Table I.
Relationship between the net charge of different antibody regions and antibody specificity for clinical-stage mAbs
| Antibody regions | P-value | Area under curve (AUC) | Direction of relationship, net charge vs. specificity |
|---|---|---|---|
| Fv | 0.0112 | 0.66 | − |
| VH | 0.011 | 0.66 | − |
| VL | 0.41 | 0.57 | − |
| Variable framework | 0.12 | 0.59 | + |
| CDRs | 0.00025 | 0.74 | − |
| Heavy CDRs | 0.010 | 0.67 | − |
| H1 | 0.22 | 0.54 | + |
| H2 | 0.024 | 0.64 | − |
| H3 | 0.046 | 0.62 | − |
| Light CDRs | 0.0049 | 0.70 | − |
| L1 | 0.041 | 0.62 | − |
| L2 | 0.0069 | 0.64 | − |
| L3 | 0.57 | 0.60 | − |
Logistic regression analysis of the specificity of 137 clinical mAbs as a function of the theoretical net charge of different antibody regions at pH 7.4. Low antibody specificity was defined as non-specific binding (ELISA) values >1.9 signal/background (Jain et al., 2017). The P-value for the coefficient of the independent variable of the logistic regression function and the area under the curve (AUC) for the receiver operating characteristic curves are reported. A negative relationship between net charge and specificity means that specificity is reduced as net charge is increased, and vice versa for the positive relationship.