Fig. 3
Lipid binding ability of recombinant NmPin. a Coomassie stained SDS-PAGE of 15 μM NmPin (wildtype, black; NmPinK7E/K34E, red; NmPinK7E, blue) as well as 15 μM CsPinA (grey) in the presence of different concentrations of brain lipid extract (BLE). Layers resemble the amount of protein found in either the soluble or the lipid bound fraction after sedimentation (lipid sedimentation assay). The amounts of BLE are annotated above and the corresponding protein fractions are indicated below. b Electrostatic surface potential of wildtype NmPin (black), NmPinK7E/K34E (red) and NmPinK7E (blue) calculated with Particle Mesh Ewald approach (PME). The intensity of the potential is indicated by a color gradient from dark red (negative), over grey (neutral), to dark blue (positive) ranging from –350 to +350 kJ/mol. The mutants K7E/K34E and K7E were modeled using residue swaps in YASARA prior to calculation of the electrostatic potential. c Circular dichroism spectra of NmPin (black), NmPinK7E (blue) and NmPinK7E/K34E (red) shown as mean residue ellipticity (mrw). *Datasets were normalized to the wildtype spectrum for better comparison of the three protein folds