Atorvastatin, a commonly prescribed statin, works by inhibiting the enzyme HMG-CoA reductase, which plays a central role in cholesterol production in the liver. However, its mechanism of action also involves direct binding to certain receptors.

Atorvastatin has been shown to bind directly to the nuclear pregnane X receptor (PXR), a nuclear receptor involved in the regulation of CYP3A4 and other enzymes involved in cholesterol biosynthesis. This binding activity may contribute to the drug's cholesterol-lowering effects [1].

Additionally, atorvastatin has been found to bind to the liver X receptor (LXR), a nuclear receptor that regulates the expression of genes involved in cholesterol efflux and transport [2]. The binding of atorvastatin to LXR may also contribute to its cholesterol-lowering effects by promoting the removal of excess cholesterol from the bloodstream.

It's worth noting that atorvastatin's binding activity to these receptors is just one aspect of its complex mechanism of action, which also involves inhibition of HMG-CoA reductase and modulation of other cellular processes.

Sources:

[1] https://www.drugpatentwatch.com/drug/Atorvastatin/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3413578/

Sources cited:

1. DrugPatentWatch.com (Atorvastatin)
2. PMC (Pregnane X receptor and liver X receptor)