The toxic A-chain of mistletoe lectin I: isolation and its effect on cell-free protein synthesis.

The reduction of Sepharose bound mistletoe lectin I (ML I) is a convenient method for preparing A- and B-chains under mild conditions. The B-chain represents the D-galactose binding moiety. The A-chain shows a significant dose-dependent inhibition of protein synthesis in cell-free systems from rat liver and rabbit reticulocytes, while pure B-chain preparations do not affect ribosomal translation processes.