TABLE 1.
Mean improvements of 2F5 Fab productivity obtained by cooverexpression of novel secretion helper factors relative to the control culture valuea
| Folding factor | Mean improvementb | P valuec | Statistical significanced |
|---|---|---|---|
| PDI1 | 1.7 | 0.00032 | *** |
| CUP5 | 1.7 | 0.00157 | *** |
| SSA4 | 1.6 | 0.00156 | *** |
| BMH2 | 1.5 | 0.00002 | *** |
| KIN2 | 1.5 | 0.00060 | *** |
| KAR2 | 1.5 | 0.22167 | |
| HAC1 | 1.5 | 0.00022 | *** |
| ERO1 | 1.4 | 0.00059 | *** |
| SSE1 | 1.4 | 0.00688 | *** |
| BFR2 | 1.4 | 0.03811 | ** |
| COG6 | 1.2 | 0.18851 | |
| SSO2 | 1.2 | 0.27459 | |
| COY1 | 1.2 | 0.07546 | |
| IMH1 | 1.1 | 0.26235 | |
| SEC31 | 1.0 | 0.08838 | |
| Control | 1.0 |
The previously characterized secretion helper factors PDI1, KAR2, HAC1, ERO1, and SSO2 are included for comparative reasons and highlighted in bold.
The six best clones of each tested secretion helper factor construct were compared to the six best clones of the control construct (empty pGAPHis vector). The mean improvement factor for two screening rounds is shown. The strain used in this study was P. pastoris SMD1168, containing the 2F5 Fab genes under the control of the GAP promoter, preselected for high Fab secretion prior to transformation with the pGAPHis vector for constitutive coexpression of the helper genes.
Statistical significance of the mean improvement of each tested secretion helper factor construct determined by a combined Student t test.
***, P ≤ 0.01; **, P ≤ 0.05.