Structural Analysis of the Interaction between Jaburetox, an Intrinsically Disordered Protein, and Membrane Models

BROLL, VALQUIRIA; MARTINELLI, ANNE HELENE S.; LOPES, FERNANDA C.; FRUTTERO, LEONARDO L.; ZAMBELLI, BARBARA; SALLADINI, EDOARDO; DOBROVOLSKA, OLENA; CIURLI, STEFANO; CARLINI, CELIA R.

COLLOIDS AND SURFACES B-BIOINTERFACES

ELSEVIER SCIENCE BV

Año: 2017 vol. 159 p. 849 - 849

0927-7765

ack bean urease is entomotoxic to insects with cathepsin-like digestive enzymes, and its toxicity is mainly caused by a polypeptide called Jaburetox (Jbtx), released by cathepsin-dependent hydrolysis of the enzyme. Jbtx is intrinsically disordered in aqueous solution, as shown by CD and NMR. Jbtx is able to alter the permeability of membranes, hinting to a role of Jbtx-membrane interaction as the basis for its toxicity. The present study addresses the structural aspects of this interaction by investigating the behaviour of Jbtx when in contact with membrane models, using nuclear magnetic resonance and circular dichroism spectroscopies in the absence or presence of micelles, large unilamellar vesicles, and bicelles. Fluorescence microscopy was also used to detect protein-insect membrane interaction. Significant differences were observed depending on the type of membrane model used. The interaction with negatively charged SDS micelles increases the secondary and tertiary structure conte