Botulinum C2 toxin ADP-ribosylates actin

摘要: ADP-ribosylation of regulatory proteins is an important pathological mechanism by which various bacterial toxins affect eukary-otic cell functions. While diphtheria toxin catalyses the elongation factor 2, results in inhibition protein synthesis, cholera and pertussis ADP-ribosylate Ns Ni respectively, GTP-binding components adenylate cyclase system, thereby modulating bidirectional hormonal regulation cyclase1,2Botulinum C2 another has been reported to possess ADP-ribosyltransferase activity3. This extremely toxic agent produced certain strains Clostridium botulinum4 induces hypotension5, increase intestinal secretion6 vascular permeability7 haemorrhaging lungs5. In contrast botulinum neurotoxins, apparently lacks any neurotoxic effects5. Here we report that ADP-ribosylates a relative molecular mass 43,000 (43K) intact cells cell-free preparations. We present evidence 43K substrate actin, mono-AD P-ribosylated toxin. Botulinum also ADP-ribosylated purified liver G-actin, whereas F-actin was only poorly skeletal muscle actin not either its G form or F form. G-actin resulted drastic reduction viscosity polymerized vitro.