| Autor: |
Cummings CE; Department of Biochemistry, University of Cambridge, UK., Armstrong G, Hodgman TC, Ellar DJ |
| Jazyk: |
angličtina |
| Zdroj: |
Molecular membrane biology [Mol Membr Biol] 1994 Apr-Jun; Vol. 11 (2), pp. 87-92. |
| DOI: |
10.3109/09687689409162225 |
| Abstrakt: |
In order to study the mechanism of action of Bacillus thuringiensis delta-endotoxins, a synthetic 31-mer peptide corresponding to the sequence of a putative pore-forming segment of the CrylA(c) toxin was characterized structurally and functionally. The peptide maps onto the central helix (alpha 5) of the six-helix bundle of domain I of the crystal structure of the CryIIIA toxin. CD and NMR spectroscopic studies indicated that the peptide exists as an alpha-helix in methanol and a random coil in water. The peptide associated with liposomes at pH 4.7 and formed discrete, characterizable channels in planar lipid bilayers at low pHs. These channels had a conductance value of 60 picosiemens (pS). It is possible that this helix is a component of the transmembrane pore formed by B. thuringiensis delta-endotoxins in vivo. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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