title: Phospholipase C produced by Clostridium botulinum types C and D: comparison of gene, enzymatic, and biological activities with those of Clostridium perfringens alpha-toxin.
abstract: Clostridium botulinum type C and D strains recently have been found to produce PLC on egg yolk agar plates. To characterize the gene, enzymatic and biological activities of C. botulinum PLCs (Cb-PLCs), the cb-plc genes from 8 strains were sequenced, and 1 representative gene was cloned and expressed as a recombinant protein. The enzymatic and hemolytic activities of the recombinant Cb-PLC were measured and compared with those of the Clostridium perfringens alpha-toxin. Each of the eight cb-plc genes encoded a 399 amino acid residue protein preceded by a 27 residue signal peptide. The protein consists of 2 domains, the N- and C-domains, and the overall amino acid sequence identity between Cb-PLC and alpha-toxin was greater than 50%, suggesting that Cb-PLC is homologous to the alpha-toxin. The key residues in the N-domain were conserved, whereas those in the C-domain which are important in membrane interaction were different than in the alpha-toxin. As expected, Cb-PLC could hydrolyze egg yolk phospholipid, p-nitrophenylphosphorylcholine, and sphingomyelin, and also exhibited hemolytic activity;however, its activities were about 4- to over 200-fold lower than those of alpha-toxin. Although Cb-PLC showed weak enzymatic and biological activities, it is speculated that Cb-PLC might play a role in the pathogenicity of botulism or for bacterial survival.
authors: Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
authors: Ni Nengah Dwi
authors: NN
authors: Fatmawati
authors: Yoshihiko
authors: Y
authors: Sakaguchi
authors: Tomonori
authors: T
authors: Suzuki
authors: Masataka
authors: M
authors: Oda
authors: Kenta
authors: K
authors: Shimizu
authors: Yumiko
authors: Y
authors: Yamamoto
authors: Jun
authors: J
authors: Sakurai
authors: Osamu
authors: O
authors: Matsushita
authors: Keiji
authors: K
authors: Oguma
mesh_terms: D000595:Amino Acid Sequence; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity; D047968:Clostridium botulinum type C / Q000201:enzymology*; D047969:Clostridium botulinum type D / Q000201:enzymology*; D008969:Molecular Sequence Data; D010738:Type C Phospholipases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity
chemical_list: D001427:Bacterial Toxins; D002135:Calcium-Binding Proteins; D010738:Type C Phospholipases; C040649:alpha toxin, Clostridium perfringens