Melittin-GM1 interaction: a model for a side-by-side complex.
We report here the interaction of melittin with ganglioside GM1 by steady-state fluorescence, one-dimensional (1)H NMR spectroscopy and molecular modeling. In the presence of GM1 the emission maximum of melittin is blue shifted and fluorescence quenching efficiencies of iodide and acrylamide are substantially reduced, indicating a shielding of tryptophan of melittin from aqueous environment. Significant line broadening of NMR resonances of melittin, suggestive of motional restriction, is observed. Molecular modeling indicates a melittin-GM1 complex with N-terminal hydrophobic stretch of melittin associating with the ceramide tail and C-terminal hydrophilic end of melittin having favorable electrostatic interaction with the carbohydrate head group of GM1.
Chatterjee
Chiradip
C
Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700 009, India.
Mukhopadhyay
Chaitali
C
D003198:Computer Simulation; D005677:G(M1) Ganglioside / Q000737:chemistry* / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions; D046911:Macromolecular Substances; D008555:Melitten / Q000737:chemistry* / Q000378:metabolism*; D008823:Micelles; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D013050:Spectrometry, Fluorescence; D055672:Static Electricity; D014364:Tryptophan / Q000737:chemistry
D046911:Macromolecular Substances; D008823:Micelles; D008555:Melitten; D005677:G(M1) Ganglioside; D014364:Tryptophan