Spectroscopic investigation on alteration of dynamic properties of lipid membrane in presence of Gamma-Aminobutyric Acid (GABA)

The effect of neurotransmitters on the cell membrane is an elegant topic to be explored in the arena of chemistry and biology, particularly with respect to the understanding of various neurological disorders. In this present study, based on various spectroscopic and microscopic results, we find the alteration of membrane properties of model phospholipid vesicles due to interaction with the neurotransmitter Gamma-Aminobutyric Acid (GABA). The solvation dynamics and anisotropy measurements indicate the increased hydration and enhanced fluidity of lipid membrane in presence of GABA. An increased microheterogeneity of membrane system is reflected from fluorescence lifetime imaging microscopy (FLIM) study. Further, the zeta potential and 31PNMR spectroscopy confirm the mode and site of interaction of GABA to the membrane. The fluorescence correlation spectroscopy (FCS) measurement indicates that the dye molecules in the GABA-containing vesicles are diffusing at a slower rate due to the formation of large vesicular entity. Therefore, we establish the effect of interaction of elevated concentration of GABA with membrane, like, alteration of dynamic aspects, perturbation of membrane morphology, variation of rotational and translational diffusion properties of dye molecules in the vesicle, which would conspicuously research the status of the phospholipid membrane in presence of GABA under various neurological disorders.