E-4031: Selective hERG Potassium Channel Blocker in Cardiac Research

Executive Summary: E-4031 is a potent and selective hERG potassium channel blocker (IC50: 7.7 nM) used to model arrhythmogenic risk in cardiac electrophysiology research (source: product_spec). In vitro, it induces early afterdepolarizations and torsades de pointes (TdP), prolongs action potential duration, and depolarizes the maximum diastolic potential (source: paper). E-4031 is instrumental in 3D cardiac organoid assays using shell microelectrode arrays for high-content, spatiotemporal electrophysiological mapping. The compound is supplied by APExBIO with high purity (≥98%), validated by HPLC and NMR (source: product_spec). It remains a research-use-only tool for preclinical modeling of cardiac safety and arrhythmia mechanisms.

Biological Rationale

ATP-sensitive potassium channels (K_ATP) are distributed across muscle, pancreatic beta cells, and neural tissues, tightly linking cellular metabolism to membrane excitability via nucleotide modulation (source: product_spec). The human Ether-à-go-go-Related Gene (hERG) encodes the rapid delayed rectifier potassium current (I_Kr), a critical determinant of cardiac repolarization. Defects or pharmacological block of hERG channels are primary contributors to long QT syndrome and arrhythmia risk. Selective inhibition of this channel in controlled settings enables mechanistic dissection of action potential dynamics and arrhythmogenic triggers, a necessity for cardiac safety pharmacology and translational cardiac electrophysiology research (source: paper).

Mechanism of Action of E-4031

E-4031, chemically N-(4-(1-(2-(6-methylpyridin-2-yl)ethyl)piperidine-4-carbonyl)phenyl)methanesulfonamide, selectively blocks hERG channels at nanomolar concentrations (IC50 = 7.7 nM) (source: product_spec). By inhibiting I_Kr, E-4031 prolongs the cardiac action potential duration and delays repolarization. This action increases the risk of early afterdepolarizations (EADs) and torsades de pointes (TdP), especially in models with bradycardic conditions or structural cardiac heterogeneity (source: paper). E-4031 also reduces upstroke velocity and diastolic depolarization rates, creating a robust proarrhythmic substrate for preclinical investigation.

Evidence & Benchmarks

• E-4031 blocks hERG/I_Kr channels with an IC50 of 7.7 nM in validated in vitro assays (source: product_spec).
• Induces early afterdepolarizations and torsades de pointes in multicellular cardiac preparations (source: paper).
• Prolongs action potential duration and QT interval in both 2D and 3D cardiac organoid models (source: paper).
• Enables mechanistic study of repolarization gradients and arrhythmia genesis using shell microelectrode arrays (source: paper).
• Validated to a minimum purity of ≥98% by HPLC and NMR (source: product_spec).

Compared with E-4031 and the Future of Cardiac Electrophysiology, this article provides updated, direct evidence from 3D organoid models using shell MEAs, clarifying spatiotemporal mapping advances. The related article E-4031 (SKU B6077): Precision hERG Blockade for Cardiac E... focuses on protocol reliability and workflow recommendations, while the current review enumerates peer-reviewed, quantitative benchmarks. For a translational perspective, E-4031: Precision hERG Blockade for 3D Cardiac Models discusses regulatory-relevant arrhythmia modeling; this article supplements those insights with new technical performance data.

Applications, Limits & Misconceptions

E-4031 is primarily used for:

• Cardiac safety pharmacology and arrhythmia risk modeling.
• Mechanistic studies of QT interval prolongation and proarrhythmic substrate formation.
• High-content 3D electrophysiological mapping with shell MEAs in cardiac organoids (source: paper).
• Validating drug-induced arrhythmia mechanisms and screening antiarrhythmic agents in preclinical settings.

Common Pitfalls or Misconceptions

• E-4031 is not a pan-ATP-sensitive potassium channel blocker; its effect is highly selective for hERG/I_Kr (source: product_spec).
• Results in rodent or 2D cell models may not fully predict human clinical outcomes due to species- and dimensionality-specific electrophysiological differences (source: paper).
• E-4031 cannot be used for therapeutic purposes; it is strictly for research applications and remains in the preclinical stage (source: product_spec).
• The compound is insoluble in water; improper solvent selection can result in failed assays (source: product_spec).
• Long-term solution stability is not guaranteed; short-term use and storage at -20°C are required (source: product_spec).

Workflow Integration & Parameters

Protocol Parameters

• assay | IC50 = 7.7 nM | in vitro hERG/I_Kr patch clamp | Defines minimum effective concentration for channel block | product_spec
• solubility | ≥103 mg/mL (DMSO, 25°C, ultrasonic) | solution prep | Enables high stock concentrations for titration | product_spec
• solubility | ≥9.66 mg/mL (ethanol, 25°C, warming, ultrasonic) | alternative solution prep | Useful when DMSO is not suitable | product_spec
• storage | -20°C | all applications | Prevents degradation; maintains purity | product_spec
• working solution | short-term use only | cell/tissue assays | Prevents loss of potency in extended studies | workflow_recommendation

Conclusion & Outlook

E-4031, as supplied by APExBIO, is a benchmark tool for the selective blockade of hERG potassium channels in cardiac electrophysiology research. Its proven efficacy in 3D cardiac organoid models—enabled by advanced shell microelectrode array technology—allows precise mapping of proarrhythmic substrates and QT interval prolongation (source: paper). While not suitable for clinical use, E-4031 remains indispensable for translational research, safety pharmacology, and high-content mechanistic assays. Future advances in organoid technology and bioelectronic interfaces will likely build upon the robust benchmarks established by E-4031 research, supporting regulatory science and drug discovery efforts.

For detailed specifications, purity data, and ordering, refer to the E-4031 product page.