Conformational changes of β-lactoglobulin induced by anionic phospholipid

Conformational changes of β-lactoglobulin (β-LG) induced by anionic phospholipid (dimyristoylphosphatidylglycerol, DMPG) at physiological conditions (pH 7.0) have been investigated by UV-VIS, circular dichroism (CD) and fluorescence spectra. The experimental results suggest that β-LG-DMPG interactions cause β-LG a structural reorganization of the secondary structure elements accompanied by an increase in α-helical content, and a loosening of the protein tertiary structure. The interaction forces between β-LG and DMPG are further evaluated by fluorescence spectra. The fluorescence spectral data show that conformational changes in the protein are driven by electrostatic interaction at first, then by hydrophobic interaction between a protein with a negative net charge and a negatively charged phospholipid.