Characterization of mosquito larvicidal parasporal inclusions of a Bacillus thuringiensis serovar higo strain.
The parasporal inclusion proteins of the type strain of Bacillus thuringiensis serovar higo (H44), that have moderate mosquitocidal activity, were characterized. The purified parasporal inclusions, spherical in shape, were examined for activity against the two mosquito species, Culex pipiens molestus and Anopheles stephensi and the moth-fly, Telmatoscopus albipunctatus. The LC50 values of the inclusion for the two mosquitoes were 3.41 and 0.15 microgram.ml-1, respectively. No mortality was shown for T. albipunctatus larvae by the inclusions at concentrations up to 1 mg ml-1. Solubilized parasporal inclusions exhibited no haemolytic activity against sheep erythrocytes. Parasporal inclusions consisted of eight proteins with molecular masses of 98, 91, 71, 63, 59, 50, 44 and 27 kDa. Of these, the 50 and 44 kDa proteins were the major components. Analysis with immunoblotting revealed that, among several inclusion proteins of B. thuringiensis serovar israelensis, only two proteins of 130 kDa and 110 kDa reacted weakly with antibodies against higo proteins. N-terminal amino acid sequences of the 98, 91, and 71 kDa proteins showed 85-100% identity to those of the two established Cry protein classes, Cry4A and Cry10A.
Saitoh
H
H
Section of Applied Microbiology, Fukuoka Industrial Technology Centre, Japan.
Higuchi
K
K
Mizuki
E
E
Hwang
S H
SH
Ohba
M
M
D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000382:microbiology; D001413:Bacillus thuringiensis / Q000737:chemistry / Q000502:physiology*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry* / Q000633:toxicity; D001427:Bacterial Toxins / Q000737:chemistry* / Q000633:toxicity; D015153:Blotting, Western; D003465:Culex / Q000382:microbiology; D004591:Electrophoresis, Polyacrylamide Gel; D004731:Endotoxins / Q000737:chemistry; D006460:Hemolysin Proteins; D002479:Inclusion Bodies / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure; D007814:Larva / Q000382:microbiology; D008969:Molecular Sequence Data; D010572:Pest Control, Biological; D011576:Psychodidae / Q000382:microbiology; D013171:Spores, Bacterial / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis