Table 1.
Parameters k cat and K m as measured in the kinetic assay
| RA sera (anti-hPAD4 emission signals [x106]) | Purified total IgG | Purified total IgG depleted from anti-hPAD4 antibodies | Control depletion | ||||||
|---|---|---|---|---|---|---|---|---|---|
| K m [mM] | k cat [s−1] | k cat /K m [s−1 M−1] | K m [mM] | k cat [s−1] | k cat /K m [s−1 M−1] | K m [mM] | k cat [s−1] | k cat /K m [s−1 M−1] | |
| Anti-PAD4-positive sera | |||||||||
| RA26 (1.59) | 1.35 | 5.26 | 3,890 | 0.85 | 3.38 | 3,970 | 0.8 | 3.38 | 4,225 |
| RA35 (1.43) | 1.60 | 3.75 | 2,340 | 1.60 | 3.75 | 2,340 | 1.60 | 3.75 | 2,340 |
| RA64 (1.59) | 1.40 | 5.20 | 3,710 | 1.50 | 5.60 | 3,730 | 1.50 | 5.20 | 3460 |
| RA78 (1.02) | 1.40 | 5.26 | 3,750 | 1.30 | 5.26 | 4,040 | 1.25 | 5.26 | 4,200 |
| RA99 (1.14) | 1.00 | 3.38 | 3,380 | 1.25 | 3.00 | 2,400 | 1.30 | 3.00 | 2,300 |
| Anti-PAD4-negative sera | |||||||||
| RA39 (0.023) | 1.20 | 5.51 | 4,591 | 1.49 | 6.19 | 4,154 | 1.25 | 4.87 | 3,896 |
| RA55 (0.021) | 1.50 | 4.50 | 3,000 | 1.75 | 3.60 | 2,050 | 1.45 | 3.38 | 2,330 |
| Healthy control sera | |||||||||
| HC74 (0.032) | 1.50 | 2.25 | 1,500 | 1.20 | 2.63 | 2,192 | nd | nd | nd |
| HC80 (0.016) | 0.75 | 2.40 | 3,200 | 0.75 | 2.63 | 3,506 | 0.75 | 2.25 | 3,000 |
| HC89 (0.046) | 1.20 | 3.38 | 2,810 | 1.20 | 3.00 | 2,500 | 1.20 | 3.00 | 2,500 |
| Buffer control (0.005) | 0.90 | 2.63 | 2,900 | ||||||
Recombinant hPAD4 was incubated with purified IgG or with MOPS buffer. The values shown are from one representative experiment. Anti-hPAD4 emission signals were obtained in the hPAD4-specific fluorometric immunoassay