KN-93 (10 µM) delayed NaV1.5 recovery from inactivation in a HEK-derived expression system. The separate AIP comparison did not reproduce the effect, supporting a CaMKII-independent component and limiting attribution of KN-93 responses solely to kinase inhibition. [1]
KN-93 inhibited IKr tail current in isolated rabbit ventricular myocytes (IC50 102.57 ± 9.28 nM; mean ± SEM, n=6 cells). A 1 µM exposure also abolished the guinea-pig tail current. These results identify an ion-channel effect relevant to interpreting cardiac experiments; the paper does not specify the tested salt form. [2]
KN-93 slows calcium dissociation from calmodulin
Biochemical assay · Purified human calmodulin; Quin-2 stopped-flow calcium-dissociation assay at 4 °C [1]
KN-93 slowed both calcium-release components. Dose-response EC50 values describe this kinetic effect, not kinase inhibition or binding Kd. Four individual titrations were collected; reported EC50 values are average ± SD. TFP was an assay comparator; KN-93-free calmodulin provided baseline.
Literature-Reported Treatment Conditions
- Treatment concentration
- KN-93 concentration series (Figure 2b); 3.0 µM CaM, 30 µM CaCl2 in stated solution
- Exposure duration
- Rapid-mixing kinetic recording; no pretreatment interval specified
- Method
- Quin-2 stopped-flow fluorescence, 4 °C; 10 mM Tris pH 7.0, 150 mM KCl
- Vehicle
- DMSO (KN93 stock solvent)
- Co-treatment
- TFP tested separately as a comparator; not a KN-93 combination
- Reported limits
- Exact full series concentrations and individual replicate rows were not extracted; supplementary table not retrieved.
Methods and source locations
Compound reported in the paper: KN-93; Compound label in the paper: KN93
Results describe the paper-tested KN-93 material and stated model only; no conversion among salts or Adooq lot equivalence is assumed.
Results 2.2; Figure 2b; Methods 4.2–4.3
Slowing of fast Ca2+ dissociation component, attributed to CaM N-domain: Dose-response fit of Ca2+ release rates; at least two traces averaged per individual rate. — Results 2.2; Figure 2b; Methods 4.3
Slowing of slow Ca2+ dissociation component, attributed to CaM C-domain: Same stopped-flow series; EC50 is an effect concentration, not a dissociation constant. — Results 2.2; Figure 2b; Methods 4.3
KN-93 delays NaV1.5 recovery from inactivation
Cell-based study · Human wild-type NaV1.5 expressed in a HEK-derived cell system (tsA201 in §4.5; HEK293T in §4.6) [1]
10 µM KN93 increased the time constant for recovery from fast inactivation versus DMSO. The separate 1 µM AIP comparison did not change recovery or inactivation kinetics, supporting a CaMKII-independent component under these conditions. KN93 and AIP were separate treatment groups.
Literature-Reported Treatment Conditions
- Treatment concentration
- 10 µM KN93; separate 1 µM AIP control comparison
- Exposure duration
- Measurements 5 minutes after cell rupture; 24–48 hours after transfection
- Method
- Whole-cell patch clamp at room temperature; paired-pulse recovery protocol
- Vehicle
- DMSO control
- Co-treatment
- AIP tested separately, not co-administered with KN93
- Reported limits
- KN93 pretreatment duration and final DMSO percentage not specified in the read electrophysiology methods.
Methods and source locations
Compound reported in the paper: KN-93; Compound label in the paper: KN93
Results describe the paper-tested KN-93 material and stated model only; no conversion among salts or Adooq lot equivalence is assumed.
Results 2.4; Figure 4a,c and caption; Methods 4.5–4.6
Recovery from fast inactivation: Mono-exponential fit; exact tau from caption; n from viewed Figure 4a. See private review for mislabeled time axis. — Figure 4a/caption; Methods 4.6
Recovery and inactivation kinetics with peptide inhibitor AIP: Separate whole-cell recordings; n transcribed from viewed panels c–d. — Results 2.4; Figure 4c–d; Methods 4.6
Concentration-dependent IKr inhibition in isolated ventricular myocytes
Cell-based study · Freshly isolated New Zealand White rabbit ventricular myocytes; guinea-pig ventricular myocytes as a cross-species check [2]
KN-93 inhibited rabbit IKr tail current with nanomolar IC50. Inhibition developed within 1 minute; 1 µM abolished the tail current, with no residual E-4031-sensitive component. Guinea-pig tail current was also abolished at 1 µM. These isolated-cell experiments are not in-vivo dosing studies.
Literature-Reported Treatment Conditions
- Treatment concentration
- 10–1000 nM KN-93 in rabbit series; 1 µM in guinea-pig check
- Exposure duration
- Inhibition developed within 1 minute at each concentration tested
- Method
- Bath application during conventional voltage clamp at 36 ± 0.1 °C; 10 mM BAPTA in pipette
- Vehicle
- Vehicle not specified in read Methods
- Co-treatment
- 1 µM HMR-1556 and 10 µM nifedipine suppressed IKs and ICa,L; E-4031 used to identify residual IKr
- Reported limits
- Counterion, catalog/lot and vehicle not specified; no salt-specific or Adooq-lot potency inference.
Methods and source locations
Compound reported in the paper: KN-93; Compound label in the paper: KN-93
Results describe the paper-tested KN-93 material and stated model only; no conversion among salts or Adooq lot equivalence is assumed.
Results 3.2; Figure 2A–E and caption; Methods 2–2.3
Rabbit IKr tail-current inhibition: Concentration-response fit; +40 mV activating pulse from −40 mV holding potential; exact value from text and viewed figure label. — Results 3.2; Figure 2C; Methods 2.3
Guinea-pig IKr tail current: Conventional voltage clamp with species-adapted command; not a second dose-response estimate. — Results 3.2; Figure 2E and caption
