title: Purification and properties of a novel insecticidal protein from the locust pathogen Serratia marcescens HR-3.
abstract: One or more proteinaceous factors with insecticidal activities in the locust pathogen Serratia marcescens HR-3 culture filtrates were found to cause the death of grassland locusts. A novel insecticidal protein was purified to homogeneity. It was a monomer of 61 kDa. The purified protein showed a strong insecticidal effect with a median lethal dosage of 12.1 microg locust(-1) and contained a high level of protease activity (101 U ml(-1)). Insecticidal activity was significantly decreased when the protein was pretreated with ethylene diamine tetraacetic acid and 1-10-phenanthroline, and it was restored when the treated protein was incubated with Zn(2+). The N-terminal amino acid sequence of insecticidal protein showed sequence similarity with metalloprotease from S. marcescens SM6 and Serratia spp. E15. Our results suggested that the factor primarily responsible for insecticidal activity toward locusts was a zinc-dependent 61-kDa metalloprotease.
authors.affiliation: National Laboratory of Grassland Biocontrol Engineering, College of Life Science, Sichuan University, Chengdu 610064, People's Republic of China.
authors.forename: Ke
authors.initials: K
authors.lastname: Tao
authors.forename: Zhangfu
authors.initials: Z
authors.lastname: Long
authors.forename: Kun
authors.initials: K
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Tao
authors.forename: Shigui
authors.initials: S
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D002614:Chelating Agents / Q000494:pharmacology; D003067:Coenzymes / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D006110:Grasshoppers / Q000187:drug effects; D007306:Insecticides / Q000302:isolation & purification* / Q000494:pharmacology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000302:isolation & purification* / Q000378:metabolism; D010618:Phenanthrolines / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D012706:Serratia marcescens / Q000737:chemistry*; D015032:Zinc / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D002614:Chelating Agents; D003067:Coenzymes; D007306:Insecticides; D010618:Phenanthrolines; D004492:Edetic Acid; D010447:Peptide Hydrolases; D015032:Zinc; C025205:1,10-phenanthroline