title: ADP-ribosylation of a 21-24 kDa eukaryotic protein(s) by C3, a novel botulinum ADP-ribosyltransferase, is regulated by guanine nucleotide.
abstract: Besides botulinum C2 toxin, Clostridium botulinum type C produces another ADP-ribosyltransferase, which we termed 'C3'. ADP-ribosyltransferase C3 has a molecular mass of 25 kDa and modifies 21-24 kDa protein(s) in platelet and brain membranes. C3 was about 1000 times more potent than botulinum C1 toxin in ADP-ribosylation of membrane proteins. C3-catalysed ADP-ribosylation of the 21-24 kDa protein(s) was decreased by stable guanosine triphosphates, with the potency order GTP[S] much greater than p[NH]ppG greater than p[CH2]ppG. GTP[S] inhibited the ADP-ribosylation caused by C3 by maximally 70-80%, with half-maximal and maximal effects occurring at 0.3 and 10 microM-GTP[S] respectively. The concomitant addition of GTP decreased the inhibitory effect of GTP[S]. GTP[S]-induced inhibition of ADP-ribosylation was resistant to washing of pretreated platelet membranes. The data suggest that the novel botulinum ADP-ribosyltransferase C3 modifies eukaryotic 21-24 kDa guanine nucleotide-binding protein(s).
mesh_terms: D036002:ADP Ribose Transferases; D000246:Adenosine Diphosphate Ribose / Q000097:blood / Q000378:metabolism*; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D001798:Blood Proteins; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003014:Clostridium botulinum / Q000201:enzymology; D006150:Guanine Nucleotides / Q000494:pharmacology*; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D006801:Humans; D008565:Membrane Proteins / Q000097:blood / Q000378:metabolism*; D010430:Pentosyltransferases / Q000097:blood*; D013873:Thionucleotides / Q000494:pharmacology; D014121:Toxoids / Q000494:pharmacology
chemical_list: D001798:Blood Proteins; C035415:Clostridium botulinum toxoid; D006150:Guanine Nucleotides; D008565:Membrane Proteins; D013873:Thionucleotides; D014121:Toxoids; D000246:Adenosine Diphosphate Ribose; C011265:guanosine 5'-(beta,gamma-methylene)triphosphate; D006165:Guanylyl Imidodiphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D036002:ADP Ribose Transferases; D010430:Pentosyltransferases