Shunji Natori

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To compare the effects of cytochalasins on the cellular level with those on the molecular level, 24 cytochalasins, 20 natural compounds and 4 derivatives, were used. The following effects were tested for each of 24 cytochalasins; (a) four high dose (2-20 muM) effects on the cellular level: rounding up of fibroblastic cells, contraction of actin cables,(More)
The action mechanism of sapecin, an antibacterial peptide with membrane permeabilization activity, was investigated. The dose dependence of the membrane permeabilization caused by sapecin was sigmoidal, suggesting that sapecin oligomerization leads to the membrane permeabilization. Solution nuclear magnetic resonance analysis of the sapecin-phospholipid(More)
Previously, we identified two proteins with molecular masses of 200 and 210 kDa in basement membranes of Sarcophaga imaginal discs as substrates for cathepsin L [Homma, K. and Natori, S. (1996) Eur. J. Biochem. 240, 443-447]. Here we demonstrated that the same proteins were also present in the basement membranes of larval brains. These proteins were(More)
Two insect defencins, sapecin and sapecin B, were chemically synthesized to confirm their structure and antibacterial activity and also to examine the possibility that these peptides bind to the same site on the large conductance calcium-activated potassium channel as charybdotoxin. Both synthetic peptides showed the same antibacterial activity as native(More)
Pricking the body wall of Sarcophaga peregrina (flesh fly) larvae with a needle activated the immune system of this insect and induced various immune molecules, including antibacterial proteins, in the hemolymph. In this review, I summarize and discuss the functions of these immune molecules, with particular emphasis on the dual roles of some of these(More)
Proliferation and apoptosis of neural cells were found to be induced simultaneously when larval brains of Sarcophaga peregrina were cultured in the presence of 20-hydroxyecdysone (20-HE) for 24 h. The locations of proliferating cells and apoptotic cells in the brain hemispheres were different. The morphology of brains exposed to 20-HE for a short period(More)
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