title: Purification and functional characterization of insecticidal sphingomyelinase C produced by Bacillus cereus.
abstract: Bacillus cereus isolated from the larvae of Myrmeleon bore was found to secrete proteins that paralyze and kill German cockroaches, Blattela germanica, when injected. One of these active proteins was purified from the culture broth of B. cereus using anion-exchange and gel-filtration chromatography. The purified toxin, with a molecular mass of 34 kDa, was identified as sphingomyelinase C (EC 3.1.4.12) on the basis of its N-terminal and internal amino-acid sequences. A recombinant sphingomyelinase C expressed in Escherichia coli was as potent as the native protein in killing the cockroaches. Site-directed mutagenesis (His151Ala) that inactivated the sphingomyelinase activity also abolished the insecticidal activity, suggesting that the rapid insect toxicity of sphingomyelinase C results from its phospholipid-degrading activity.
authors.affiliation: Department of Agricultural Chemistry, Faculty of Agriculture, Kinki University, Nara, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Nishiwaki
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ito
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Otsuki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Koichiro
authors.initials: K
authors.lastname: Komai
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Matsuda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001409:Bacillus cereus / Q000201:enzymology*; D001483:Base Sequence; D003001:Cloning, Molecular; D003058:Cockroaches; D004269:DNA, Bacterial; D004926:Escherichia coli / Q000235:genetics; D007306:Insecticides / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D013108:Sphingomyelin Phosphodiesterase / Q000096:biosynthesis / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D007306:Insecticides; D013108:Sphingomyelin Phosphodiesterase