TB-500 5mg· 5mg

Thymosin beta-4 binds G-actin with high affinity through its central LKKTETQ motif and surrounding residues, sequestering monomeric actin and regulating the dynamic equilibrium between monomeric and filamentous actin. This sequestration activity influences cell motility, cytoskeletal remodeling, and migration responses required for wound repair.

Beyond actin binding, Tbeta4 has been shown to exert additional bioactivities including upregulation of vascular endothelial growth factor (VEGF), induction of laminin-5, and modulation of inflammatory cytokine networks. In endothelial cells, the protein promotes migration and tube formation in Matrigel assays. In cardiomyocyte and epicardial preparations, Tbeta4 has been observed to activate the epicardium and promote progenitor-like phenotypes through a pathway involving PINCH and integrin-linked kinase. The shorter TB-500 fragment retains actin-binding activity and is reported to engage some but not all of the downstream signaling effects of the full-length protein.