Selective Activation of a TRPC6 Ion Channel Over TRPC3 by Metalated Type-B Polycyclic Polyprenylated Acylphloroglucinols

J Med Chem. 2023 Nov 23;66(22):15061-15072. doi: 10.1021/acs.jmedchem.3c01170. Epub 2023 Nov 3.

Abstract

Selective modulation of TRPC6 ion channels is a promising therapeutic approach for neurodegenerative diseases and depression. A significant advancement showcases the selective activation of TRPC6 through metalated type-B PPAP, termed PPAP53. This success stems from PPAP53's 1,3-diketone motif facilitating metal coordination. PPAP53 is water-soluble and as potent as hyperforin, the gold standard in this field. In contrast to type-A, type-B PPAPs offer advantages such as gram-scale synthesis, easy derivatization, and long-term stability. Our investigations reveal PPAP53 selectively binding to the C-terminus of TRPC6. Although cryoelectron microscopy has resolved the majority of the TRPC6 structure, the binding site in the C-terminus remained unresolved. To address this issue, we employed state-of-the-art artificial-intelligence-based protein structure prediction algorithms to predict the missing region. Our computational results, validated against experimental data, indicate that PPAP53 binds to the 777LLKL780-region of the C-terminus, thus providing critical insights into the binding mechanism of PPAP53.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Cryoelectron Microscopy
  • Ketones / chemistry
  • Ketones / pharmacology
  • Phloroglucinol / pharmacology
  • Polycyclic Compounds / pharmacology
  • Spiro Compounds / chemistry
  • Spiro Compounds / pharmacology
  • TRPC Cation Channels* / drug effects
  • TRPC Cation Channels* / metabolism
  • TRPC6 Cation Channel / drug effects

Substances

  • Phloroglucinol
  • Polycyclic Compounds
  • TRPC Cation Channels
  • TRPC3 cation channel
  • TRPC6 Cation Channel
  • PPAP53
  • Ketones
  • Spiro Compounds