TABLE 2.
Affinities of scDb-IgBD fusion proteins for human and mouse IgG and Fab fragments thereof at neutral or acidic pH determined by quartz crystal microbalance (QCM) measurements
| Construct | Ig | Human KD |
Mouse KD |
||
|---|---|---|---|---|---|
| pH 7.4 | pH 6.0 | pH 7.4 | pH 6.0 | ||
| nm | nm | nm | nm | ||
| SpAB | IgG | 9 | 350 | 380 | 15,000 |
| SpAD | IgG | 22 | 148 | 50 | 773 |
| IgG Fab | —a | NDb | — | ND | |
| SpAEZ4 | IgG | 37 | 654 | 78 | 2,480 |
| IgG Fab | — | ND | — | ND | |
| SpGC3 | IgG | 6 | 5 | 67 | 46 |
| IgG Fab | 190 | 150 | 190 | 190 | |
| IgG Fc | 10 | 3.6 | ND | ND | |
| humanized IgG1c | 5 | 4.5 | |||
| PpLC4* | IgG | 1,510 | 1,130 | — | ND |
| IgG Fab | 3,100 | ND | — | ND | |
a —, no binding detected.
b N.D., not determined.
c Trastuzumab was used as IgG1 probe.