What does hERG stand for?
Abstract. The human ether-a-go-go-related gene (hERG) encodes the pore-forming subunit of the rapidly activating delayed rectifier potassium channel (IKr), which is important for cardiac repolarization. Dysfunction of hERG causes long QT syndrome and sudden death, which occur in patients with cardiac ischemia.
What is the KCNQ1 gene?
The KCNQ1 gene belongs to a large family of genes that provide instructions for making potassium channels. These channels, which transport positively charged atoms (ions) of potassium out of cells, play key roles in a cell’s ability to generate and transmit electrical signals.
Why is hERG important?
HERG channels are involved in cardiac action potential repolarization, and reduced function of hERG lengthens ventricular action potentials, prolongs the QT interval in an electrocardiogram, and increases the risk for potentially fatal ventricular arrhythmias.
What is the hERG assay?
What is a hERG assay? A hERG (human Ether-a-go-go Related Gene) assay is a laboratory technique that gauges the activity of the hERG channel protein. How does the hERG assay support cardiac studies? hERG activity manifests as the movement of potassium ions through a pore present in the hERG channel protein.
What causes KCNQ2?
KCNQ2 is caused by a mutation on the KCNQ2 gene, located on chromosome 20. Chromosomes: Chromosomes are located in the nucleus of human cells and carry the genetic information for each individual. Human body cells normally have 46 chromosomes in each cell.
How can I reduce my hERG?
The introduction of triple bonds close to the pyridine moiety is therefore a very efficient strategy to reduce hERG affinity for compounds possessing side chains with more than two bonds.
What is hERG toxicity?
Background: hERG K(+) channels have been recognized as a primary antitarget in safety pharmacology. Their blockade, caused by several drugs with different therapeutic indications, may lead to QT prolongation and, eventually, to potentially fatal arrhythmia, namely torsade de pointes.
What is hERG IC50?
The ratio of the half-maximum inhibitory concentration of the hERG channel (hERG IC50) to the peak serum concentration of unbound drug (Cmax) is used during drug development to screen out chemical entities likely to cause TdP.
Is there a cure for KCNQ2?
There is currently no FDA approved treatment for KCNQ2.
How common is KCNQ2?
KCNQ2 is rare, representing around 10% of patients with epileptic encephalopathy with onset in the first three months of life; however, the incidence of KCNQ2 is approximately 2.8/100,000 live births (or over 3,000 new cases annually worldwide), which is roughly half the number of births of Dravet Syndrome, the most …
How can I reduce my hERG activity?
One of the most commonly used strategies to reduce hERG (human ether-a-go-go) activity in the drug candidates is introduction of a carboxylic acid group. During the optimization of PPARĪ“ modulators, some of the com- pounds containing a carboxylic acid were found to inhibit the hERG channel in a patch clamp assay.
How rare is KCNQ2?
How is KCNQ2 inherited?
In most children with KCNQ2-developmental and epileptic encephalopathy, the pathogenic KCNQ2 variant occurred spontaneously (de novo) and was not inherited from either parent. In rare cases, the pathogenic KCNQ2 variant has been passed on from an asymptomatic parent due to parental mosaicism.
The importance of the hERG ion channel for drug discovery programs stems from the observation that not only mutations, but also drug induced blockade of the channel, may cause repolarization abnormalities.
What is hERG test?
A hERG (human Ether-a-go-go Related Gene) assay is a laboratory technique that gauges the activity of the hERG channel protein. How does the hERG assay support cardiac studies? hERG activity manifests as the movement of potassium ions through a pore present in the hERG channel protein.
What is hERG activity?
This ion channel (sometimes simply denoted as ‘hERG’) is best known for its contribution to the electrical activity of the heart: the hERG channel mediates the repolarizing IKr current in the cardiac action potential, which helps coordinate the heart’s beating.
What are hERG channel blockers?
Introduction: The HERG channel is widely used for the assessment of proarrhythmic risk for new drugs. HERG channel blockers obstruct channel functions through various mechanisms, which usually show time dependence, voltage dependence, and state dependence.
What is hERG inhibitor?
The human ether-a-go-go related gene (hERG) encodes the inward rectifying voltage gated potassium channel in the heart (IKr) which is involved in cardiac repolarisation. Inhibition of the hERG current causes QT interval prolongation resulting in potentially fatal ventricular tachyarrhythmia called Torsade de Pointes.
Introduction of an aliphatic oxygen near to an amine can significantly reduce HERG binding, as can be seen below this can be ascribed to a reduction on the pKa of the basic nitrogen, but also the hydroxyl serves to reduce the overall lipophilicity.
What is the difference between KI and KD?
Ki refers to inhibition constant, while Kd means dissociation constant. Both terms are used to describe the binding affinity that a small molecule or macromolecule has for an enzyme or receptor. The difference is that Kd is a more general, all-encompassing term.
What is Kd pharmacology?
KD is determined experimentally and is a measure of the affinity of a drug for a receptor. More simply, the strength of the ligandāreceptor interaction. To determine KD, a fixed mass of membranes (with receptor) are incubated with increasing concentrations of a radioligand until saturation occurs.