mistletoe lectin I

Mistletoe lectin I (ML-1), also known as viscumin or Viscum album agglutinin (VAA), is a biologically active protein isolated from the European mistletoe plant (Viscum album). It is a type II ribosome-inactivating protein composed of two chains: an A-chain with RNA N-glycosidase activity that depurinates 28S rRNA and inhibits protein synthesis (cytotoxic effect), and a B-chain that binds specifically to beta-galactoside residues on cell surfaces. The B-chain facilitates cellular uptake by binding to galactose-containing glycoligands. ML-1 has demonstrated both cytotoxic and immunomodulatory properties in preclinical studies. It can stimulate cytokine secretion by immune cells, increase natural killer cell numbers and activity, enhance macrophage function, and modulate T-cell responses. Mistletoe extracts standardized for ML-1 are used as biological response modifiers in integrative oncology settings; however, robust clinical evidence for antitumor efficacy remains limited[2][5][6][7][8].

Other names

galactoside-specific lectin from mistletoebeta-galactoside-specific lectin 1Viscum album agglutiningalactoside-specific mistletoe lectin