Effect of L-Proline on the phase state transition of model lipid membranes under hydric stress conditions

VILLALBA, ARACELLI; FRIAS MARÍA DE LOS ANGELES; DISALVO EDGARDO ANIBAL; ROSA ANTONIO SEBASTIÁN

Rosario

Congreso; L Reunión Anual de la Sociedad Argentina de Biofísica; 2022

Sociedad Argentina de Biofísica

L-Proline is an amino-acid with hydrophobic characteristics that plays a highly beneficial role in plants exposed to different abiotic stress conditions, gathering at certain plant tissues and maintaining the cellular membrane integrity under these conditions.The aim of this work is to study the effect of L-Proline on the gel-liquid crystalline phase state transition of dimyristoylphosphatidylcholine (DMPC) model membrane, using infrared spectroscopy (FTIR-ATR), at different temperatures under controlled relative humidity conditions.In order to quantify the system’s hydration degree, the relative water content was analyzed following the area ratio between the water stretching band (3000 – 3800cm-1) and the bands corresponding to methyl and methylene stretching groups. The phase state transition was determined by the analysis of methylene (CH2), carbonyl (CO) and phosphate (PO2-) groups.The results show an increase in the water content in the system and a decrease of the transition temperature, approximately 5°C compared to the control under the same conditions, in presence of L-Proline in a 1:1 ratio, under hydric stress conditions.It can be concluded that the thermotropic effect of L-Proline on the DMPC membrane would be the responsible of the mechanism of protection that the amino-acid exerts on the membrane under stress, bringing its hydration degree closer to that of a membrane without stress. This would allow to keep certain physiological functions active in the cell in hydric stress conditions.