cyclosporin A binding

Definition

Target type: molecularfunction

Binding to cyclosporin A, a cyclic undecapeptide that contains several N-methylated and unusual amino acids. [GOC:mb]

Cyclosporin A (CsA) is a potent immunosuppressant drug that binds to the immunophilin cyclophilin A (CypA) with high affinity. This interaction inhibits the activity of calcineurin, a phosphatase that plays a crucial role in T cell activation.

CsA-CypA complex binds to calcineurin, blocking its dephosphorylation activity. Calcineurin normally dephosphorylates the nuclear factor of activated T cells (NFAT), allowing it to translocate to the nucleus and initiate transcription of genes involved in T cell activation, including cytokine production.

By inhibiting calcineurin, CsA prevents NFAT activation and thereby suppresses T cell activation, proliferation, and cytokine production. This immunosuppressive effect is critical for preventing rejection of transplanted organs and autoimmune disorders.

The binding of CsA to CypA is a highly specific and selective process. CsA interacts with a hydrophobic pocket within CypA, forming a stable complex. This interaction is mediated by a combination of hydrogen bonds, van der Waals forces, and hydrophobic interactions.

The molecular mechanism of CsA binding to CypA and its subsequent inhibition of calcineurin is a complex interplay of protein-protein interactions and conformational changes. This intricate process highlights the importance of understanding the molecular basis of drug action for developing targeted therapies.

In summary, CsA binds to CypA, preventing its interaction with calcineurin. This inhibition of calcineurin activity leads to the suppression of T cell activation and subsequent immunosuppressive effects. The binding mechanism involves specific interactions within a hydrophobic pocket of CypA, highlighting the crucial role of molecular interactions in drug action.'
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Proteins (6)

Compounds (13)