start-ver=1.4
cd-journal=joma
no-vol=54
cd-vols=
no-issue=4
article-no=
start-page=389
end-page=398
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2019
dt-pub=20190816
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Characterization of the channel-pores formed by Bacillus thuringiensis Cry46Ab toxin in planar lipid bilayers
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract= Cry46Ab from Bacillus thuringiensis TK-E6 is a new mosquitocidal toxin with aerolysin-type architecture, and has been shown that co-administration of Cry46Ab with other mosquitocidal Cry toxins results in synergistic toxicity against Culex pipiens Coquillett (Diptera: Culicidae) mosquito larvae. Cry46Ab, therefore, is expected to find use in improving the insecticidal activity of B. thuringiensis-based bioinsecticides. In the present study, the mode of action of Cry46Ab was explored by single-channel measurements of Cry46Ab channel-pores. The single-channel conductances of channel-pores formed in planar lipid bilayers by Cry46Ab were determined to be 31.8 +/- 2.7 pS in 150 mM NaCl and 24.2 +/- 0.7 pS in 150 mM CaCl2. Ion-selectivity measurements revealed that the channel-pores formed by Cry46Ab were cation selective. The permeability ratio of K+ to Cl-was approximately 4, and the preferences for cations were K+ > Na+, K+ > Ca2+, and Ca2+ > Na+. A calcein release assay using liposomes suggested that Cry46Ab influences the integrity of membrane vesicles. Formation of cation-selective channel-pores has been observed with other insecticidal Cry toxins that have structures distinct from those of Cry46Ab; the capability of forming such pores may be a property required of insecticidal toxins.
en-copyright=
kn-copyright=

en-aut-name=SakakibaraAkira
en-aut-sei=Sakakibara
en-aut-mei=Akira
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=TakebeSo
en-aut-sei=Takebe
en-aut-mei=So
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=IdeToru
en-aut-sei=Ide
en-aut-mei=Toru
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=HayakawaTohru
en-aut-sei=Hayakawa
en-aut-mei=Tohru
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

affil-num=1
en-affil=Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University
kn-affil=

affil-num=2
en-affil=Graduate School of Biology-Oriented Science and Technology, Kindai University
kn-affil=

affil-num=3
en-affil=Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University
kn-affil=

affil-num=4
en-affil=Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University
kn-affil=
en-keyword=Bacillus thuringiensis
kn-keyword=Bacillus thuringiensis
en-keyword=Cry46Ab toxin
kn-keyword=Cry46Ab toxin
en-keyword=Planar lipid bilayer
kn-keyword=Planar lipid bilayer
en-keyword=Single-channel analysis
kn-keyword=Single-channel analysis
en-keyword=Calcein release assay
kn-keyword=Calcein release assay
END