PubMed · 2026-06-29
Computer simulations show that brassinolide, a plant growth hormone structurally similar to animal cholesterol, crosses the plasma membrane via a thermodynamically distinct route compared to common plant sterols. The findings clarify how these hormones reach the protein pumps that export them from the cell, advancing understanding of a process essential to plant development.
All-atom molecular dynamics simulations revealed thermodynamic differences between brassinolide and β-sitosterol passive transport across an asymmetric plant plasma membrane.
The simulations identified a specific diffusion pathway by which brassinolide becomes exposed to the entry sites of the ABCB1 and ABCB19 transporter proteins.
Brassinolide distributes asymmetrically between the disordered inner membrane leaflet and the tightly packed, sphingolipid-rich outer leaflet, a pattern distinct from β-sitosterol.