The secondary structure of the insect defensin A depends on its environment. A circular dichroism study.

Abstract : Defensin A is an inducible antibacterial protein isolated from the larvae of Phormia terranovae. The conformation of defensin A has been previously determined by two-dimensional 1H-NMR for concentrations in the range of 4-8 mM in water (Bonmatin JM et al (1992) J Biomol NMR 2, 235-256). CD spectroscopic data of defensin A at lower concentrations (10(-5) to 10(-3) M) are reported herein. The ellipticity in the 200-240 nm wavelength range for various solvents varies as follows: acetonitrile < water < methanol < HFIP. The magnitude of theta 222 is strongly dependent on defensin concentration in a buffer solution, suggesting an aggregation process. The helical content of defensin A is maximum at a pH value range (7.5-8) for which the optimum antibacterial activity was observed (Cociancich S et al (1993) J Biol Chem 268, 19239-19245).
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Submitted on : Thursday, March 28, 2019 - 12:31:39 PM
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  • HAL Id : hal-02082593, version 1
  • PUBMED : 8589051

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M Maget-Dana, J.M Bonmatin, C Hetru, M. Ptak, J Maurizot. The secondary structure of the insect defensin A depends on its environment. A circular dichroism study.. Biochimie, Elsevier, 1995, 77 (4), pp.240-4. ⟨hal-02082593⟩

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