TABLE 2.
Mutant | Sequon | Turnover rate | Relative turnover/fold reduction | Dissociation constant (Kd) | Relative binding |
---|---|---|---|---|---|
peptides/s | μm | ||||
WT | DQNAT | 1.50 ± 0.04 | 1 | 1.02 ± 0.06 | 1 |
DQNAS | 1.25 ± 0.04 | 0.83/1.2-fold | 4.02 ± 0.20 | 0.25 | |
DQNAC | (3.65 ± 0.12) × 10−3 | 2.43 × 10−3/400-fold | –a | ||
DQNAV | (2.21 ± 0.07) × 10−4 | 1.47 × 10−4/7,000-fold | –a | ||
DQNAA | (3.60 ± 0.12) × 10−4 | 2.40 × 10−4/4,000-fold | –a | ||
W464F | DQNAT | (1.55 ± 0.05) × 10−3 | 1.03 × 10−3/1,000-fold | –a | |
I572V | DQNAT | 1.08 ± 0.02 | 0.72/1.4-fold | 3.75 ± 0.15 | 0.27 |
DQNAS | 0.61 ± 0.02 | 0.41/2.5-fold | 7.71 ± 0.11 | 0.13 | |
DQNAA | (3.60 ± 0.06) × 10−4 | 2.40 × 10−4/4,000-fold | NDb | ||
I572A | DQNAT | 0.33 ± 0.08 | 0.22/4.5-fold | 57.31 ± 0.93 | 0.02 |
DQNAS | 0.13 ± 0.04 | 8.67 × 10−2/12-fold | 165.60 ± 5.50 | 0.01 | |
DQNAA | (1.14 ± 0.05) × 10−4 | 7.60 × 10−5/13,000-fold | ND |
a Peptide binding was observed, but no Kd could be determined because the fluorescence anisotropy signal reached only 30–50% saturation at the limiting PglB concentration of 100–150 μm.
b ND, data not determined.