Actin Sequestration, Explained

Thymosin beta-4 is the most abundant G-actin binding protein in mammalian cells. Actin is the structural protein that lets cells move and change shape. By sequestering monomeric (G-) actin, Tβ4 maintains a ready reserve of building blocks that cells can rapidly polymerize into filaments (F-actin) when they need to migrate — which is exactly what happens during wound healing.

Without this reserve, cells would have to disassemble existing structures to move. With it, they can deploy new filaments on demand. This is why Tβ4 is implicated in cell migration, angiogenesis, and tissue remodeling — it's the supply chain for cellular motility. TB-500 is the synthetic fragment researchers use to study this actin-binding domain.