Hi,
I noticed very peculiar values in ChEMBL database related to type Percent Effect.
I am talking e.g. about compound CHEMBL3450662, where the value of Percent Effect ranges (based on target) from approx. -4300% to 95%. I understand the value of percentage could in principle be negative (e.g. as a difference) but I would like to know its meaning in this context.
Does anyone have any experience with Percent Effect measurements?
Thank you.
Negative % effect for an inhibitor means that the supposed inhibitor increased the activity rather than decreasing it. A receptor agonist would be an example. In the example, -4300% effect would mean a 43-fold enhancement of activity.
On the other hand, it could mean that the substance interfered badly in the assay. For example, suppose the assay measures the light absorbance of an enzyme product. Inhibition of the enzyme results in less product formation, hence a lower absorbance. But if the test substance absorbs light at the same wavelength as the product, it will appear to increase the activity of the enzyme, even if it has no effect on the enzyme activity. This type of interference (and other types) is very common when screening libraries of compounds.
Sorry for the delay in answering
As such I have no experience on that topic, it's just the data we collected in the research.
Thank you for the response. I suspected that the negative values could be explained like that (both cases). Since there is no additional data available, it is impossible to decide which one is more probable here.
The term "Percent Effect" in pharmacology typically refers to the percentage change in a biological response elicited by a drug or compound, relative to a control condition. It is commonly used in dose-response studies to quantify the potency and efficacy of a drug or compound.
In the ChEMBL database, Percent Effect values are often reported as a measure of the effect of a drug or compound on a specific biological target, such as a receptor or enzyme. The values can be positive, negative, or zero, depending on the nature and direction of the effect.
Negative Percent Effect values can occur when a drug or compound has an inhibitory effect on a target, resulting in a decrease in the biological response compared to the control condition. In the case of CHEMBL3450662, the negative values you observed could indicate that the compound has an inhibitory effect on the target in question.
Positive Percent Effect values, on the other hand, can occur when a drug or compound has a stimulatory effect on a target, resulting in an increase in the biological response compared to the control condition. Zero Percent Effect values indicate that the drug or compound has no effect on the target.
It is worth noting that Percent Effect values are often normalized to a reference compound or standard, which can influence the absolute values reported in the database. Additionally, the specific experimental conditions and assay protocols used to generate the data can also affect the reported Percent Effect values. Therefore, it is important to carefully evaluate the experimental details and interpretation of the data when using Percent Effect values from the ChEMBL database or any other source.
- Badges
- Science topic
- Similar topics
- Engineering
- Computer Engineering
- Computer