Table 1.
Inhibitory Kinetic Parameters for Durlobactam Against Representative β-lactamases and Penicillin-Binding Proteins
| β-lactamase/PBP | k 2/K (M−1s−1) | k off (s−1) |
|---|---|---|
| TEM-1 (class A) | 1.4 ± 0.6 × 107 | 1.4 ± 0.2 × 10−3 |
| KPC-2 (class A) | 9.3 ± 0.6 × 105 | 1.0 ± 0.1 × 10−3 |
| ADC-7 (class C) | 1.0 ± 0.1 × 106 | 8.0 ± 0.1 × 10−4 |
| OXA-24 (class D) | 9.0 ± 0.2 × 103 | 1.7 ± 0.1 × 10−5 |
| Acinetobacter baumannii PBP1a | 18 ± 0.6 × 101 | Not determined |
| A. baumannii PBP2 | 1.8 ± 0.6 × 103 | Not determined |
| A. baumannii PBP3 | 3.37 ± 0.06 | Not determined |
Source: [23–25]. The k2/K value represents the acylation rate, or how quickly durlobactam gets bound to a β-lactamase or PBP; the higher the number, the faster the reaction. The koff value indicates how quickly durlobactam dissociates from the β-lactamase; the lower the number, the slower durlobactam comes off the β-lactamase.
Abbreviation: PBP, penicillin-binding protein.