coli unless otherwise noted. Sec-dependent signal peptides are listed in italics.
Tat/Sec ratio calculated by dividing yield measured for Tat expression by the value measured for Sec expression. All values represent yield obtained from periplasmic or supernatant fraction.
All proteins expressed in E. coli were purified from the periplasm.
Yields obtained using high-cell E. coli density fermentations.
Expression via the Tat system was achieved using strain FĂ 113 that has a more oxidizing cytoplasm than wildtype strains of E. coli
All proteins expressed in Streptomyces lividans were secreted and purified from the medium.
Sec signal peptide derived from S. venezuelae xylanase B1 (XlnB1).
Tat-dependent signal peptide derived from S. lividans xylanase C (XlnC).
Signal peptide derived from S. venezuelae CBS762.70 subtilisin inhibitor (Vsi).
Signal peptide derived from S. lividans tyrosinase (XyyZ).
nd = not determined; nm = not measurable (protein is completely undetectable); nr = not reported.