TABLE 2.
Kinetic parameters of reversible inactivation of serine β-lactamases by VNRX-5236
| Parameter | Data for: |
|||
|---|---|---|---|---|
| KPC-2a | CTX-M-15 | SHV-5 | P99AmpC | |
| k2/Ki (104 M−1s−1) | 2.9 ± 0.07 | 4.8 ± 0.9 | 1.1 ± 0.16 | 6.0 ± 0.6 |
| k−2 (10−4 s−1) | 2.5 ± 0.1 | 4.5 ± 0.1 | 12.7 ± 0.07 | 24 ± 0.5 |
| t1/2 (min) | 46 ± 2 | 26 ± 0.6 | 6.5 ± 0.04 | 5 ± 0.1 |
| Ki (μM) | 0.11 | 0.01 | 0.04 | 0.02 |
a
KPC-2, Ambler class A Klebsiella pneumoniae carbapenemase; CTX-M-15, Ambler class A cefotaximase-Munich 15 extended-spectrum β-lactamase; SHV-5, Ambler class A sulfhydryl variable β-lactamase; P99AmpC (ACT-C189), Ambler class C chromosomal-encoded β-lactamase; k2/Ki, rate of covalent bond formation; k−2, off rate; Ki, inhibition constant; t1/2, half-life.