Table 2.
Substrate | Buffer | Deacylation rate k3 (s−1) | ||
---|---|---|---|---|
K70A | K70E | K70D | ||
Bocillina | 50 mM NaH2PO4, pH 7.0 | 0.00022±0.00002 | < 4.0 × 10−5 | < 4.0 × 10−5 |
Ampicillinb | 50 mM NaH2PO4, pH 7.0 | 0.00012±0.00001 | < 4.0 × 10−5 | < 4.0 × 10−5 |
50 mM NaH2PO4, 9 mM Na2CO3, pH 7.0 | 0.00090±0.00004 | < 4.0 × 10−5 | < 4.0 × 10−5 | |
Ampicillinb | 50 mM NaH2PO4, pH 7.4 | 0.00023±0.00001 | ND | ND |
100 mM NaH2PO4, pH 7.4 | 0.00034±0.00001 | ND | ND | |
50 mM Tris-Cl, pH 7.4 | < 4.0 × 10−5 | ND | ND | |
50 mM NaH2PO4, 9 mM Na acetate, pH 7.4 | 0.0056 ± 0.0004 | < 4.0 × 10−5 | < 4.0 × 10−5 | |
50 mM NaH2PO4, 9 mM Na propanoate, pH 7.4 | 0.0096 ± 0.0006 | < 4.0 × 10−5 | < 4.0 × 10−5 |
Measured by SDS-PAGE assay.
Measured by competition with Cibacron Blue 3GA. ND – not determined