The FTIR and SAXS studies of influence of a morpholine derivatives on the DMPC-based biological membrane systems

Fourier transformed infrared (FTIR) spectroscopy and small-angle scattering of synchrotron radiation have been used to analyze the influence of two zwitterionic surfactants of the sulfobetaine structure (3-(N-decylmorpholine)-1-propansulfonate and 3-(N-tetradecylmorpholine)-1-propansulfonate) on the conformational dynamics of CH2 and O–P–O groups of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and the structure of phospholipid bilayers. The presence of the surfactant causes changes in the DMPC phase transition temperature. Our small-angle X-ray scattering (SAXS) data analysis implies a gradual disappearance of the lamellar phase typical of DMPC and a probable formation of the bicellar phase or cubic phase in DMPC/surfactants system.