Table 5.
Binding affinities of naturally occurring PAMs to hPg
| Proteins | 37° C | 25° C | ||
|---|---|---|---|---|
| kon (×104 Ms−1) | koff (×10−3 s−1) | Kda (nM) | Kdb (nM) | |
| Class I PAMs: complete a1a2-repeats | ||||
| PAMAP53 | 21.0 ± 3.3 | 4.3 ± 0.3 | 21 ± 2.0 | 2.8 ± 0.9 |
| PAMSS1574 | 56.2 ± 7.9 | 7.5 ± 0.6 | 14 ± 1.0 | 1.4 ± 0.4 |
| Class II PAMs: lacking a1-repeat | ||||
| PAMNS88.2 | n.d.c | 5,700 ± 240c | 1.5 ± 0.4 | |
| PAMSS1448 | n.d.c | 7,000 ± 990c | 30 ± 6 | |
| Class III PAMs: complete a1a2-repeats (+ VHD/DHD between the a1- and a2-repeats) | ||||
| PAMNS233 | 25 ± 8 | 5.6 ± 1.2 | 28 ± 10 | 2.9 ± 1.3 |
| PAMNS455 | 34 ± 13 | 1.4 ± 0.2 | 6.0 ± 2.3 | 0.3 ± 0.1 |
| PAMSS1572 | 17 ± 6 | 5.5 ± 0.7 | 40 ± 7 | 8.0 ± 3.9 |
a
Dissociation constants (Kd) were calculated from koff/kon. All data were collected from triplicate runs and are presented as the mean ± S.D.
b
Dissociation constants (Kd) measured at 25° C were published previously (Qiu et al., 2018) and are listed here for reference.
c
n.d., not determined. The very fast off rates for hPg to the Class II PAMs did not allow accurate calculations to be made by kinetic analyses of binding. Therefore, the steady state method was used to calculate the Kd values at 37° C.