Evidence that membrane phospholipids and protein are required for binding of diphtheria toxin in Vero cells.
Treatment with phospholipase C strongly protected monkey kidney (Vero) cells against diphtheria toxin and reduced the ability of the cells to bind 125I-labelled toxin. Treatment with phospholipase D and with trypsin also protected the cells, although to a lesser extent. Phospholipase A2 had no protective effect. Phospholipase C also protected fetal hamster kidney cells against the toxin. After removal of the enzymes, as well as after treatment of the cells with 4-acetamide 4'-isothiocyanostilbene 2,2'-disulfonic acid, diphtheria toxin binding capability was restored slowly, apparently by a process requiring protein synthesis, since cycloheximide blocked the restoration. The data indicate that both phospholipids and protein are involved in the binding sites for diphtheria toxin.
D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D003513:Cycloheximide / Q000494:pharmacology; D004167:Diphtheria Toxin / Q000378:metabolism*; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D007668:Kidney; D007700:Kinetics; D008563:Membrane Lipids / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D010740:Phospholipases / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism*; D011956:Receptors, Cell Surface; D011950:Receptors, Cholinergic / Q000187:drug effects / Q000378:metabolism*; D014357:Trypsin / Q000494:pharmacology
D004167:Diphtheria Toxin; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D008563:Membrane Lipids; D008565:Membrane Proteins; D010743:Phospholipids; D011956:Receptors, Cell Surface; D011950:Receptors, Cholinergic; D003513:Cycloheximide; D010740:Phospholipases; D014357:Trypsin